Cationic Grafting from Carbon Black. IX. Cationic Ring-Opening Polymerization and Copolymerization of 3,3-Bis-(Chloromethyl)Oxetane Initiated by Acylium Perchlorate Groups on Carbon Black

Abstract

The cationic ring-opening polymerization of 3,3-bis(chloromethyl)-oxetane (BCMO) was found to initiate by acylium perchlorate groups on carbon black, introduced by the reaction of acyl chloride groups with silver perchlorate. It was confirmed that poly-BCMO propagated from carbon black and effectively grafted from the surface. The percentage of grafting of poly-BCMO increased with increasing conversion and reached about 50%. The grafting efficiency, however, decreased with the extent of polymerization. This suggests that ungrafted polymer formed by chain transfer at higher conversion. The activation energy of the polymerization was estimated to be 28.5 kJ/mol. Furthermore, acylium perchlorate groups on carbon black are able to initiate the copolymerization of BCMO with tetrahydrofuran (THF). Poly-(BCMO-co-THF)s of various compositions were grafted from the surface; depending on the propagation of the copolymer, the percentage of grafting was as high as about 40%. The poly-BCMO-grafted and poly(BCMO-co-THF)-grafted carbon black gave stable colloidal dispersions in organic solvents.