摘要
采用偶氮二异丁腈(AIBN)为引发剂,阴离子聚氨酯水分散体(PUD)为乳化剂和反应物,与甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)通过乳液共聚合制备高固体含量聚氨酯丙烯酸酯复合乳液(PUA)。研究提高PUA乳液固体含量的途径,讨论单体种类和添加量对PUA乳液与涂膜性能的影响,并采用热重分析(TGA)和傅里叶红外光谱(FT-IR)对PUA涂膜的热稳定性和结构进行表征。研究结果表明:将PUD/丙烯酸酯单体以6000r/min的转速分散20min,在70℃热聚合1～2h,后期追加单体质量分数为0.70%的AIBN能提高PUA乳液的固体含量达45%以上;在m(PUD)/m(单体)=1:1.2,m(MMA)/m(BA)=2:1条件下合成的PUA涂膜拥优异涂膜性能:涂膜的吸水率为15.5%,吸碱率为7.9%,吸醇率为28.9%,摆杆硬度为0.75和耐低温冷脆性(-20℃,3d,涂膜不开裂);MMA与BA复合能明显提高PUA涂膜热稳定性。
High solid contents waterborne polyurethane-acrylate hybrid emulsions （PUA） were synthesized by emulsion copolymerization of aqueous polyurethane dispersion （PUD） and acrylic monomers including methyl methacrylate （MMA） and butylacrylate （BA） in the present of azodiisobutyronitrile （AIBN） using PUD as an emulsifier and a reactant. The preparation methods of high solid contents emulsions were investigated. The effects of monomer categories and contents on the PUA properties were studied. Meantime, the structures and properties of PUA were characterized by FTIR spectra and thermal gravimetric analysis （TGA）. The results show that PUA emulsions with high solid contents up to 45% are obtained when PUD/monomers are dispersed at 6 000 r/min rotation speed for 20 min and thermal polymerized at 70 ℃ for 1：2 h and 0.70% AIBN is added as a post-addition initiator. PUA films display good performance including 15.5% water absorption, 6.9% alkali absorption, 22.6% ethanol absorption, 0.75 hardness, and good low temperature crack-resistance （-20 ℃, 72 h, film surface no crack） when the mass ratio of PUD/ monomers and MMA/BA are 1：1.2 and 2：1, respectively. The PUA films containing MMA and BA display good thermal stability.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第1期90-96,共7页
Journal of Central South University:Science and Technology
基金
粤港关键领域重点突破项目(TC04B494-4)
关键词
聚氨酯丙烯酸杂合乳液
高固含量
耐水性
polyurethane-acrylate hybrid emulsion
high solid content
water-resistance
