氯化专用聚氯乙烯树脂颗粒特性的研究——非离子型表面活性剂和链转移剂的影响

The Particle Characters of Polyvinyl Chloride Resin for Chlorination: Influences of Non-ionic Surfactant and Chain Transfer Agent

水相悬浮法生产氯化聚氯乙烯(CPVC)时,氯化速度和氯化均匀性取决于Cl2在聚氯乙烯(PVC)颗粒中的扩散程度,因而需要有能满足氯化要求的PVC专用树脂。采用以聚乙烯醇(PVA)和羟丙基甲基纤维素(HPMC)为主的复合分散剂,考察Span系列非离子表面活性剂、链转移剂等对PVC颗粒特性的影响。实验结果表明,表面活性剂的加入使PVC树脂增塑剂吸收率、平均粒径和比表面积增大,粒径分布变窄,而表观密度下降;随着链转移剂的加入,PVC树脂增塑剂吸收率、平均粒径和表观密度都增加。

The chlorinated polyvinyl chloride （CPVC） resin was usually prepared by aqueous chlorination of polyvinyl chloride （PVC） resin and the diffusion of Cl2 in PVC particles had significant influences on the chlorination rate and uniformity, thus, special PVC resin was expected for chlorination. The influences of non-ionic surfactants and chain transfer agent on particle characters of the polyvinyl chloride resin were investigated by taking polyvinyl alcohol （PVA） and hydroxypropyl methyl cellulos （HMPC） as the main dispersant. The experimental results showed that the cold plasticizer absorption, specific surface area and average particle size all increased when Span series non-ionic surfactants were added, while the particle size distribution became narrow and the apparent density decreased. As the concentration of chain transfer agent increased, the cold plasticizer absorption, average particle size and apparent density all increased, while the degree of polymerization decreased.