Epoxy soybean oil plasticized vinyl chloride acrylate waterborne emulsion: Physically mixed versus chemically grafted

In this study, two types of epoxy soybean oil (ESO) modified vinyl chloride acrylate copolymer emulsion (vc-m), that is, physically modified vc-m-1 and chemically grafted vc-m-2, were well prepared initially. The chemical structure, particle size distribution, surface morphology, flexibility, and mechanical properties of the three emulsions were studied through Fourier transform infrared analysis, proton nuclear magnetic resonance analysis, nano-size analysis, atomic force microscopy, dynamic mechanical analysis, as well as tensile test. Compared with vc-m, the glass transition temperature (T-g) of vc-m-1 and vc-m-2 was reduced by nearly 28%, the tensile strength was increased by 50%, and the elongation at break was improved by 70.5% and 70.7%, respectively. No significant difference was identified between vc-m-1 and vc-m-2. Furthermore, the chemical reaction mechanism and internal plasticizing mechanism of vc-m-2 synthesis were discussed. ESO enhanced the low-temperature brittleness and mechanical strength of the emulsion, and vc-m-2 exhibited better migration stability while maintaining the identical flexibility and mechanical properties as vc-m-1. The modified emulsion is capable of adapting to low ambient temperatures when applied to coatings and road adhesives while showing promising applications.