Application of cesium hydroxide monohydrate for ring opening polymerization of monosubstituted oxiranes : characterization of synthesized polyether-diols

Abstract

Cesium hydroxide monohydrate (CsOH·H2O) activated by cation complexing agents, i.e., 18C6 or C222 was applied as initiator of monosubstituted oxiranes polymerization. Propylene oxide (PO), 1,2-butylene oxide (BO), styrene oxide (SO) and some glycidyl ethers were used as monomers. All processes were carried out in tetrahydrofuran solution at room temperature. Such polymers, as PPO-diols, PBO-diols and PSO-diols, are unimodal and have molar masses Mn = 2000-5100. Their dispersities are rather high (Mw/Mn = 1.17-1.33). Moreover, PPO-diols and PSO-diols are not contaminated by monools with unsaturated starting groups. Poly(glycidyl ether)s are, in general, polymodal. For example, poly(isopropyl glycidyl ether)-diols are bi- or trimodal, whereas poly(allyl glycidyl ether)-diols possess two or even six fractions. Molar masses of main fraction are 4200-6400, and the second fraction is much lower, namely 600-2600. Dispersities of some fractions are very low (Mw/Mn = 1.01-1.07). Polymodality of polymers obtained was discussed in terms of the formation of two or more species propagating with different rate constants.