Synthesis of Primary-Alcohol-Terminated Polyepichlorohydrin with Molecular Weight of 4000 to 12000

Abstract : Previous studies of cationic polymerization of epichlorohydrin (ECH) indicate that the commonly used initiator systems, Lewis acid alcohol or tertiary oxonium salt alcohol complexes give polyepichlorohydrin (PECH) whose average molecular weight is less than 4000 and the terminal groups are sterically hindered secondary alcohols. In our study, a novel pseudo-living polymerization system of epichlorohydrin has been developed, using 1,4- butaneditriflate (BDT) as the initiator. The advantages of BDT as the initiator are: (1) There are no head groups on the polymeric chains because BDT is difunctional, and (2) the tail groups (triflate esters) of the polymeric chains can be converted to a variety of functional groups. Our experimental results demonstrate that telechelic PECH having molecular weights in the range of 4000 - 15000 and with different functional groups can be synthesized. For example, the end-groups of PECH can be phenoxide groups or 1-hydroxybutyl groups; these have been characterized by UV, FTIR and NMR studies. Furthermore, PECH with different alcohol structures and the functionalities of two and four have been synthesized. Telechelic polymerization, Epichlorohydrin, Initiator, Molecular weight, 1,4-Butaneditriflate, Kinetic studies, End groups.