肼基封端聚氨酯乳液的制备及其对丙烯酸酯共聚物乳液粘合剂的改性  

Preparation and study of hydrazine-terminated polyurethane emulsions for modifying polyacrylic-copolymer latex adhesives

作　　者：夏宇正[1] 陈一岭[1] 石淑先[1] 焦书科[1] 

机构地区：[1]北京化工大学碳纤维及功能高分子教育部重点实验室,北京100029

出　　处：《北京化工大学学报（自然科学版）》2009年第6期66-71,共6页Journal of Beijing University of Chemical Technology(Natural Science Edition)

摘　　要：以聚酯二元醇、甲苯二异氰酸酯、二羟甲基丙酸(DMPA)、水合肼等为原料,制得了自乳化的肼基封端聚氨酯稳定乳液。以苯乙烯、丙烯酸乙酯、丙烯酸异辛酯、丙烯酸和双丙酮丙烯酰胺为单体,通过乳液聚合制得了含酮羰基丙烯酸酯共聚物乳液。将含肼基和酮羰基的两种乳液共混,所得复合乳液用作塑-塑复合粘合剂,使其在室温下发生酮肼交联反应以提高粘接性能。考察了预聚反应时间对预聚反应程度、不同DMPA含量和R值(预聚体中n(—NCO)/n(—OH))对聚氨酯乳液性能以及两种乳液配比对胶膜凝胶含量、吸水率及180°剥离强度的影响,并比较了含肼基聚氨酯和小分子己二酰肼对丙烯酸酯共聚物乳液的改性效果。结果表明:当预聚反应210 min、DM-PA质量分数4.5%、R值小于1.5时,可制得稳定的聚氨酯乳液;随着共混乳液中肼基含量的增加,乳胶膜凝胶含量增大,吸水率增加,180°剥离强度降低;含肼基的聚氨酯对丙烯酸酯共聚物乳液的改性效果优于小分子己二酰肼的改性。Stable hydrazine-terminated polyurethane emulsions have been prepared using toluene diisocyanate, polyester diol, dimethylol propanic acid （DMPA） and hydrazine hydrate as raw materials. A polyacrylic latex incorporating ketone groups was synthesized by emulsion polymerization using styrene, ethyl acrylate and iso-octyl acrylate as the main monomers, and acrylic acid and diacetone acrylamide as functional monomers. The reaction between the hydrazine and ketone groups in a composite polyurethane/polyacrylic emulsion occurs at room temperature and improves the adhesion properties on a plastic-plastic interface. The effects of varying reaction time on the content of the isocyanate group in the polyurethane prepolymer, and the amount of DMPA and the isocyanate index on the properties of the polyurethane emulsion were studied in detail. Gel content, water absorption rate and 180° peel strength of the polyurethane/polyacrylic composite films were measured. The results showed that stable polyurethane emulsions could be prepared when the prepolymerization time was 210 min, the content of DMPA was 4.5 %, and the isocyanate index was less than 1.5. The gel content and water absorption rate of the films increased and 180° peel strength decreased when the hydrazine content in the composite emulsion was increased. The properties of the polyurethane/acrylate copolymer emulsion are superior to those of adipic dihydrazide.

关 键 词：聚氨酯乳液 丙烯酸酯乳液 肼基 酮羰基 改性 

分 类 号：TQ323.8[化学工程—合成树脂塑料工业]