Renewable resource lactide derived novel materials: Synthesis and characterization of fluorinated polylactides, epoxy terpolymers, oligoethylene-end-capped-polylactides and poly(ester amide)s

This dissertation includes the synthesis of four types of copolymers derived from lactide monomer. The chemical building block of polylactide, the lactide monomer, is derived from lactic acid, which is a fermentation product of corn sugar.; Growing environmental awareness throughout the world has triggered the search for new materials and processes. The need for renewable resource materials in chemical building blocks has become more prominent for commodity thermoplastics where depletion and rising costs of petroleum resources is a consideration. This study is focused on fulfilling this need and finding methods to incorporate lactide into polymeric materials for commercial use.; The first part of this dissertation focuses on the synthesis of fluorinated polylactides. This goal was accomplished through two different routes. During the first route the synthesis of fluorinated lactide monomer was carried out using an electrophylic fluorinating agent N-flurobenzenesulfonimide (NFBS) under mild conditions to obtain the fluorinated monomer, alpha,alpha '-difluorolactide. Its ring opening polymerization was carried out in tetrahydrofuran with an n-BuLi initiator. In the second route, partial fluorination of the commercially available polylactide was accomplished through the formation of carboanion using a NaH base followed by the addition of the fluorinating reagent NFBS.; During the second part of the study, the incorporation of lactide into epoxy resins was investigated. The terpolymerization of lactide, hexafluoroisopropylidenediphenol (6F-Bis-A) and diglycidyl ether of bisphenol-A (DGEBA) was accomplished using tertiary phosphonium, ammonium catalysts and crown ether complexes.; In the third part of this study, the synthesis and the potential use of oligoethylene end capped polylactides as compatibilizers in polylactide-polyethylene blends, and nucleants were investigated. In this study commercially available linear primary alcohol oligoethylene derivatives (Unilin alcohols) were used as the macroinitiator in the ring opening polymerization of lactide to obtain the corresponding copolymers.; In the final part of this research, poly(ester amide)s based on lactide and depsipeptides were investigated. Two different depsipeptides, commercially available morpholine-2,5-dione monomer and 6,6'-dimethyl-2,5-morpholinedione synthesized in our laboratory, were used for copolymerization with L-lactide. (Abstract shortened by UMI.)...