Synthesis and characterization of homo‐ and co‐oligomers of tetracyclo[4.4.0.12,5.17,10]dodecene‐3 by cationic polymerization

Cationic homopolymerization of tetracyclo[4.4.0.12,5.17,10]dodecene-3 (TCD) and its copolymerization with styrene (St) were carried out with the catalyst system Al(C2H5)Cl2/tert-butyl chloride, and the effects of temperature and TCD/St feed ratio, on polymer solubility, molecular weight and glass transition temperature (Tg) were investigated. A soluble oligomer with a molecular weight of 1000 was prepared by homopolymerization of TCD at +10°C or by copolymerization with St (>4 mol-% in the feed) at −50°C. 13C NMR analysis of the TCD homo- and TCD/St copolymers revealed both 3,4- and 3,11-additions for the repeating units from TCD. A polymerization mechanism including initiation, propagation, termination (deprotonation), and further crosslinking reactions is proposed. Moreover, it was demonstrated that a TCD/St copolymer with a controlled Tg in the range of 100 to 260°C can be prepared by selecting the TCD/St composition.