Abstract:

Radiation induced emulsion polymerization is one method that in high-energy rays the medium is decomposed into free radicals triggering emulsion polymerization. In this paper，a double bond terminated polyurethane prepolymer was synthesized with DMPA，N210，HPMA and IPDI，as raw materials．The obtained prepolymer was then mixed with MMA and BA to decrease its viscosity. Polyurethane-acrylate（PUA）could be obtained through mechanical emulsification，neutralization and copolymerization with MMA and BA by ⁶⁰Co radiation（initiator）. Casting film of PUA was characterized with FTIR，TGA，mechanical properties and water resistance tests．The results showed that the properties of PUA prepared through radiation induced emulsion polymerization were superior to that prepared with chemical initiator polymerization. Compared with the chemical method，the average particle size was decreased from 143.5 nm to 100 nm；solid content was increased from 37.5% to 38.6%；tensile strength was increased from 15.3 MPa to 18.3 MPa；water absorption rate of casting film was decreased from 7.4% to 5.6%；and initial thermal decomposition was increased from 320 ℃ to 380 ℃．The findings could provide guidance for the synthesis of PUA and related research．

摘要：

辐射乳液聚合是一种在高能射线辐照下使介质分解成自由基而引发乳液聚合的方法。作者以二羟甲基丙酸（DMPA）、聚醚二元醇（N-220）、甲基丙烯酸-β-羟丙酯（HPMA）和异佛尔酮二异氰酸酯（IPDI）等为原料合成碳-碳双键封端的水性聚氨酯预聚物，用丙烯酸酯丁酯（BA）和甲基丙烯酸甲酯（MMA）混合单体降低体系黏度。经过机械乳化、中和、钴60γ-射线辐射聚合，制得了水性聚氨酯-丙烯酸酯（PUA）复合乳液。用红外光谱（FTIR）、粒径分析、热重分析（TGA）等对乳液粒子和膜性能进行了分析和表征。结果表明，与化学聚合法相比，辐射聚合法有明显的优势，乳液平均粒径由143.5 nm降至100 nm，乳液固含量由37.5%提高至38.6%；膜的拉伸强度由15.3 MPa提升至18.3 MPa，膜的吸水率由7.4%降至5.6%，热分解温度由320 ℃升高到380 ℃。所得结果对水性聚氨酯-丙烯酸复合乳液的合成及相关研究具有一定的指导意义。