Effect of CaSt(2)/ESO thermal stabilizers on the preparation, thermal stability, and thermal stability mechanism of self-made vinylidene chloride-methyl acrylate copolymer resin film

The effects of heat stabilizer systems on the thermal stability and processability of self-made vinylidene chloride-methyl acrylate copolymer (PVDC-MA) film were investigated via accelerated aging test, Congo red test, FTIR, DMA, and TG-FTIR. These results displayed that CaSt(2)/ESO performed excellently in synergistic inhibition of PVDC-MA thermal degradation. Especially, when the mass ratio of CaSt(2)/ESO was 1.5:1.5, the static thermal stability time of PVDC-MA was increased from 14.5 to 46.5 min. The kinetic calculation results also verified this point. Compared with pure PVDC-MA, the average apparent activation energy (E-a) of thermal degradation reaction of PVDC-MA stabilized by CaSt(2)/ESO enhanced from 144.1 to 169.7 kJ mol(-1) (alpha(0) <= 0.1), indicating that the thermal stability of PVDC-MA in the initial thermal degradation stage was dramatically improved by CaSt(2)/ESO. Moreover, the mechanism of the effect of CaSt(2)/ESO on PVDC-MA in the initial thermal degradation stage was further explored by the generalized master plot methods. The kinetic analysis result suggested that under the synergistic effect of CaSt(2)/ESO, the mechanism model followed by the degradation of PVDC-MA changed essentially (the three-dimensional diffusion thermal degradation mechanism transformed into two-dimensional diffusion).