Poly(dimethyl siloxane)-containing five-block copolymers: Effects of resinblocks

A new generation of a series of five-block copolymers from acetophenone-for maldehyde resins (AFR), poly(dimethyl siloxane) (PDMS), and poly(vinyl pyrr olidinone) (PVP) or poly(styrene) (PS) were synthesised to modify the compa tibilities and surface properties of the block copolymers, For this purpose , PDMS-AFR-PDMS copolymers, which had different molecular weights and diffe rent AFR contents, were prepared first. These three-block copolymers were m ade diradicalic macroinitiators by a stepwise procedure. Vinyl pyrrolidinon e and styrene were polymerised by using these diradicalic macroinitiators t o prepare five-block copolymers. Intermediates and copolymers were characte rised by physicochemical methods, FTIR and 1 H-NMR spectra. The molecular w eights of block copolymers were measured by viscometry and by GPC. The solu bility and thermal properties of copolymers and contact angles of block cop olymeric films were measured, The overall results indicated that the chain- extended ketonic resins, even in the middle block, affect the characteristi cs of PDMS containing PVP or PS-block copolymers.