Block Copolymerization. II. Polymerization of Tetrahydrofuran by Bifunctional Cationic Initiator

Abstract

Polymerization of tetrahydrofuran (THF) by 2-methyl-1,3-dioxolenium perchlorate clarified the living nature of the polymerization. Although the initiation reaction is slower than the propagation reaction, the bonding mechanism of the initiation was shown from NMR and IR, and the formation of one polymer chain from one catalyst molecule was substantiated. Poly-THF di-cation of Mn 173000 to 322000 was prepared in high vacuum system by using a bifunctional initiator, 2,2′-octamethylene bis-1,3-dioxolenium perchlorate. Chain scission by sodium and n-butyl alcohol proved the presence of the living di-cation. The deviation from monodisperse molecular weight distribution is explained by the rate of the initiation reaction.