Kinetics and Molar Mass Evolution during Atom Transfer Radical Polymerization of n-Butyl Acrylate Using Automatic Continuous Online Monitoring

摘要

Homogeneous bulk atom transfer radical polymerization (ATRP) of n-butyl acrylate (BA) was monitored by automatic continuous online monitoring of polymerization reactions (ACOMP).This allowed simultaneous monitoring of conversion,weight-average molar mass M_w,and intrinsic viscosity,from which the viscometric average molar mass M_v,and an index of polydispersity M_W/M_v,were also determined.For ATRP of BA,initiated by methyl 2-bromopropionate and catalyzed by copper bromide complexes with 4,4'-di(5-nonyl)-2,2'-bipyridine,ACOMP yielded an equilibrium constant,K_(eq)(90 deg C)=5.8 x 10~(-10).The polymerizations exhibited first-order kinetics with respect to monomer and initiator concentrations,as expected for ATRP.These results set the stage for further detailed understanding of kinetics and mechanisms in ATRP reactions using ACOMP,where temperature and concentration dependences can be readily monitored.