Cationic Grafting from Carbon Black. 4. Grafting of Poly(Oxytetramethylene) to Carbon Black by Ring-Opening Polymerization of Tetrahydrofuran Initiated by CO + ClO4- Groups on Carbon Black

Abstract

It was found that the cationic ring-opening polymerization of tetrahydrofuran (THF) was initiated by carbon black containing CO⁺ClO₄-groups, which had been introduced by the reaction of COCl groups with AgClO₄, in the presence of promoters such as epichlorohydrin (ECH) and diketene. It was confirmed that formation of poly(oxytetramethylene), i.e., poly-THF, was propagated from CO⁺ClO₄-groups on carbon black surfaces and effectively grafted onto it. The grafting ratio with ECH as promoter increased to 66.8% as conversion increased. The activation energy of the polymerization initiated by CO⁺ClO₄- groups in the presence of ECH was determined to be 8.1 kcal/mol. Furthermore, poly-ECH, poly(styrene oxide), and poly(propylene oxide) can be grafted onto carbon black surfaces by the ring-opening polymerization of the corresponding alkylene oxides with CO⁺ClO₄- groups on the carbon black as initiator. The polyether-grafted carbon black obtained from the above polymerization produced a stable colloidal dispersion in a good solvent for polyether.