高温下甲基丙烯酸正丁酯ATRP的合环失活

The Cyclization Deactivation of n-Butyl Methacrylate by Atom Transfer Radical Polymerization in High Temperature

以2-溴代异丁酸乙酯[2-（EiB）-Br]为引发剂,CuBr/2,2＇-bpy为催化体系, 进行了甲基丙烯酸正丁酯（n-BMA）在异丙醇（IPA）/水中的原子转移自由基聚合,在16.5～100 ℃范围内研究了温度对聚合反应活性特征的影响.动力学结果表明,低温时反应有良好可控性,温度升至85 ℃以上时,聚合反应呈现出一系列非活性特征,聚合进行到一定程度后转化率不再增加,所有的链都成为死链.红外光谱的结果证明,较高温度时处于休眠态的增长链发生了合环反应,导致了增长链的永久失活.

The performance of atom transfer radical polymerization （ATRP） for n-butyl methacrylate, using Cu- Br/2,2＇ -bipyridine as catalyst and ethyl 2-bromoisobutyrate as initiator in 2-propanol/H20 within 16.5 - 100℃, was been investigated. The reaction is under control below 85℃. But it appeares some non-activated features over this temperature. All the dormant polymers became dead when the reaction turned to a certain extent. IR suggestes that the dormant chain cyclized to give a lactone end group.