Properties of polyurethanes derived from poly(diethylene glycol terephthalate)

The synthesis of linear and crosslinked polyurethanes based on α,ω-dihydroxypolydiethylene glycol terephthalate (PDET) is described. Prior to the preparation these materials, a PDET polymer was obtained by conventional condensation reaction between dimethyl diethylene glycol, well-characterized fraction with number average molecular weight 3,650 g mol−1 chosen for polyurethanes. Specifically, three were prepared: pure polyurethane 4,4′-diphenylmethane diisocyanate (MDI), chain extended MDI, 1,4-butanediol as extender, synthesized from polyfunctional isocyanate. Thermal, mechanical, dielectric gas transport properties studied, showing excellent performance. In particular, rubber-like flexible materials elongation values over 1000%, due low glass transition temperature PDET. Furthermore, it observed that in particular polyurethane, behave barriers.