Anionic Copolymerization of α-Methylstyrene(AMS)and Styrene(St)under the Mild Temperature
简介：An effective strategy for enhancing the heat resistance of polystyrene(PS)with regard to its glass transition temperature(Tg)involves the anionic solution copolymerization of α-methylstyrene(AMS)with styrene(St),typically requires much lower temperature(-25℃)and multi-step monomer feeding to achieve higher number-average molecular weight(Mn)block copolymers.However,the anionic copolymerization of AMS and St under the mild temperature remains largely unexplored.This study systematically investigated the anionic copolymerization of AMS and St using n-BuLi in nonpolar solvent(-25℃ to 25℃)through both one-step and two-step approaches.We demonstrated that one-step copolymerization at 25℃ yielded only 1-3 terminal AMS units,with higher feed ratios(5 wt％-20 wt％)increasing AMS incorporation but reduc-ing the exact molecular weight(MW)due to enhanced depolymerization,as evidenced by MALDI-TOF MS.Temperature-controlled AMS conver-sion at-15℃ achieved 98％AMS conversion(5 wt％feed)by suppressing side reactions and lowering the[M]e,while 50℃(near Tc)almost pre-vented incorporation.Despite t-BuOK regulation induced broader PDI(1.24)via reactive[(polymer-Li)OR]K intermediates,while other systems showed narrow distributions,t-BuOK outperformed THF in enhancing AMS incorporation via efficient ion pair dissociation.In comparison,the two-step polymerization approach demonstrated superior performance,achieving both higher AMS conversion efficiency and preferential incor-poration at the initiation end.At a 20 wt％AMS feed ratio,this method yielded copolymer chains containing up to 6 AMS units on average.Ther-mal analysis revealed a composition-dependent single Tg,which exhibited a systematic increase with higher AMS incorporation content.These results collectively demonstrate the precise control over AMS incorporation and heat resistance achievable through the manipulation of poly-merization conditions.展开
学者：Yun-HanWangRui-XueZhangHai-taoLengJia-XingXUXu-WenLIYan-ShaiHong-weiMaYangHAN
关键词：Anionic copolymerizationα-MethylstyreneStyrene
在线出版日期：2026-04-03 （网站首发日期）
