Impact of tung oil on a sustainable bio-based polymer, and development by zinc oxide nanoparticles

ABSTRACT The use of natural and bio-based materials instead of petrochemicals is strongly recommended for reducing greenhouse gas emissions. Here we aim to promote the environmentally

friendly bio-based polyester (P), prepared from biomass, with natural Tung oil (TO) plasticizer and zinc oxide nanoparticles (ZnO NPs) filler by 10–50%, and 3% to get a sustainable

nanocomposite. The grafting altered the profile of neat P. Owing to insufficient contents, low concentrations have a slight impact, and high concentrations have more enhancements. The

physical properties accompanied by curing of P/TO copolymer showed a decrease in viscosity, gelation time, and gelation-curing period for TO-based specimens, besides the lower heat emission

during curing reaction, compared with that of P, by 3.4% and 4%, respectively, for P/TO-40 and P/TO-50 copolymers. The stability against exudation was promoted by 48.6%, where all

concentrations of composites are more stable than P. P/TO-40 and P/TO-50 improved creep resistance by 62% and 88.1%, respectively, due to the stable surfaces. Furthermore, P/TO-50

concentration reduced hardness by 25%, but it was improved by ZnO NPs by 46.7%. Both TO plasticizer and nanofiller make the polymer capable of absorbing the flexural loading as a toughened

composite. The proposed composites provide positive effects on the thermal behavior. Particularly, the P/TO-50 formula decreased the value of tan Delta by 35.5%; all composites increased

T_g_ as well. The obtained data-results and SEM photos confirm the grafting and good distribution of TO plasticizer and ZnO NPs into P matrix through an improved and stable homogeneous

bio-based polymer nanocomposite. SIMILAR CONTENT BEING VIEWED BY OTHERS ENHANCING IMPACT RESISTANCE AND BIODEGRADABILITY OF PHBV BY MELT BLENDING WITH ENR Article Open access 31 December

2022 THE INFLUENCE OF BIO-BASED MONOMERS ON THE STRUCTURE AND THERMAL PROPERTIES OF POLYURETHANES Article Open access 23 November 2024 IMPACT OF Γ-IRRADIATION AND SBR CONTENT IN THE

COMPATIBILITY OF AMINATED (PVC/LLDPE)/ZNO FOR IMPROVING THEIR AC CONDUCTIVITY AND OIL REMOVAL Article Open access 15 November 2022 INTRODUCTION Recently, the use of natural products and

environmentally friendly materials to reinforce polymers has been encouraged to achieve the goals of sustainable development. It is well known that polyester is considered one of the most

commonly applied polymers; some of its applications are construction laminations, printed products, coating, cast forms and blocks, etc1,2. In spite of its good characteristics, polyester

suffers from brittleness, moderated thermal stability, low bending properties, and other related disadvantages3. With incorporation of novel reinforcements and fillers, the characteristics

of traditional materials may be altered. Consequentially, reinforcements are included in the conventional materials to enhance their diverse qualities4. For the plasticizing filler, its

effectiveness was found to change the mechanical properties of the polymer matrix5. Because of the industrial source of these fillers, the applications of their composites are limited due to

lack of sustainability, and harmful effects on the environment. Different recycled materials, like solid waste, recycled and low-carbon materials, can be used and exploited as

additives/fillers for preparing sustainable and low-carbon composite products6,7,8. Other polymers are subjected to recycling, and compounded within other reactants for production of new

low-cost products9,10. Bio-based polyesters represent a promising area of research and development, driven by the need for sustainable materials. Their production involves various synthetic

strategies that yield polymers with diverse properties suitable for a wide range of applications. Continued advancements in the synthesis and modification of these materials are essential

for overcoming existing limitations and enhancing their commercial viability. Bio-based polyesters are a class of polymers synthesized from renewable resources, such as plant-based materials

and microorganisms, which offer a sustainable alternative to petroleum-derived polyesters. The primary structures of bio-based polyesters typically consist of ester linkages formed through

the polymerization of bio-derived diacids and diols. Common examples include polylactic acid and polybutylene succinate, which are derived from lactic acid and succinic acid, respectively.

These materials are characterized by their biodegradability, biocompatibility, and reduced toxicity, making them suitable for various applications. The structural characteristics of

bio-based polyesters play a crucial role in determining their properties11,12,13. The production of bio-based polyesters generally involves two main synthetic routes: polycondensation and

polymerization. In the first, diols and diacids react to form polyesters while releasing water. The polymerization allows for the tuning of molecular weight and crystallinity, which

significantly affects the thermal and mechanical properties of the cured polymer14,15. The trend of utilizing ecofriendly additives is increasing, especially natural products16,17,18. Tung

oil, as a natural oil type, is a triglyceride material extracted from Tung trees. Mainly, it contains unsaturated acids, such as eleostearic, oleic, and linoleic acids; such nature

facilitates the compounding with polymers throughout functional sites19,20. Some trials were reported focusing on utilization of Tung oil for plasticization and controlling the properties of

different polymeric matrices. Unsaturated polyester-dicyclopentadiene polymer was modified with Tung oil by melting polycondensation and then blended with styrene comonomer to give a cured

and tough polymer. The impact and tensile properties were changed due to the Tung oil-based polymer as an alternative to petroleum-based additives21. Tung oil with chitosan, as second

filler, developed epoxy resin; the mechanical and thermal properties of the polymer were adjusted through crosslinking among all contents22. Another epoxy type was toughened by cyano-treated

