无机添加剂对氯乙烯悬浮聚合的影响

Effects of inorganic additives on suspension polymerization process of vinyl chloride

研究了添加未改性和表面改性的无机热稳定剂和CaCO3对氯乙烯悬浮聚合过程的影响,发现采用硅烷和铝酸酯改性无机热稳定剂和采用硬脂酸改性CaCO3,可以达到良好的表面有机改性效果,改性剂最佳质量分数为1.0%左右;热稳定剂对聚合起延缓作用,使一定压降(△P)时的聚合时间增加5～120 min、转化率下降3.6%～17.5%;但经表面改性后,对聚合的延缓作用减弱;CaCO3使聚合△P提前10～20min,使一定△P时的聚合转化率下降2.4%～17.5%,但对实际聚合速率的影响不大.

This paper studied the influences of inorganic thermal stabilizer with or without surface modification and calcium carbonate (CaCO3) on the suspension polymerization process of vinyl chloride. It is found out that high effectiveness of surface organic modification can be achieved via modification of the inorganic thermal stabilizers with silane and aluminates and modification of CaCO3 with stearic acid. The optimum mass fraction of the modifier is about 1.0%. Thermal stabilizer usually plays a function of retarding polymerization, thereby increasing polymerization time by 5-120 minutes at a given pressure drop (△P) and lowering conversion by 3.6%-17.5%. However, after the thermal stabilizer is subject to surface modification, its function of retarding polymerization is weakened. The presence of CaCO3 as filler leads to an early occurrence of △P by shorting 10-20 minutes and lowers polymerization conversion by 2.4%-17.5% at a given AP, but brings about little impact on the practical polymerization rate.