甲基丙烯酸2,2,2-三氟乙酯的原子转移自由基聚合

以α-溴代丙酸乙酯(EPN-B)/CuCl/ 联二吡啶(bpy)作为引发/催化体系、环己酮为溶剂,对甲基丙烯酸2,2,2-三氟乙酯(TFEMA)进行原子转移自由基聚合(ATRP),研究了TFEMA的反应动力学,并考察了引发/催化体系、引发剂EPN-B用量、配位剂bpy用量及单体配比对聚合反应的影响.结果表明,采用EPN-B/CuCl/bpy引发/催化体系对TFEMA进行ATRP,可得到窄分子量分布的聚甲基丙烯酸2,2,2-三氟乙酯(PTFEMA),在实验范围内,聚合速率对单体浓度呈一级动力学关系,该反应过程具有活性聚合特征;随着引发剂EPN-B和配位剂bpy用量的增加,聚合速率加快,当EPN-B相对摩尔用量为0.5,1.0,2.0时,其相应的表观链增长速率常数分别为3.143×10~(-4),3.478×10~(-4),4.435×10~(-4)s~(-1);增大TFEMA]/EPN-B](摩尔比),聚合速率明显降低,但无论TFEMA]/EPN-B]高与低,聚合物的分布指数均为1.15～1.23.

Atom transfer radical polymerization of 2,2,2-trifluoroethylmethacrylate

The atom transfer radical polymerization of 2,2,2-trifluoroethylmethacrylate (TFEMA) was conducted by using ethyl-2-bromopropionate(EPN-B)/cuprous chloride(CuCl)/bipyridine(bpy) as the initiating/catalytic system and cyclohexanone as solvent, polymerization kinetics of TFEMA was studied, and the effects of initiator/catalytic system, amount of initiator and complexant , mole ratio of monomer on polymerization rate were investigated. The results showed that the poly(2,2,2-trifluoroethylmethacrylate) (PTFEMA) with narrow molecular weight distribution was obtained by using EPN-B/CuCl/bpy as initiating/catalytic system. In the experiment range, the reation was first order in kinetics and behaved like living polymerization. The polymerization rate improved with increasing EPN-B and bpy, and the appatent chain constant was 3.143×10~(-4),3.478×10~(-4),4.435×10~(-4) s~(-1) when the levels of EPN-B were 0.5,1.0,2.0 relative mole, respectively. The polymerization rate increased and polydispersion index (PDI) of PTFEMA decreased with increasing TFEMA]/EPN-B](mole ratio), but PDI kept at 1.15-1.23 no matter how the TFEMA]/EPN-B](mole ratio) changed.