Tung oil. Compared with epoxy, the investigations on thermal, surface, and mechanical properties conducted on cured samples showed a significant improvement, compared with industrial

types23. For a green plasticizer, vegetable oil modifiers allowed for varying the properties of Tung oil networks obtained by polymerization to increase the efficiency of Tung oil. The

proposed treatment provided a good damping effect in different conditions24. A new polymer-modified Tung oil waterborne varnish was developed. The green product improved the thermal and

mechanical stability and insulation, and decreased water adsorption, in addition to the waterborne ability25. A Tung oil-maleic triglycidyl ester was synthesized and included in polyvinyl

chloride as a replacement for dioctyl phthalate plasticizer; the interaction between the polymer and the recommended modified ester was attempted26. Regarding the overall superior profile,

it was reported that nanoparticles of numerous metal oxides play a vigorous role in endorsing the thermal behavior of materials in addition to their mechanical, catalytic, electrical,

isolative, physical, and other characteristics. Of them, the environmental zinc oxide nanofiller is an effective type27,28,29,30,31,32. In addition, nanoparticles of green carbonates have

been applied to promote the thermal and mechanical properties of low-profile polymers33,34. ZnO and ZnS were adsorbed and utilized as a potential fire-retardant coating on fabrics. The

hybrid material was found to alter factors such as heat release rate, smoke emission, and mass loss rate32. In a related study, ZnO NPs were precipitated on fabric surfaces along with a type

of phosphonopropionamide. Different modes of analysis confirmed the deposition of zinc and phosphorus components, in addition to the fire-retardancy impact35. Another coating material, as

transparent layers comprising ZnO NPs and organophosphate, was fabricated. As well as the smoke suppression, fire and aging protection, and antimicrobial performance, ZnO improved the

mechanical properties and transparency profile36. An organometallic composite, containing zinc, iron, phosphorus, and aminopyridine, was formulated on epoxy polymer. The dissociation of

polymers into more aromatic structures could form dense carbon shielding layers37. Another thermosetting epoxy coating was grafted by a dual system of precipitated ZnO NPs/charring foaming

agent, altering the thermal decomposition, increasing char formation, and minimizing oxygen flow38. New nanocomposites, containing chitosan-modified ZnO NPs and aromatic polyamide, were

designed by solution casting for filling polyvinyl chloride. Both additives stabilized the matrix, and increased the tensile strength and mass-loss temperature39. The influence of

polysiloxane-treated ZnO NPs on polypropylene was studied. Compared with the neat matrix, the 16 wt% loading percentage succeeded in passing the UL 94v-0 standard and increasing the limiting

oxygen index and tensile strength. Also, the polymer kept a smooth surface with accepted mechanical properties after UV irradiation40. In another thermoplastic polymer, hybrid nanofillers

based on cellulose nanocrystals and ZnO NPs were investigated for promoting extruded polylactic acid regarding mechanical and thermal characteristics. The combination of 1.5% enhanced the

mechanical and thermal characteristics, and increased char formation. However, the sole ZnO NPs hastened the thermal degradation of polylactic acid, and decreased its modulus value due to

incompatibility41. ZnO NPs and phosphazene-triazine bigroup were doped, and added to polylactic acid; although the decline occurred in the mechanical properties, the thermal effect was

promoted because of the decomposition to low molecular segments, and char-forming molecules42. This study aims to prepare and characterize a novel environmentally friendly nanocomposite

using bio-based polyester, natural Tung oil, and zinc oxide nanoparticles. The synergetic effect of both additives on the physical, mechanical, and thermal characteristics is studied in

details to enhance the bio-based polyester. Related to the aspects of UNSDGs, in particular the SDGs 12 and 13 that belong to sustainable consumption and production and climate change, the

proposed sustainable composites target these goals regarding preserving and recycling natural resources and waste, reducing climate change, innovation, and promoting economic growth.

Modifying the bio-based polyester with these materials is a possible utilization of sustainable products compared with petroleum-based polymer. EXPERIMENTAL AND METHODS MATERIALS AND

PREPARATIONS The materials used in this paper are indicated here. Tung oil (TO) plasticizing derivative type, obtained from Shandong-Deshang Chemical Ltd. with a viscosity of 203 cP, was

taken as the green plasticizer additive. Zinc oxide nanoparticles (ZnO NPs) were used as the nanofiller modifier; they were obtained from Alfa Aesar Chemicals with an average particle size

of ~ 70 nm. The polymer needed to be modified is the bio-based polyester (P) that was prepared from biomass waste43. Briefly, a biomass mixture waste was subjected to liquification process,

and then was reacted with oleic acid to get this bio-based polyester. The structure of P matrix is given in Fig. 1. Methyl ethyl ketone peroxide type, purchased from Singapore Highpolymer,

was the catalytic agent. Experimentally, the modification of P was accomplished as indicated in the following steps: The bio-based P matrix was modified by TO plasticizer with different

concentrations between 10% and 50% to produce P/TO-10, P/TO-20, P/TO-30, P/TO-40, and P/TO-50 copolymers. As per the low cost and availability of TO plasticizer, there will be a reduction of

the total cost by about 18% in case of consuming 50% TO. Grafting TO onto the polyester backbone was performed by solution mixing. Both liquid phases were mixed with the help of stirring

and ultrasonication. The produced copolymer is composed of a mixture of unsaturated polyester, which originated from liquefied biomass and oleic acid, and unsaturated Tung oil plasticizer.

ZnO NPs were also added by 3% to promote some characteristics, as given in the discussion section. ZnO NPs were incorporated into the P/TO matrix by solution mixing. The viscosity of

P/TO-50/ZnO NPs system reads 330 cP, which is close to that of P/TO-50, after mechanical mixing and ultrasonication. In the related specimens, TO and ZnO NPs filler were added to the

polyester matrix. In an ice bath, ultrasonic waves were applied for mixing, and then mechanical stirring was adjusted for about 20 min. The application of ultrasonic waves and further

mechanical stirring causes a good distribution of fillers in the matrix, as presented later by SEM photos. The crosslinking of proposed composites was promoted by the gentle mixing of 1%

methyl ethyl ketone peroxide with the prepared formulas for one minute at room temperature. The whole system was mixed gently to let al.l ingredients contact each other completely. Finally,

the composites were kept overnight at room temperature, then heated to 65 °C for 2 h for completion of crosslinking reaction44,45. INVESTIGATIONS The following investigations were conducted

to analyze the prepared copolymers and composite. The viscosity of polymers was identified by the Brookfield-DV2 T digital viscometer following ASTM D-789. The polymer reactivity, including

gelation time, curing temperature, and gelation-curing period, was identified following ASTM D2471. The polymer specimens were poured in cups; after adding the curing agent, the gelation

phase was checked by a glass rod where the polymer starts to stick with this rod. Both gelation time and gelation-curing period are calculated by a stopwatch. The stability of composites to

exudation was measured by calculating the exudation percentage as the weight loss after laying the specimen between couples of filter papers at 50 °C for 24 h. The underlying mechanism for

the improved stability originates from the low exudation percentage, where the specimen doesn’t exude more of its contents. The lower the exudation percentage recorded, the more improved

stability is for the specimen; the exudation percentage is expressed using Eq. 126, where m and m` denote respectively the initial weight and the weight after exposing the specimen to

exudation conditions. > $$\hbox{Exudation percentage}\ (\%) = (m - m`)/m \times 100$$ >  (1) The morphology was detected by a scanning electron microscope (FEI Nova NanoSEM 450) using

the backscattered electrons SEM imaging with a 5 kV accelerating voltage. The taken specimens were coated with gold before capture. The WANCE creep rupture machine was used to investigate

the creep resistance of composites, following ASTM D 2990. Specimens with dimensions of 3 × 10 cm2 were fixed on the testing plate in the tensile mode at room temperature. The testing was

executed at a stress of 10 N for determining the creep response. The Barcol impression test was conducted to identify the hardness of P and its proposed products following ASTM D 2583. The

