Rheological properties and dynamic thermal stability ofPVC/La L2/Ca‐Zncomposite stabilizer

Abstract

AbstractLanthanum complex with curcumin (La L2)/Ca‐Zn composite stabilizer was prepared using La L2and 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 L2/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 L2had an effective synergistic effect with Ca‐Zn stabilizer. Compared with La L2, La L2/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 L2with 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 L2/Ca‐Zn composite stabilizer for PVC was suggested based on the evaluation of FTIR spectroscopy and UV‐vis spectroscopy.