Syntheses of epoxyurethane polymers from isocyanate free oligo-polyhydroxyurethane

Abstract

Polyepoxyurethane polymers were synthesized from PolyHydroxyUrethane (PHU) prepolymers terminated amine and epoxy multifunctional. In order to ensure this, PHU prepolymers was synthesized from the reaction between α, ω-bis-cyclic-carbonates (poly(propylene)oxide bis-carbonates) and different excess of diamines (ethylenediamine) to terminate these prepolymers by amine with differents chain length. Then, these aminotelechelic PHU oligomers were re-used in formulation with multifunctional epoxy compound (Bisphenol A Diglycidyl Ether, Di-epoxydized Cardanol or Phloroglucinol Tris Epoxy) to synthesize polyepoxyurethane polymers called also hybrid polymers. Firstly, the raw materials were analyzed in order to determine proportion stoichiometry for carbonate/amine and of hybrid materials formulations. Secondly, for the purpose to demonstrate that the reaction carbonate/amine form hydroxyurethane compound, a model study was realized. Then, syntheses and analyzes of prepolymers terminated amine by 1H, 13C NMR, TGA and DSC was conducted. Once these oligomers analyzed, the hybrid polymers were formulated from epoxy compounds at different temperatures to determine the best cross-linking proceed. Epoxyurethane polymers were characterized by ATG, DSC and measurement of their swelling index and gel content. These materials exhibited glass transition temperature between −5°C and 42°C and a thermal stability above 320°C at 30% of weight loss.