Barcol hardness is measured through indentation of the impressor’s needle into the specimen; the penetration indenter reads the hardness value. The type of Gardco Barcol impressor was used

by applying a constant manual impression to 5 × 5 cm2 specimens. The effect of environmental modifiers on the flexural strength was studied by the XLC H-universal testing machine according

to ASTM D 790. About 1.3 × 12.7 cm2 specimens were subjected to increased flexural load till failure. The bending test was performed by 3-point bending mode, with measuring the flexural

strength parameter. The thermal analysis of composites was evaluated by the dynamical mechanical analyzer (DMA) using the NEXTA machine following the standard of ASTM D 4065. The

corresponding glass transition temperature and damping peak parameters were identified. Specimens with dimensions of 1 × 5 cm2 were heated gradually from room temperature to 120 °C under

flexural force for detecting the related thermal properties. The response surface methodology (RSM) statistical analysis was projected by the Box-Behnken designing to study the significance

and effect of the presented treatmet factors on the resulting responses. RESULTS AND DISCUSSION CURING OF COPOLYESTER The physical properties accompanied with the curing of the copolyester

are studied here. Respectively, Figs. 2(a), (b), (c), and (d) illustrate the viscosity, gelation time, curing temperature, and gelation-curing period for the bio-based polyester, and its

Tung oil-based copolymer. As per Fig. 2(a), the viscosity of the proposed polyester is altered. Different polymers become less viscous when plasticizers or toughening materials are

incorporated due to the easier slipping of polymer layers on each other46,47. Actually, TO has a viscosity of 203 cP, which is lower than that of polyester (420 cP). So, the overall

viscosity reduced after mixing. This is noticed in the viscosity measured for P/TO-10, P/TO-20, P/TO-30, P/TO-40, and P/TO-50 that gave 411, 401, 388, 354, and 315 cP, respectively, compared

with 420 cP of neat P. There are two points to be demonstrated: Firstly, the viscosity of the prepared copolymer decreased with the addition of Tung oil due to its plasticizing effect and

low viscosity, compared with the viscosity of polyester. Secondly, the prepared copolymer liquid, including polyester base and TO plasticizer, was subjected to curing reaction by addition of

peroxide curing agent. During the curing process, a crosslinking reaction occurred at the unsaturation sites in copolymer. This is accompanied by the viscosity increase reaching the

gelation step; this is a normal routine regarding the crosslinking of polymers48. Further curing takes place that converts the polymer into solid material. This observed change in viscosity

is significant because it will be easier to disperse and distribute the desired fillers well in the low-viscous solution in a shorter time before curing; the industrial processing is easier

in this case. With the curing reaction, the prepared composites get hardened, taking the applicable improved stable form. Figure 2(b) describes the minutes taken for the gelation step. It is

noticed that the higher content of Tung oil has decreased the gelation time to very fewer minutes. In other words, the copolymer becomes more active toward the curing reaction. The P/TO-50

specimen has a gelation timing of 24 min, compared with 27 min for the neat polymer. The reduced gelation time may be attributed to the abundant unsaturation sites in the natural oil

modifier along with the unsaturation sites in the polymer, in addition to the differentiation in the properties of both materials, mainly viscosity, even after mixing together. Basically,

the properties of the polymer base are changed during the curing reaction; the liquid resin starts to be crosslinked and converted to the hard form, passing the gelation phase. Actually,

reducing gelation time to 24 min in P/TO-50 is a good result, where only 20 min is adequate time appropriate for mixing all fillers in the matrix before the viscosity increases, reaching the

gel phase. Thus, the 24 min support and facilitate the facile practical implications for mixing fillers during the preparation phase, especially with the low-viscous P/TO-50 specimen, which

doesn’t require longer time for mixing. After gelation step, the curing continues to take place rapidly alongside the temperature increase. The curing temperature reflects the exothermic

property of curing reaction. The crosslinking of unsaturation sites in the resin is accompanied by heat release. It is a good property that the reaction releases lower heat, which is noticed

in the proposed composites (Fig. 2(c)). The preparation doesn’t consume energy for heating, as it is an exothermic type. The maximum curing temperatures of P, P/TO-10, P/TO-20, P/TO-30,

P/TO-40, and P/TO-50 recorded 130.6 °C, 130 °C, 129.3 °C, 127.7 °C, 126.1 °C, and 125.4 °C, respectively. The observed decrease in curing temperature, particularly in P/TO-40 and P/TO-50

copolymers, indicates lower heat emission during the curing reaction, compared with that of P specimen, by 3.4% and 4%, respectively. Furthermore, Fig. 2(d) indicates the time taken starting

from the gelation step to the maximum curing temperature reached, defined as the gelation-curing period. The oil plasticizer showed a little change in the gelation-curing period, as

expected. The effective concentrations are appear to be the P/TO-30, P/TO-40, and P/TO-50 copolymers that alter the gelation-curing timing of P from 7 to 6, 5.1, and 4.7 min, respectively.

