Brush Type Copolymers of Poly(3-hydroxybutyrate)and Poly(3-hydroxyoctanoate) with Same Vinyl Monomers via 'Grafting From' Technique by Using Atom Transfer Radical Polymerization Method

摘要

Brush type graft copolymers of poly(3-hydroxybutyrate) (PHB) andpoly(3-hydroxyoctanoate) (PHO) with methylmethacrylate, (MMA), styrene, (S), andn-butylmethacrylate, (n-BuMA) were obtained by using Atom Transfer RadicalPolymerization Method, (ATRP), via "grafting from" technique. Firstly PHB andPHO were chlorinated by passing chlorine gas through their solution in CHCI_3/CCI_4(75/25 v/v) mixture and CCI4, respectively, in order to prepare chlorinated PHB,PHB-CI, and chlorinated PHO, PHO-CI, with different chlorine contents. The deter-mination of the chlorine content in chlorinated poly(3-hydroxyalkanoate) (PHA-CI)was performed by the Volhard Method. Then ATRP of vinyl monomers was initiated byusing PHA-CI as macroinitiators in the presence of cuprous chloride (CuCI)/2,2'-bipyridine complex as catalyst, at 90 °C in order to obtain brushes containing PHA5.The polymer brushes were fractionated by fractional precipitation methods and the yvalues calculated from the ratio of the volume of nonsolvent (methanol) and thevolume of solvent (chloroform) of brushes varied between 0.82 and 6.5o dependingon the composition of brushes. The polymer products were characterized by gelpermeation chromatography (GPC), ~1HNMR, FTIR, thermogravimetric analysis (TGA)and differential scanning calorimetry (DSC) techniques.