一种硬质PVC用复合发泡剂的制备及热性能研究

用碳酸氢钠（NaHCO3）、偶氮二甲酰胺（AC）及硬脂酸铅（PbSt）为原料制备吸放热复合发泡剂,通过差热与热重分析研究了发泡剂的热分解性能。结果表明：NaHCO3与AC之质量比为100∶20的发泡剂分解温度在170～188℃之间,且分解平稳,适合硬质PVC发泡材料加工。PbSt含量超过10%会影响发泡剂的分解率。用自制的吸-放热复合发泡剂用于硬质PVC挤出制备发泡材料,其密度可达约0.8g/cm3,且发泡材料泡孔细密均匀。

Preparation and Thermal Properties of Decalescence-Exothermic Composite Foaming Agent for Rigid PVC Foam

The composite foaming agent for rigid PVC foam which composed of azodimethylamide （AC）, sodium bicarbonate （NaHCO3） and lead stearate （PbSt） has been prepared. The thermal decomposition of the foaming agent has been determined with differential thermal analysis （DTA） and thermo gravimetric analysis （TGA）, and the results have showed that when the decomposition temperature of composite foaming agent composed of NaHCO3 and azodimethylamide（AC） with the content ratio 100：20 can decompose reposefully between 170 ℃ and 188 ℃. The rigid PVC foam preparation had been done with the decalescence-exothermic composite foaming agent, PVC and another materials. The rigid PVC foam has fine and well-proportioned pores and the density is approximately 0.8 g/cm^3. These results showed that the decalescence-exothermic composite foam is good for rigid PVC foam material preparation.