The Tung oil plasticizer showed a change in the gelation-curing period. It decreased this period regarding blending more contents of the toughening oil containing unsaturation; the new blend

has more unsaturation sites available for active curing. Also, the change in this period and the related physical properties presented in all figures infer the successful grafting and

curing of composite. EXUDATION TEST With this test, the stability of composite against exudation is identified. As per Fig. 3, all copolymers have almost the same weight in comparison with

P. The absence of weight loss reflects the stability of TO plasticizer in P matrix with concentrations up to P/TO-50. Furthermore, the nanocomposite containing ZnO NPs has the best stability

regarding the least percentage of exudation, where the exudation stability was promoted by 48.6%. This improved performance is owing to the progressive filling effect of ZnO NPs as a

physical improver. Actually, the nanofiller itself could enhance the physical properties and stabilize the matrix from the environmental conditions, such as exudation, especially in the case

of the compatible and well-distributed interface. The P/TO-50/ZnO NPs system sharply decreases the exudation percentage. This scenario matches with that reported elsewhere49, where the

incorporated high-surface-area nanofillers could decrease the degree of exudation. Besides, all proposed concentrations are more stable than neat P due to the molecular matching. Such data

approve the successful grafting of TO and ZnO NPs into the matrix For confirming such grafting and dispersion of nanofiller in polymer, the surface morphology is provided. The low and high

SEM magnifications of the optimized P/TO-50/ZnO NPs nanocomposite are represented in Figs. 4(a) and (b). It is clear that ZnO NPs are located within the matrix with a distributive property.

The filler appears to be spread and grafted over the matrix (exfoliation interface without agglomeration) thanks to the compatibility and good dispersion of fillers in the host polymer upon

mechanical stirring and sonication. In other words, the proposed composite system has a filler-grafted surface where fillers and polymer attach to each other effectively. This behavior is

clear in the different positions shown in both figures. Basically, TO, as a liquid acid material, was distributed in P polyester matrix liquid phase. Because of the similarity in TO and P

natures, their mixture became homogeneous as one phase without separations. This result is noticed by SEM, where the cured polymer provides one phase; the distributed particles screened in

morphology stand for the ZnO NPs additive. Such discussion approves the successful grafting and the promoted exudation properties discussed in Fig. 3. As the diffusion of the filling

material and plasticizer is established on the contact among all components, the proposed bio-based composites show good intermolecular interaction amongst the polyester matrix, Tung oil,

and zinc oxide nanoparticles that provide a stable physical character. CREEP TEST The creep measurements for P, plasticized concentrations of P/TO, and P/TO/ZnO NPs nanocomposite are given

in Fig. 5. The presented diagram of creep deformation shows the longest creep displacement for the neat polymer (5.79 mm), so more deformation occurred (low creep resistance) compared with

the TO- and ZnO NPs-incorporated specimens. The longer creep length reflects the unstable surface of the polymer, which suffers from distortion changes in the polymeric segments. On the

other hand, the specimens record shorter creep displacements (high creep resistance) in the case of plasticizing with TO. The more content of TO to be added, the higher the resistance to

creep is attained due to the low numbers of creep displacement, as clear in Fig. 5. It is known that the short deformation displacement reflects the stability of the polymer surface50,51.

Some materials, such as polymers and rubbers, have an elastic nature. When the polymer is subjected to an external force, its segments absorb the force and get stressed. The elastic property

lets the stretched segments relax and return to their geometry without failure52,53. The elastic material may be a crosslinked one, like crosslinked soft polymers, and this crosslinking may

not decline the elasticity nature. Furthermore, the plasticized polymers act as highly elastic materials, as the plasticizer could soften their chains and facilitate their recovery.

Consequently, the polymer gives good data-results on the resistance to creep and external forces, especially if it is plasticized as in TO-incorporated specimens. If this recovery force or

elastic recovery is able to compensate for the applied force, the polymer shall resist creep, and vice versa. In our case, TO plasticized the taken polymer, so it smoothes and softens the

polymer surface. The new surface tries to recover the deformation occurred via the applied creep forces. The resulting deformation (creep displacement) is minimized accordingly, which is

highly noticeable with the P/TO-50 copolymer by 88.1%; hence, TO improves creep resistance. The addition of ZnO NPs increased the creep displacement in a minor value due to the stiff

nanoparticles; however, it is still lower than neat polymer. The final composite promoted the creep resistance. In other words, TO plasticizer stores the stress applied on P and mends it by

returning the mobile/stressed segments to their original positions. Accordingly, the TO avoids the creep deformation and reduces creep displacement. For the practical applications, the

proposed plasticized composites are beneficial for boosting the overall performance of bio-based copolymers based on compensating for the creep displacement in addition to the improved

flexural behavior. Overall, the proposed modifying materials offer an entanglement to the polymer segments and control the deformation of the overall composite. IMPRESSION TEST The

impression test was performed to neat P, P/TO copolymers, and P/TO/ZnO NPs nanocomposite to investigate the effectiveness of TO and ZnO NPs on the hardness. Firstly, the TO-based specimens

with low concentrations have a minor effect on hardness with a small reduction in the hardness values, as provided in Fig. 6. Adding more concentrations of TO results in plasticizing the

polymer segments and altering their mechanical properties. This behavior demonstrates the specimen’s capacity to tolerate imposed hardness54. The highest concentration (P/TO-50) caused a

reduction in hardness by 25%. However, this concentration was promoted by the effect of ZnO NPs, where the hardness value of P/TO-50/ZnO NPs nanocomposite increased by 46.7%, compared with

the P/TO-50 specimen. The hardness of P/TO-50/ZnO NPs nanocomposite exceeded that of the blank P as well. From the results, there was an initial decrease in hardness values due to the

plasticizing effect of TO plasticizer (induced softness). On the other hand, the addition of ZnO NPs led to subsequent improvement in hardness due to the effect of stiff nanofiller, so the

surface became harder and could resist the applied force. The nanofiller itself is capable of developing the hardness of the different matrices in general; also, the filler distribution and

direction control the resulted enhancement55. Overall, ZnO NPs reinforce and stabilize the plasticized copolymer matrix by increasing its impressive hardness, even after adding the TO

plasticizer. FLEXURAL STRENGTH The effect of TO plasticizer and ZnO NPs on the flexural strength of P polymer is investigated; the results are illustrated in Fig. 7. The P, P/TO-10, P/TO-20,

P/TO-30, P/TO-40, and P/TO-50 specimens recorded flexural strength at 26 MPa, 26 MPa, 28 MPa, 29 MPa, 31 MPa, and 35 MPa, respectively. It is clear that the higher the content of TO added,

the more it positively affects the flexural properties. The obtained specimens have flexible behavior, where the plasticizing additive makes the polymer tougher. This is noticed especially

with the P/TO-50 concentration, which enhanced the flexural strength by 34.6%, compared with P. The flexural strength was increased further by the second addition of ZnO NPs, as it reads 36

