Abstract: The thermal stabilizing effect of curcumin on PVC was studied by Congo red testing and FTIR and compared with commercial lead salt and Ca/Zn compound stabilizers. Rheological performance and mechanical property of PVC constaining these stabilizers were studied. It was found that the static thermal stability was 14 min when 3 part curcumin was used. FTIR indicated that curcumin could reduce the oxidatized degradation of PVC. Curcumin had obvious synergistic effect with lanthanum lauric and calcium stearate. Static and dynamic thermal stable time could reach 50 min and 47 min with ratios of curcumin: lanthanum lauric:calcium stearate eqoal 1:0.8:0.5. Rheological and mechanical properties were similar to those of lead salt, better than those of Ca/Zn compound stabilizer. Dynamic thermal stability time was significantly longer than that of the lead and Ca/Zn containing systems.

Key words: poly(vinyl chloride), curcumin, thermal stabilizer, rare earths, calcium stearate