Synthesis of Comblike Poly(styrene-b-isoprene) Block Copolymers and Their Properties in Good and Selective Solvents

Abstract

Comblike block copolymers having a poly(chloroethyl vinyl ether) backbone and poly(styrene-b-isoprene) side chains, i.e., PCEVE-g-(PS-b-PI), of different molar masses and chemical compositions were synthesized by “grafting onto” technique using the coupling reaction of acetal−PSLi (F−PSLi) chains onto the reactive functions of a PCEVE backbone, followed, in a second step, by the grafting of living PIDLi chains onto the acetal ends of PS branches activated by trimethyl silyl iodide. The comblike copolymers exhibit low polydispersity, high molar masses, and a controlled number of branches. Their characteristics and behavior were further studied in the solid as thin films and in good and selective solvents. Atomic force microscopy (AFM) shows isolated uniform molecules that adopt an ovoid conformation. The solution behavior of these comblike polymers was investigated by dynamic light scattering (DLS), both in a good solvent of the PS and the PI blocks and in selective solvents of the outer PI blocks. Dependi...