MPa. TO and ZnO NPs caused improvement in the flexural strength, where they made the polymer capable of absorbing more loading without failure. The composites seem to bear additional

flexural force (more flexible design), compared with neat polymer. Furthermore, the Tung oil/ZnO-containing specimen has additional properties, such as hardness and stiffness, along with the

flexibility. Thus, this added-value hybrid composite can serve as an optimized formula for both flexible and durable applications. In conclusion, both TO and ZnO NPs fillers developed the

flexural strength of the proposed bio-based polymer, resulting in toughening the overall composite. THERMAL PROPERTIES The effect of TO and ZnO NPs materials on the thermal properties of

used P polyester is investigated by dynamical mechanical analysis. The values of tan Delta and the glass transition temperature (T_g_), as a function of the testing temperatures, are

determined. The tan Delta is a value that is calculated by the DMA software during testing. It is the quotient of loss factor by modulus. From the tan Delta-temperature curve, the

corresponding T_g_and damping peak parameters are identified for studying the thermal characteristics56. The tan Delta-temperature plateaus, including values of tan Delta peaks and T_g_

temperatures, are represented in Fig. 8. As the T_g_ is the temperature at which the polymer chains can move freely with more molecular motions, the T_g_ of polymers and polymer composites

is identified as the temperature located at the peak of tan Delta-temperature curve, where this peak elucidates the highest fraction of viscous response, compared with elastic response, with

increasing the free volume under the testing conditions of temperature increase. In other words, as tan delta numbers are the values between loss and storage modulus, their peak represents

the point between the glassy and rubbery phases. Identification of T_g_ from Tan delta curve is a new technique. Hence, the transition between the hard glassy phase and the rubbery phase

(tan Delta peak) of the taken polymer is expressed as its T_g_57,58. The thermal behavior of P and all specimens shows similar scenarios regarding two different phases: glassy (with

restricted mobility) and rubbery (viscous). The phases exist in the ranges of room temperature and ~ 75 °C, and from ~ 85 °C to ~ 110 °C, respectively. The obtained peaks are the transitions

present between these phases. It is clear that the highest peak belongs to the neat P polymer. Furthermore, adding more concentrations of TO results in dropping the peaks in the curves of

tan Delta-temperature. The low number of damping factor is based on the more flexural properties measured, so the proposed concentrations show reduced peaks dramatically. The P/TO-50 formula

has the least value of tan Delta (0.4) through a lowering percentage of 35.5%, compared with P. In addition, the P/TO-50/ZnO NPs nanocomposite has a low tan Delta-temperature peak.

Alteration of peaks in damping curves is well-known owing to the progressive effect of filling components on the associated viscoelastic properties59. The accurate values of tan Delta peaks

and T_g_ temperatures are identified separately in Table 1 for more clarification, as these numbers are not presented clearly in the large scale of temperatures present in the whole tan

Delta plateaus. For the T_g_ measurements, the addition of more concentrations of TO is accompanied by shifting the screened temperatures to higher ones. This is realized dramatically by

P/TO-10, P/TO-20, P/TO-30, P/TO-40, and P/TO-50 specimens that achieved T_g_ at 77.6 °C, 81.2 °C, 82.1 °C, 82.5 °C, and 83 °C, respectively, compared with 76.7 °C for neat P. The functional

unsaturation sites existing in TO plasticizer are expected to share with the curing reaction in conjunction with unsaturation sites in P polyester, where the polymerization takes place via a

dual system with heavy crosslinking sites. Some enhancement in T_g_ values is observed. Furthermore, the P/TO-50/ZnO NPs nanocomposite has increased T_g_ temperature by ~ 10%, due to the

diminution of free space and segmental mobility. The proposed fillers, especially ZnO, delay the softening of polymeric chains during heating; as for the mechanism of nanomaterials, the T_g_

values increase accordingly. The existing data reveal the successful blending of TO and ZnO NPs into the bio-based polyester that improves its glass transition temperature and thermal

properties. From the previous data, it is aimed to promote the properties of environmentally friendly plasticized polymer after adding different concentrations of TO plasticizer. In fact,

the improved P/TO-50 copolymer still has some drawbacks, such as low strength, although it is tougher and more elastic and has higher thermal stability and better physical properties. The 3%

ZnO NPs concentration was selected based on the literature on using NPs for enhancement of composites; different concentrations above 3% were found to form aggregated and heterogeneous

structures with inferior characteristics60,61. So, the 3% ZnO NPs concentration was chosen to adjust the preferred P/TO-50 formulation to improve other properties such as hardness. The

proposed hybrid was then taken as an optimized composite that possesses superior characteristics. STATISTICAL ANALYSSIS The response surface methodology (RSM) statistical analysis was

performed to compare the statistical difference between the treatments more effectively. The models were performed by ANOVA software. The considered coefficient of determination (R2) is

ranged between 73 and 95, which supports the adequacy of recognized models with empirical data62,63. Furthermore, the most important responses of exudation, creep, flexural, and T_g_, based

on the main factors, are represented in Fig. 9. The 3D response surface plots demonstrate that TO and ZnO NPs main parameters control the properties. The more recommended levels are

optimized by the TO 50% and ZnO NPs 3% treating factors as the highest efficient inputs. These results demonstrate that the model fits the empirical data effectively. The interaction between

inputs and the resulting influence on the responses supports the thermal and physical stability and the improved mechanical profile, as per what was noticed in the results and

characteristics provided before. CONCLUSION In this paper, natural Tung oil (TO) and zinc oxide nanoparticles (ZnO NPs) were utilized to modify the physical and mechanical properties of

bio-based polyester (P). The proposed copolymers were formulated successfully based on P/TO-10, P/TO-20, P/TO-30, P/TO-40, and P/TO-50 by wt%. The P/TO-50 copolymer was filled with 3 wt% ZnO

