Abstract
Abstract 1H- and 13C-NMR studies carried out on poly(phenylacetylene)s and poly(pentadeutero-phenylacetylene)s prepared with Ziegler and metathesis type catalysts, revealed two different mechanisms which control the microstructure of acetylenic polymers. For the Ziegler-type catalysts, thermal induced reactions (intramolecular cyclization, aromatization, chain scission and cis-trans isomerization) of the cis-double bonds (isomerization after double bond formation) are responsible for the polymer microstructure. (For a review see: Progr. Polym. Sci., 8, 133 (1982).) Both isomerization "after” double bond formation as well as isomerization “before” double bond formation are responsible for the microstructure of polymers obtained with metathesis type catalysts. In both cases, the polymer molecular weight is controlled by the intramolecular cyclization of the cis-polymer chain end. Under reaction conditions where isomerization occurs mainly "before double bond formation, “pure” trans polymers having very high molecular weight are obtained (Polym. Prepr., 24 (1), 239 (1983); Polym. Bull., 9, 548 (1983)). The microstructure of several other acetylenic polymers will be commented on in relation with the polymerization mechanism and with the microstructure of (CH)x.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
