Structurally-Controlled Synthesis of Amphiphilic Polymers Having Tetrahydropyrans in their Main Chains by Ring-Opening Polymerization Meghod and Appearance of their Functions

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1. Synthesis and Ring-Opening Polymerization of Novel Bicyclic OxalactamsTwo new bicyclic oxalactams, 2-oxa-5-azabicyclo[2.2.2]octan-6-one (2,5-BOL) and 2-oxa-6-azacicyclo[2.2.2]octan-5-one (2,6-BOL) were synthesized and their ring-opening polymerizabilities were examined. 2,5-BOL was polymerized in the presence of potassium pyrrolidonate and N-benzoyl BOL as catalyst and activator respectively to give a polyamide having cis-2,5-linked tetrahydropyran rings in the main chain.The corresponding polyamide consisting of trans-2,5-linked tetrahydropyran rings was prepared by direct polycondensation of trans-5-amino-tetrahydropyran-2-carboxylic acid using triphenyl phosphine and hexachloroethane as activators. The trans-polyamide was much less soluble in comon organic solvents compared with the cis polyamide, and it dissolves in trifluoroethanol, hexafluoro-2-propanol, and m-cresol. 2,6-BOL did not undergo-anionic polymeri- zation, and afforded only a dimeric adduct in a low yield. In contra … More st, 2,6-BOL was polymerized relatively easily with cationic initiators such as trifluoro- methanesulfonic acid to give oligoethers containing 6-membered lactam rings in the main chains.2. Synthesis of Polyesters Having Tetrahydropyran Rings in their Main ChainsChains A polyester composed of trans-2,5-linked tetrahydropyran rings was prepared by direct polycondensation using triphenyl phosphine and hexachloroethane as activators. The polyester became highly crystalline after annealing at elevated temperature, and showed limited solubility in organic solvents. Three 2,6- dioxabicyclo[2.2.2]octan-3-one derivatives having at 4-position an ester group of which alcohol moiety was oligooxyethylene chains or a benzyl group were newly prepared. These monomers readily underwent cationic polymerization to produce polyesters having 2,5-linked tetrahydropyran rings in the backbones and the corresponding ester groups as the side chains. The polyesters showed much improved solubilities compared with the parent polyester without ester side chains. These polyesters were very slowly hydrolyzed at 30ﾟC when their films were immersed in a boffer solution adjusted at pH7.2. Less