NPs to enhance its characteristics. Due to the plasticizing effect of TO, it was observed that adding TO reduced viscosity; the lowest viscosity was seen at greater concentrations. The

higher content of TO, particularly with P/TO-40 and P/TO-50 copolymers, shortened the gelation time and curing temperature. In addition, the P/TO-30, P/TO-40, and P/TO-50 copolymers showed

shorter gelation-curing periods regarding blending more natural toughening oil. The evaluation of exudation properties assured the stability of all TO-incorporated copolymers in comparison

with P. The P/TO-50/ZnO NPs nanocomposite achieved more stability with a lower exudation percentage due to grafting and distribution of ZnO NPs, as detected by SEM. Mechanically, the creep

data showed the longest displacement in neat P, compared with the TO-based specimens. Also, the proposed P/TO-50/ZnO NPs system displays an improved profile. For hardness, the concentrations

of TO caused a reduction in hardness; however, adding ZnO NPs improved the related value. In addition, both TO and ZnO NPs promoted the flexural strength of P; this reflects the flexural

behavior of the plasticizing filler. In the presence of TO and ZnO NPs, the brittle crosslinked polymer becomes toughened through the elastic recovery advantage. The gained features enhance

the material’s ability to keep the polymer as a reinforced enhanced product that withstands external mechanical forces without failure or deformation. Thermally, the neat P, P/TO copolymers,

and ZnO NPs-based nanocomposite show two different phases of glassy and rubbery regions. The highest peak in tan Delta-temperature curves belongs to the neat P polymer. However, grafting TO

altered the peak due to the more flexural property in proposed composites. Furthermore, it was found that T_g_ was enhanced by including more concentrations of TO and ZnO NPs fillers

compared with neat P. The results of statistical analysis demonstrate the interaction between inputs and ensuing responses as detected by different testings. The proposed additives support P

matrix with stability against applied mechanical forces and physical conditions via a new paradigm to design bio-based composites for potential applications. DATA AVAILABILITY All data

generated or analysed during this study are included in this published article. REFERENCES * Ortiz-Ortiz, D. N. et al. Synergistic effect of physical and chemical Cross-Linkers enhances

shape fidelity and mechanical properties of 3D printable Low-Modulus polyesters. _Biomacromolecules_ 24, 5091–5104 (2023). Article  CAS  PubMed  Google Scholar  * Phiri, R., Rangappa, S. M.,

Siengchin, S., Oladijo, O. P. & Dhakal, H. N. Development of sustainable biopolymer-based composites for lightweight applications from agricultural waste biomass: A review. _Adv. Ind.

Eng. Polym. Res._ 6, 436–450 (2023). CAS  Google Scholar  * Naguib, H. M. Environmental-friendly recycled Polyester/Mg(OH)2 nanocomposite: Fire-retardancy and thermal stability. _Polym.

Test._ 72, 308–314 (2018). Article  CAS  Google Scholar  * Yadav, R., Singh, M., Shekhawat, D., Lee, S. Y. & Park, S. J. The role of fillers to enhance the mechanical, thermal, and wear

characteristics of polymer composite materials: A review. _Compos. - A: Appl. Sci. Manuf._ 175, 107775 (2023). Article  CAS  Google Scholar  * Bakar, M. & Djaider, F. Effect of

plasticizers content on the mechanical properties of unsaturated polyester resin. _J. Thermoplast Compos. Mater._ 20, 53–64 (2007). Article  CAS  Google Scholar  * Hou, G. et al. Composition

design and pilot study of an advanced energy-saving and low-carbon Rankinite clinker. _Cem. Concr Res._ 127, 105926 (2020). Article  CAS  Google Scholar  * Naguib, H. M. & Zhang, X. H.

Advanced recycled polyester based on PET and oleic acid. _Polym. Test._ 69, 450–455 (2018). Article  CAS  Google Scholar  * Hou, G. et al. Microstructure and mechanical properties of

CO2-cured steel slag brick in pilot-scale. _Constr. Build. Mater._ 271, 121581 (2021). Article  CAS  Google Scholar  * Abdelsattar, D. E. et al. Effect of polymer waste mix filler on polymer

concrete composites. _ACS Omega_. 8, 39730–39738 (2023). Article  CAS  PubMed  PubMed Central  Google Scholar  * Naguib, H. M. et al. Environmentally friendly polymer concrete: polymer

treatment, processing, and investigating carbon footprint with climate change. _ACS Omega_. 8, 8804–8814 (2023). Article  CAS  PubMed  PubMed Central  Google Scholar  * Taha, T. Z., Ádámné,

M. A. & Ronkay, F. Effect of reprocessing on the crystallization of different polyesters. _Acta Tech. Jaurinensis_. 17, 1–7 (2023). Article  Google Scholar  * Abdel Rehim, M. H.

Bio-based polyesters for ecofriendly packaging materials. _Egypt. J. Chem._ 65, 1145–1153 (2022). Google Scholar  * Zhang, H. et al. Development of High-Molecular-Weight fully renewable

biopolyesters based on oxabicyclic Diacid and 2,5-Furandicarboxylic acid: promising as packaging and medical materials. _ACS Sustainable Chem. Eng._ 9, 6799–6809 (2021). Article  CAS  Google

Scholar  * DeRosa, C. A., Kua, X. Q., Bates, F. S. & Hillmyer, M. A. Step-Growth polyesters with biobased (_R_)-1,3-Butanediol. _Ind. Eng. Chem. Res._ 59, 15598–15613 (2020). Article 

CAS  Google Scholar  * Taguchi, S. et al. A microbial factory for lactate-based polyesters using a lactate-polymerizing enzyme. _Proc. Natl. Acad. Sci._ 105, 17323–17327 (2008). Article  ADS

  CAS  PubMed  PubMed Central  Google Scholar  * Liu, X., Lebrun, L. & Desilles, N. Enhancing thermal and mechanical properties of pyridine-based polyester with isosorbide for high gas

barrier applications. _Eur. Polym. J._ 202, 112629 (2024). Article  CAS  Google Scholar  * Abo-Shanab, Z. L., Ragab, A. A. & Naguib, H. M. Improved dynamic mechanical properties of

sustainable bio-modified asphalt using agriculture waste. _Int. J. Pavement Eng._ 22, 905–911 (2021). Article  CAS  Google Scholar  * An, J., Roh, H. H., Jeong, H., Lee, K. Y. & Rhim, T.

Rapid assessment of Di(2-ethylhexyl) phthalate migration from consumer PVC products. _Toxics_ 12, 7 (2024). Article  CAS  Google Scholar  * Silva, J. A. C., Grilo, L. M., Gandini, A. &

Lacerda, T. M. The prospering of macromolecular materials based on plant oils within the blooming field of polymers from renewable resources. _Polymers_ 13, 1722 (2021). Article  CAS  PubMed

  PubMed Central  Google Scholar  * Murawski, A. & Quirino, R. L. Bio-Based composites with enhanced Matrix-Reinforcement interactions from the polymerization of α-Eleostearic acid.

