Synthesis of functional polymers using anionic polymerization techniques

A new method for the quantitative functionalization of polymeric organolithiums with p-vinylbenzyl chloride at room temperature and in hydrocarbon solvent using anionic techniques has been developed. Also a method for the hydrogenation of telechelic secondary amine poly(diene)s has been developed.; The coupling reaction of polymeric organolithiums with p-vinylbenzyl chloride at room temperature and in hydrocarbon solvent is complicated by the recurrence of side reactions, leading to formation of products with twice the molecular weight of the base polymer. These side reactions can be circumvented by doing the reaction at low temperature in polar solvent or by changing the chain end of the living polymer to a less reactive species. A method in which the living chain and functionalizing agent were directly reacted is desirable to preserve the desired characteristic properties (high 1,4-repeat units) of diene polymerization in hydrocarbon media at ambient temperatures. In these investigations, experiments were performed to investigate the effects of various salts on the efficiency of coupling reactions. A continuous flow experiment was performed in order to determine the effect of instantaneous concentration variances. Analysis of reaction products was done utilizing NMR, UV/vis and MALDI-TOF MS methods in order to determine the nature of side products and dimeric species. Quantitative synthesis for the polymeric organolithiums was achieved by the addition of 10 equivalents of lithium 2,3-dimethyl-3-pentoxide to the reactions.; The hydrogenation of telechelic secondary amine functionalized polymers for use as chain extension agents is complicated by competing degradation reactions of polymers. For these reactions, telechelic secondary amine functionalized polydienes were synthesized using functionalized initiators and electrophilic terminating agents using methods developed in this laboratory. The polymer backbones were controlled in such a way that medium vinyl poly(butadiene)s or low vinyl poly(isoprene)s were synthesized. These polymers were chosen for the known elastomeric properties of the hydrogenated analogs. These reactions were optimized in order to achieve quantitative functionalization. Different homogeneous and heterogeneous catalysts were investigated for their ability to effect hydrogenation or hydrogenolysis in the presence of amines. A successful method was developed in which the telechelic amines were quenched with trimethylchlorosilane prior to hydrogenation. Reaction products were characterized using NMR, SEC and MALDI TOF MS analytical methods.