Rheological properties and dynamic thermal stability of PVC/La L2/Ca-Zn composite stabilizer

Lanthanum complex with curcumin (La L 2 )/Ca-Zn composite stabilizer was prepared using La L 2 and Ca-Zn stabilizer, in which Ca-Zn stabilizer was obtained from calcium stearate and zinc stearate at their mass ratio of 5:1. The rheological properties and dynamic thermal stability of polyvinyl chloride (PVC) stabilized by La L 2 /Ca-Zn composite stabilizers were estimated through a torque rheometer. The degraded fragments obtained from the torque experiments were measured by Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-vis) spectroscopy. La L 2 had an effective synergistic effect with Ca-Zn stabilizer. Compared with La L 2 , La L 2 /Ca-Zn composite stabilizer could more significantly improve the rheological properties and dynamic thermal stability of PVC. An optimal synergistic effect could be observed when the mass ratio of La L 2 with Ca-Zn stabilizer was about 8:2, in which the plasticizing torque and equilibrium torque of PVC was 33.3 N m and 22.5 N m, respectively, and its dynamic thermal stabilizing time was 25.1 min. The possible thermal stability mechanism of La L 2 /Ca-Zn composite stabilizer for PVC was suggested based on the evaluation of FTIR spectroscopy and UV-vis spectroscopy.