Synthesis of poly(2‐ethyl‐2‐hydroxymethyltrimethylene carbonate)

Abstract

Abstract2‐Ethyl‐2‐hydroxymethyltrimethylene carbonate (5‐ethyl‐5‐hydroxymethyl‐1,3‐dioxan‐2‐one) (1) was treated with trimethylsilyl chloride, benzyl chloroformate and phenyl isocyanate to give the corresponding 5,5‐disubstituted 1,3‐dioxan‐2‐ones 2, 3 and 4. These monomers were subjected to anionic ring‐opening polymerization reactions with lithium alcoholates as initiators. The polymers obtained usually exhibit linear structure; under special conditions slightly branched polymers were obtained. Poly(2) and poly(3) were subjected to polymer‐analogous reactions—hydrolysis and hydrogenation—by which the protective groups are removed and poly(1) was obtained. The hydroxyl groups in poly(1) are susceptible to a polymer‐analogous reaction. Poly(4) obtained by reaction of poly(1) with phenyl isocyanate was identical with poly(4) obtained by ring‐opening polymerization of the corresponding monomer 4. All these new monomers were characterized by means of 1H and 13C NMR spectroscopy as well as elemental analysis. The polymers were analyzed with respect to their primary structure, their molecular weight and molecular weight distribution. The thermal properties of some of the polymers are discussed.