SiO_2改性热交联型丙烯酸酯乳液的合成及性能

Preparation and Properties of Thermal Cross-linking Acrylic Emulsion Modified by SiO_2 via In-situ Polymerization

将阴离子型乳化剂和非离子型乳化剂复配为乳化体系,以过硫酸铵(APS)为引发剂,使用有机硅KH-560对纳米SiO2进行表面接枝改性,并与丙烯酸酯单体进行原位共聚制备种子乳液。在壳层预乳液中添加活性交联单体丙烯酸(AA)和丙烯酸羟乙酯(HEA),采用预乳化半连续种子乳液聚合工艺制备热交联型丙烯酸酯乳液。考察了乳化剂配比和纳米SiO2用量对涂膜耐水性和耐热性能的影响,利用透射电镜(TEM)和傅立叶红外光谱(FTIR)对乳液的形态、粒径分布及组成进行了表征。结果表明,乳液粒子具有明显的核壳结构特征;通过加入氨基树脂配成热交联涂料,涂膜的热稳定性、耐水性和硬度均得到了明显提高。阴离子、非离子乳化剂质量比为1∶3,HEA和纳米SiO2质量分数分别为成膜物质的11.0%和9.97%时,得到的热交联型丙烯酸酯乳液性能较佳。

Thermal cross-linking acrylic emulsion was prepared by pre-emulsifying semi-continuous seed emulsion polymerization process using mixed anionic and nonionic emulsifier and ammonium persulfate（APS） initiator.In the process,seed emulsion was synthesized with nano-SiO2 graft modified by silicone KH-560 and acrylic ester monomers via in-situ polymerization,and then active cross-linked monomer acrylic acid（AA） and hydroxy ethyl acrylate（HEA） were introduced to shell pre-emulsion.The influence of emulsifier ratio and nano-SiO2 amount on the water resistance and heat resistance of film was studied.The particle morphology,particle size distribution and composition of the emulsion were characterized by transmission electron microscopy（TEM） and fourier transform infrared spectroscopy（FTIR）.The results indicate that emulsion latex particles had obvious core-shell structure.Thermal cross-linking coating was prepared by adding amino resin,and the thermal stability,water resistance and hardness of the coating were further improved.The optimum performance of thermal cross-linking emulsion was obtained under the conditions： emulsifier A and B ratio was 1∶3,the addition amount of HEA and nano-SiO2 were 11.00 and 9.97 percent of film-forming materials,respectively.