硬质聚氯乙烯用复合发泡剂的研究

Study of the composite foaming agent for rigid polyvinyl chloride

采用活化剂(尿素、碳酸锌)和碳酸氢钠对偶氮二甲酰胺(AC)改性制备硬质聚氯乙烯(R-PVC)用复合发泡剂,并用热分析和放气量检测对复合发泡剂进行了表征。结果表明当AC、NaHCO3、尿素和碳酸锌的质量比为10:10:2.5:2.5时所得的复合发泡剂分解温度处于R-PVC成型加工范围内,吸-放热基本平衡,放气量大且无突发性。采用这种复合发泡剂制备的硬质聚氯乙烯发泡材料具有较好的力学性能和微孔结构。

A novel kind of composite foaming agents for rigid PVC（R-PVC） was prepared from modifying azodicarbonamide（AC） with kickers（carbamide,zinc carbonate） and sodium bicarbonate.The samples were analyzed with thermal analysis and gas volume test.The results indicate that the novel composite foaming agent with a mass ratio of 10∶10∶2.5∶2.5,which represent AC,carbamide,zinc carbonate and sodium bicarbonate respectively,poses optimized properties： its decomposition temperature lies within the temperature range suitable for R-PVC processing,its endotherm equals exotherm on the whole and this composite foaming agent has a high volume of liberated gas but without any abruptness.R-PVC foam manufactured with this composite foaming agent has better mechanical properties,and its SEM images present fine microcellular structure.