核壳结构的有机硅改性苯丙乳液的制备

Preparation of silicone modified styrene acrylic emulsion with core-shell structure

以苯乙烯(St)、甲基丙烯酸甲酯(MMA)、丙烯酸异辛酯(EHA)、丙烯酸丁酯(BA)、丙烯酸(AA)为主要单体,以3-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)为有机硅单体,以十二烷基硫酸钠(SDS)、壬基酚聚氧乙烯醚(OP-10)为混合乳化剂,且二者的质量比为SDS∶OP-10=9∶2,以过硫酸钾(KPS)为引发剂,采用梯度升温法,制备了具有核壳结构的有机硅改性苯丙乳液,确定其最佳工艺条件为:混合乳化剂的量为单体总量的3%、硬软单体比例为5∶3、KH560最佳添加量为4.5%。与单体组成相同的非核壳结构的有机硅改性苯丙乳液相比,核壳乳液膜的性能优于非核壳乳液膜,核壳乳液的最低成膜温度降低约10℃左右,红外分析二者成膜时聚合产物一样,热重分析表明核壳结构的有机硅改性苯丙乳液膜的耐热性可提高10℃。

The main monomers of the emulsion were styrene(St),methyl methacrylate(MAA),2-ethylhexyl acrylate(EHA),n-butyl acrylate(BA)and acrylic acid(AA).3-(2,3-epoxy propoxy)propyltrimethoxysilane(KH560)was added as silicone monomer.Sodium dodecyl sulfate(SDS)and nonylphenol polyoxyethylene ether(OP-10)were used as mixed emulsifier at the rate of 9∶2 in mass.With potassium persulfate(KPS)as initiator,the silicone modified styrene acrylic emulsion with core-shell structure was prepared by gradient elevation of temperature.The optimum technological conditions were as follows:the amount of mixed emulsifier was as 3%of the total monomer,the proportion of hard/soft monomer was 5∶3,and the optimum dosage of KH560 was 4.5%.Compared with the silicone modified styrene acrylic emulsion with the Noncore-shell structure compared with the same monomer,the core shell emulsion film has better performance than the noncore-shell emulsion film.The minimum film forming temperature of the core shell emulsion is decreased about 10℃.The infrared analysis shows that the polymerization products produced by the two infrared forming methods are the same.Thermogravimetric analysis shows that the heat resistance of the silicone modified styrene acrylic emulsion film with core shell structure can be increased by 10℃.