凝胶原位聚合制备P(MMA-co-St)/RE(OPri)_3复合材料的研究

Composites of P(MMA-co-St)/RE(OPri)_3 Prepared by Gel In-Situ Polymerization

在氮气保护下,将三异丙氧基稀土(RE(OPri) 3,RE为铕、铽、钐、镝)直接掺杂到含0 1% (质量分数)AIBN的甲基丙烯酸甲酯(MMA)和苯乙烯(St)混合单体,形成凝胶后,在一定温度下原位聚合制备了P(MMA co St) /RE(OPri) 3复合材料,用动态机械热分析(DMTA)、热重分析(TG)、荧光分析(FS)和环境扫描电镜(ESEM )对其进行表征。结果表明,与P(MMA co St)相比,P(MMA co St) /RE(OPri) 3的性质和微观形貌均有较大的变化。掺稀土后,共聚物的玻璃化转变温度大多稍有下降,但玻璃化前后的贮能模量、耐热性能均有不同程度的提高,动态力学曲线呈现出类似交联结构的特征,同时其微观形貌也呈现交联网络结构;FS表明,P(MMA co St)中的羰基与稀土离子的配位,导致其特征荧光红移,同时掺铕、铽的共聚物呈现铕、铽稀土离子特征荧光。

Composites of P(MMA-co-St)/RE(OPri)_3 (RE: Eu, Tb, Sm or Dy) were prepared by the in-situ polymerization of gel, which was obtained by doping directly triisopropoxyl rare earth in the monomer mixtures of methyl methacrylate and styrene (monomer mole ratio was 1∶1) in the protection of N_2 atmosphere. The composites were characterized by dynamical mechanical thermal analysis (DMTA), TG, fluorescence spectra (FS), ESEM etc. Compared to pure P(MMA-co-St), the properties and microscopic morphology of the composites change obviously. The glass transition temperature (T_g) of P(MMA-co-St) is reduced by the doping of triisopropoxyl rare earth, while the storage modulus (E′) and heat resistance of the copolymer are improved. Dynamical mechanical curves reveal the crosslinking network structure of composites. There are coordination interactions between rare earth ions and carboxyl or phenyl group in the P(MMA-co-St)/RE(OPr i)_3 and result in the characteristic red shift in luminescence spectrum. Moreover, the composites doped with mixed Eu or Tb emit Eu or Tb ion characteristic luminescence.