ORGANOTITANIUM(IV)-CATALYZED CYCLOPOLYMERIZATIONS OF 1,2-DIISOCYANATES AND CYCLOCOPOLYMERIZATIONS OF MONOISOCYANATES WITH 1,2-DIISOCYANATES

1,2-Diisocyanates were cyclopolymerized using CpTiCl(2)N(CH3)(2). Trea tment of 1,2-diisocyanatodecane with CpTiCl(2)N(CH3)(2) in THF effecte d its cyclopolymerization with stoichiometric control over molecular w eight and with M(w)/M(n) ranging from 1.2 to 1.8. IR, H-1 NMR, and C-1 3 NMR spectra of the resulting polymers indicate that the monomer unde rwent complete cyclization. Studies of the solution properties of poly (1,2-diisocyanatodecane) showed that it maintains a smaller hydrodynam ic volume than poly(n-hexyl isocyanate) at equivalent molecular weight s. Living poly(n-hexyl isocyanate) mas end-capped with blocks of poly( 1,2-diisocyanatopropane) and poly(1,2-diisocyanatodecane). TGA and DSC studies of these block copolymers showed that the individual block se gments decomposed at the same temperatures as their respective homopol ymers. Random copolymerizations of n-hexyl isocyanate with 1,2-diisocy anatopropane and 1,2-diisocyanatodecane were conducted. TGA studies of these macromolecules showed that the decomposition temperature of the copolymer was a function of its 1,2-diisocyanate content, and the inc orporation of a relatively high mole percent of the diisocyanate monom er was necessary to observe an increase in the decomposition onset of the copolymer.