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

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.