IN-SITU STUDIES OF THE ELIMINATION KINETICS FOR ANIONIC SYNTHESIZED POLY(PHENYL VINYL SULFOXIDE) DIBLOCK COPOLYMERS - SOLUBLE PRECURSORS TO POLYACETYLENE DIBLOCK COPOLYMERS

摘要

Polyacetylene (PA) with the simple repeating unit structure of -(CH=CH)- has been a subject for extensive research since the early seventies.[1] This is due to the polymer has unusual chemical, electrical and optical properties. PA with conductivity in the range of 104 S/cm (doped) as well as large third-order nonlinear optical activities have been reported. One of the most common and convenient synthesis method employed has been the Shirakawa's polymerization method of acetylene in the presence of Zeigler-Natta catalysis. The PA film thus obtained has both good mechanical strength and high electrical conductivity upon doping. Further studies on the fundamental properties and processing of the Shirakawa's PA films are, however, difficult due to the final products have complicate morphology and are infusible and insoluble in all solvents. Methods have thus been derived to prepare polyacetylene that can be processed even with high molecular mass. One method that achieved great success has been the precursor method. Either the Durham or the sulfaxide route has been used to prepare precursor polymers and copolymers to PA that are soluble and yet have excellent control on the chemical composition and molecular weight of the polymers. The precursor polymers could then be converted to the final forms of polyacetylene after subjected to a thermal or chemical treatment.