Composition dependence of physical properties of biodegradable poly(ethylene succinate) urethane ionenes

Abstract

To obtain an excellent comprehensive performance of poly(ethylene succinate) (PES), we have synthesized a series of poly(ethylene succinate) (PES) urethane ionenes (PESUIs) with various content of urethane ionic group by the chain extension reaction of dihydroxyl-terminated poly(ethylene succinate) and diethanolamine hydrochloride with hexamethylene diisocyanate as a chain extender, and we systematically investigated the composition dependence of the physico-chemical properties of PESUI through a series of characteristic techniques. The results of thermal and crystallization behaviors suggest that the incorporation of urethane ionic group slightly affects the glass transition temperature, melting temperature, and thermal stability, and significantly accelerates the crystallization rate of PES without changing the crystallization mechanism. The fastest crystallization rate was reached with the incorporation of 4 mol% urethane ionic groups. Spherulitic morphology observation indicates that nucleation density significantly increased, while spherulitic growth rate gradually decreased with increase in urethane ionic group content. Both complex viscosity and storage modulus initially increased and then decreased with increase in urethane ionic group content, and their maximum values were observed for the sample with 4 mol% of urethane ionic group. Mechanical properties slightly varied with urethane ionic group content.