PMMA/CaCO_3/SiO_2三元复合粒子的制备及控制

PREPARATION AND CONTROLLING OF POLY(METHYL METHACRYLATE/CaCO_3/SiO_2 THREE-COMPONENT COMPOSITE PARTICLES

采用反相原子转移自由基聚合法合成了PMM A/C aCO3/S iO2三元复合粒子,探讨了不同配体对聚合可控性的影响。结果表明,胺类配体比联吡啶类配体更容易实现对改性C aCO3/S iO2二元无机复合粒子存在下甲基丙烯酸甲酯(MM A)自由基聚合的控制。通过红外光谱和热失重分析,进一步表明聚甲基丙烯酸甲酯(PMM A)和C aCO3/S iO2无机复合粒子间通过强相互作用(共价键)结合。利用所得PMM A/C aCO3/S iO2三元复合粒子作为大分子引发剂可进一步引发MM A的原子转移自由基聚合,PMM A的数均分子量由聚合前的23400升高到聚合后的29400,反应具有明显的活性特征。

The attempt to prepare structurally well-de[ined polymer/inorganic composite particles, i.e. poly （methyl methacrylate）/CaCO3/SiO2 three composite particles, via reverse atom transfer radical polymerization, using AIBN as initiator and Cu （Ⅱ） bromide as catalyst was reported. The effect of different ligants on the polymerization was studied and the results indicate that TMEDA is the best ligant for the controlling of the polymerization system. Characterizations of the PMMA-grafted CaCO3/SiO2 composite particles were done by FT-IR and thermogravimetric analysis. The results show that the surface of the modified inorganic particles is grafted by the MMA and that the grafting percentage is about 9.2%. PMMA/CaCO3/SiO2 three composite particles obtained were used as macro-initiator to process chain-extension reaction via a conventional ATRP process. After extension, the molecule weight of PMMA increases from 23400 to 29400, which represents the characteristics of ‘living＇/controlled polymerization.