_Coatings_ 9, 447 (2019). Article  CAS  Google Scholar  * Liu, C. et al. Use of Tung oil as a reactive toughening agent in dicyclopentadiene-terminated unsaturated polyester resins. _Ind.

Crops Prod._ 49, 412–418 (2013). Article  CAS  Google Scholar  * Song, H. et al. Sustainable and mechanically robust epoxy resins derived from Chitosan and Tung oil with proton conductivity.

_J. Appl. Polym. Sci._ 140, e53857 (2023). Article  CAS  Google Scholar  * Xiao, L. et al. Tung Oil-Based modifier toughening epoxy resin by sacrificial bonds. _ACS Sustain. Chem. Eng._ 7,

17344–17353 (2019). Article  CAS  Google Scholar  * Meiorin, C., Aranguren, M. I. & Mosiewicki, M. A. Polymeric networks based on Tung oil: reaction and modification with green oil

monomers. _Eur. Polym. J._ 67, 551–560 (2015). Article  CAS  Google Scholar  * Cao, M. et al. Preparation and properties of epoxy-modified Tung oil waterborne insulation varnish. _J. Appl.

Polym. Sci._ 132, 42755 (2015). Article  Google Scholar  * Chen, J., Wang, Y., Huang, J., Li, K. & Nie, X. Synthesis of Tung-Oil-Based triglycidyl ester plasticizer and its effects on

Poly(vinyl chloride) Soft Films. _ACS Sustain. Chem. Eng._ 6, 642–651 (2018). Article  CAS  Google Scholar  * Sharma, V., Agarwal, S., Mathur, A., Singhal, S. & Wadhwa, S. Advancements

in nanomaterial based flame-retardants for polymers: A comprehensive overview. _J. Ind. Eng. Chem._ 133, 38–52 (2024). Article  CAS  Google Scholar  * Favarim, H. R. & Leite, L. O.

Performance of ZnO nanoparticles for fire retardant and UV protection of pine wood. _Bioresour_ 13, 6963–6969 (2019). Article  Google Scholar  * Mallakpour, S. & Darvishzadeh, M.

Nanocomposite materials based on poly(vinyl chloride) and bovine serum albumin modified ZnO through ultrasonic irradiation as a green technique: optical, thermal, mechanical and

morphological properties. _Ultrason. Sonochem_. 41, 85–99 (2018). Article  CAS  PubMed  Google Scholar  * Faiza, Khattak, A., Alahmadi, A. A., Ishida, H. & Ullah, N. Improved PVC/ZnO

nanocomposite insulation for high voltage and high temperature applications. _Sci. Rep._ 13, 7235 (2023). Article  ADS  Google Scholar  * Naguib, H. M., Ahmed, M. A. & Abo-Shanab, Z. L.

Studying the loading impact of silane grafted Fe2O3 nanoparticles on mechanical characteristics of epoxy matrix. _Egypt. J. Pet._ 28, 27–34 (2019). Article  Google Scholar  * Wang, Y. W.,

Shen, R., Wang, Q. & Vasquez, Y. ZnO microstructures as Flame-Retardant coatings on cotton fabrics. _ACS Omega_. 3, 6330–6338 (2018). Article  CAS  PubMed  PubMed Central  Google Scholar

  * Deffo, G. et al. Eggshell nano-CaCO3 decorated PANi/rGO composite for sensitive determination of ascorbic acid, dopamine, and uric acid in human blood serum and urine. _Mater. Today

Commun._ 33, 104357 (2022). Article  CAS  Google Scholar  * Naguib, H. M. Recycled polyester filled with eggshells waste-based nano CaCO3: thermo-mechanical and flame-retardant features.

_New. J. Chem._ 47, 4999–5010 (2023). Article  CAS  Google Scholar  * Javed, A., Wiener, J., Saskova, J. & Müllerová, J. Zinc oxide nanoparticles (ZnO NPs) and N-Methylol dimethyl

Phosphonopropion amide (MDPA) system for flame retardant cotton fabrics. _Polymers_ 14, 3414 (2022). Article  CAS  PubMed  PubMed Central  Google Scholar  * Yi, L., Yang, Q., Yan, L. &

Wang, N. A facile strategy to construct ZnO nanoparticles reinforced transparent fire-retardant coatings for achieving antibacterial activity and long-term fire protection of wood

substrates. _J. Build. Eng._ 72, 106630 (2023). Article  Google Scholar  * Xu, B., Wu, M., Liu, Y. & Wei, S. Study on flame retardancy behavior of epoxy resin with phosphaphenanthrene

triazine compound and organic zinc complexes based on phosphonitrile. _Mol_ 28, 3069 (2023). Article  CAS  Google Scholar  * Nageswara Rao, T. et al. Influence of zinc oxide nanoparticles

and Char forming agent polymer on flame retardancy of intumescent flame retardant coatings. _Nanomater_ 10, 42 (2020). Article  Google Scholar  * Hajibeygi, M., Maleki, M., Shabanian, M.,

Ducos, F. & Vahabi, H. New Polyvinyl chloride (PVC) nanocomposite consisting of aromatic polyamide and Chitosan modified ZnO nanoparticles with enhanced thermal stability, low heat

release rate and improved mechanical properties. _Appl. Surf. Sci._ 439, 1163–1179 (2018). Article  ADS  CAS  Google Scholar  * Liu, Z. et al. Surface modification of zinc oxide and its

application in polypropylene with excellent fire performance and ultra-violet resistance. _J. Colloid Interface Sci._ 661, 307–316 (2024). Article  ADS  CAS  PubMed  Google Scholar  * Bajwa,

D. S., Shojaeiarani, J., Liaw, J. D. & Bajwa, S. G. Role of hybrid Nano-Zinc oxide and cellulose nanocrystals on the mechanical, thermal, and flammability properties of Poly (Lactic

Acid) polymer. _J. Compos. Sci._ 5, 43 (2021). Article  CAS  Google Scholar  * Chen, Y., Xu, L., Wu, X. & Xu, B. The influence of nano ZnO coated by phosphazene/triazine bi-group

molecular on the flame retardant property and mechanical property of intumescent flame retardant Poly (lactic acid) composites. _Thermochim Acta_. 679, 178336 (2019). Article  CAS  Google

Scholar  * Naguib, H. M. & Hou, G. Exploitation of natural and recycled biomass resources to get eco-friendly polymer. _J. Polym. Environ._ 31, 533–540 (2023). Article  CAS  Google

Scholar  * Zhu, J., Wang, X. & Chen, M. Low-density unsaturated polyester resin with the presence of dual-initiator. _Materials_ 16, 4677 (2023). Article  ADS  CAS  PubMed  PubMed

Central  Google Scholar  * Farsane, M. et al. Experimental evaluation of the curing of unsaturated polyester resin at various amounts of Methyl Ethyl ketone peroxide, Cobalt octoate and

porcelain powder. _Rev. Chim._ 71, 58–66 (2020). Article  CAS  Google Scholar  * Kfoury, G. et al. Tunable and durable toughening of polylactide materials via reactive extrusion. _Macromol.

