摘要
采用半连续无皂乳液聚合方法在未经硅烷偶联剂改性的230 nm亲水性SiO2微球表面聚合甲基丙烯酸甲酯(PMMA)壳层,制备以SiO2粒子为核、PMMA为壳层的复合胶体微球。研究微球表面形貌、组成、粒径变化规律,探索聚合反应的成核过程和PMMA进料流量对复合微球粒径的影响。结果表明,在未经硅烷偶联剂改性的纳米SiO2表面可形成稳定规整的PMMA壳层,SiO2/PMMA复合胶体微球球型度接近1.0,单分散性较好,多分散度指数(PDI)小于0.04。聚合反应受甲基丙烯酸甲酯(PMMA)单体含量控制,随着PMMA进料流量增加,乳胶粒子成核过程由均相成核过渡为胶束成核,复合微球粒径加速增大,多分散性增强,其粒径可通过调节PMMA进料流量控制。
The SiO2/PMMA composite colloid microspheres were generated by a semi-continuous soapfree emulsion polymerization technique using the hydrophilic SiO 2 microspheres with uniform size （230 nm） without silane coupling agents. The composite microspheres were prepared by polymethylmethacrylate （PM- MA） as the shell and SiO 2 as the core. The nucleation mechanism and the influences of the flux of PMMA monomer on the particle size were investigated by the surface micro-topography, composition and the change discipline of the particle size during the nucleation process. The results indicated that the regular and stable PMMA shells can be coated on the surface of SiO 2 nanoparticles without modifying by the silane coupling agents. The mono-dispersed SiO2/PMMA composite colloid microspheres were synthesized with the sphericity of near 1.0 and PDI 〈 0. 04 and monodispersed well. The nucleation mechanisms determined by the molar fraction of PMMA transited from homogenous nucleation to micellar nucleation. The particle size rapidly grew and the dispersibility decreased as the increase of the flux of PMMA. The diameters of SiO 2/PMMA microspheres can be determined by the flux of PMMA.
出处
《塑料工业》
CAS
CSCD
北大核心
2011年第10期30-33,37,共5页
China Plastics Industry
基金
山东省泰山学者工程资助
中国石油大学(华东)引进人才博士基金项目(y0904046)
关键词
无皂乳液聚合
甲基丙烯酸甲酯
复合胶体微球
粒径可控
成核过程
Soap-free Emulsion Polymerization
PMMA
Composite Colloid Microspheres
Controlled Diameter
Nucleation Process
