高分子量聚醋酸乙烯酯乳液和醋酸乙烯酯-乙烯共聚物乳液的合成及力学性能  

Synthesis and Mechanical Property of High Molecular Weight Polyvinyl Acetate and Vinyl Acetate-Ethylene Copolymer Emulsions

作　　者：肖长发 Changfa Xiao(R&D Center,Sinopec Chongqing SVW Chemical Co.,LTD,Chongqing SVW Technology Co.,LTD,Chongqing 401254,China)

机构地区：[1]中国石化集团重庆川维化工有限公司研发中心、重庆川维科技有限公司,重庆401254

出　　处：《高分子材料科学与工程》2023年第1期35-42,共8页Polymer Materials Science & Engineering

摘　　要：对比研究了保护胶体聚乙烯醇(PVA)、阴离子乳化剂十二烷基硫酸钠(SDS)加料量和引发剂加料速率对聚醋酸乙烯酯(PVAc)和醋酸乙烯酯-乙烯共聚物(VAE)乳液聚合过程中乳胶粒粒径和相对分子质量演化的影响。乳胶粒成核后明显的团聚特性决定了增加保护胶体PVA和阴离子乳化剂SDS加料量对提高PVAc相对分子质量作用不明显。该聚合体系中由于成核乳胶粒强烈的团聚倾向,同一乳胶粒中可同时存在多个自由基,减小引发剂加料速率可降低双基终止几率,明显提高PVAc相对分子质量。进一步利用该技术合成了不同相对分子质量的VAE乳液,力学性能对比测试表明,高分子量VAE乳液成膜具有更优异的力学性能,在聚合物水泥防水复合材料领域具有明显的性能优势。The effects of polyvinyl alcohol(PVA),anionic emulsifier sodium dodecyl sulfate(SDS)and initiator feeding rates on particle sizes and molecular weight evolutions of polyvinyl acetate(PVAc)and vinyl acetate-ethylene copolymer(VAE)emulsions were comparatively studied in polymerization processes.The obvious agglomeration characteristics along with nucleation determines that adding amounts of protective colloid PVA and anionic emulsifier SDS has no obvious effect on increasing molecular weight of PVAc.Owing to the dramatic agglomeration tendency of nucleated latex particles,multiple free radicals could exist in the same latex particle at the same time.Reducing the initiator feeding rates reduces the probability of bi-radical termination in the particles,which significantly increases the molecular weight of PVAc.VAE emulsions with different molecular weights were further synthesized by this method.The mechanical comparison tests show that the VAE film with high molecular weight has better mechanical properties and obvious performance advantages in manufacturing polymer and cement waterproof composite materials.

关 键 词：醋酸乙烯酯-乙烯 乳液 相对分子质量 

分 类 号：TQ316.334[化学工程—高聚物工业]