Mater. Eng._ 299, 583–595 (2014). Article  CAS  Google Scholar  * Grimalt, J., Frattini, L., Carreras, P. & Fombuena, V. Optimizing rheological performance of unsaturated polyester resin

with bio-based reactive diluents: A comprehensive analysis of viscosity and thermomechanical properties. _Polym. Test._ 129, 108264 (2023). Article  CAS  Google Scholar  * Shimkin, A. A.

Methods for the determination of the gel time of polymer resins and Prepregs. _Russ J. Gen. Chem._ 86, 488–1493 (2016). Article  Google Scholar  * Gholami, A., Hajian, M., Rafiemanzelat, F.

& Zanjanijam, A. R. Plasticized poly(vinyl chloride) composites: influence of different nanofillers as antimigration agents. _J. Appl. Polym. Sci._ 132, 42559 (2015). Article  Google

Scholar  * Mohamed, M. R. et al. Surface activation of wood plastic composites (WPC) for enhanced adhesion with epoxy coating. _Mater. Perform. Charact._ 8, 22–40 (2019). Article  CAS 

Google Scholar  * El-Deeb, A. S., Taha, E. O., Kader, M. M. A., Naguib, H. M. & Hassaan, M. Y. Mechanical properties study of borosilicate glass loaded with vanadium and Cobalt by

nanoindentation technique. _Eng. Proc._ 31, 81 (2023). Google Scholar  * Takeoka, Y., Liu, S. & Asai, F. Improvement of mechanical properties of elastic materials by chemical methods.

_Sci. Technol. Adv. Mater._ 21, 817–832 (2020). Article  CAS  Google Scholar  * Xian, W., Zhan, Y. S., Maiti, A., Saab, A. P. & Li, Y. Filled elastomers: mechanistic and Physics-Driven

modeling and applications as smart materials. _Polymers_ 16, 1387 (2024). Article  CAS  PubMed  PubMed Central  Google Scholar  * Alnajjar, H. M. et al. Enhancement of recycled WPC with

epoxy nanocomposite coats. _Egypt. J. Chem._ 62, 555–563 (2019). Google Scholar  * Naguib, H. M. & Hou, G. Vinylester-glass fiber composite for water pipe: processing and effect of fiber

direction. _Egypt. J. Pet._ 32, 24–30 (2023). Article  Google Scholar  * Saba, N., Jawaid, M., Alothman, O. Y. & Paridah, M. T. A review on dynamic mechanical properties of natural

fibre reinforced polymer composites. _Constr. Build. Mater._ 106, 149–159 (2016). Article  CAS  Google Scholar  * Rajawasam, C. et al. Educational series: characterizing crosslinked polymer

networks. _Polym. Chem._ 15, 219–247 (2024). Article  CAS  Google Scholar  * Naguib, H. M., Ahmed, M. A. & Abo-Shanab, Z. L. Silane coupling agent for enhanced epoxy-iron oxide

nanocomposite. _J. Mater. Res. Technol._ 7, 21–28 (2018). Article  CAS  Google Scholar  * Mat Yazik, M. H. et al. N.A. Effect of nanofiller content on dynamic mechanical and thermal

properties of multi-walled carbon nanotube and montmorillonite nanoclay filler hybrid shape memory epoxy composites. _Polymers_ 13, 700 (2021). Article  PubMed  PubMed Central  Google

Scholar  * Ponnamma, D. et al. Synthesis, optimization and applications of ZnO/polymer nanocomposites. _Mater. Sci. Eng. C_. 98, 1210–1240 (2019). Article  CAS  Google Scholar  * Raha, S.

& Ahmaruzzaman Md. ZnO nanostructured materials and their potential applications: progress, challenges and perspectives. _Nanoscale Adv._ 4, 1868–1925 (2022). Article  ADS  CAS  PubMed 

PubMed Central  Google Scholar  * Hurtado-Alonso, N., Manso-Morato, J., Revilla-Cuesta, V., Skaf, M. & Ortega-López, V. Optimization of cementitious mixes through response surface

method: a systematic review. _Arch. Civ. Mech. Eng._ 25, 54 (2025). Article  Google Scholar  * Srinivasa, A. S., Swaminathan, K. & Yaragal, S. C. Microstructural and optimization studies

on novel one-part geopolymer pastes by Box-Behnken response surface design method. _Case Stud. Constr. Mater._ 18, e01946 (2023). Google Scholar  Download references FUNDING Open access

funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB). AUTHOR INFORMATION AUTHORS AND AFFILIATIONS *

Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo, 11727, Egypt Hamdy M. Naguib Authors * Hamdy M. Naguib View author publications You can

also search for this author inPubMed Google Scholar CONTRIBUTIONS The manuscript was written through the contributions of authors. All authors have approved the final version of the

manuscript. CORRESPONDING AUTHOR Correspondence to Hamdy M. Naguib. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. ADDITIONAL INFORMATION PUBLISHER’S

NOTE Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. RIGHTS AND PERMISSIONS OPEN ACCESS This article is licensed under

a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate

credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article

are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons

licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of

this licence, visit http://creativecommons.org/licenses/by/4.0/. Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Naguib, H.M. Impact of Tung oil on a sustainable bio-based

polymer, and development by zinc oxide nanoparticles. _Sci Rep_ 15, 18353 (2025). https://doi.org/10.1038/s41598-025-99556-x Download citation * Received: 06 December 2024 * Accepted: 21

April 2025 * Published: 26 May 2025 * DOI: https://doi.org/10.1038/s41598-025-99556-x SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get

shareable link Sorry, a shareable link is not currently available for this article. Copy to clipboard Provided by the Springer Nature SharedIt content-sharing initiative KEYWORDS * Tung oil

* Polyester * Solid waste * Zinc oxide nanoparticles