Straightforward Synthesis of Amido Polyols from Epoxidized Soybean Oil for Polyurethane Films

Abstract

This work reports a straightforward and selective method for the preparation of a polyol that can be used in the manufacture of polyurethane (PU) films. The polyol, from the N‐hydroxyalkylamides family, is obtained from the selective amidation and oxirane ring opening of epoxidized soybean oil (ESO) with the amino alcohol N‐methylethanolamine (N‐MEA). The reaction is carried out under mild conditions and in the absence of solvents and catalysts. Other similar amino alcohols (namely monoethanolamine (ETA), 5‐amino‐1‐pentanol (PEA), and 2‐(2‐aminoethoxy)ethanol (AEE)) are also used to carried out the amidation of ESO. However, for these amines, the amidation and/or oxirane ring opening of ESO is not complete. Therefore, the N‐hydroxyalkylamide obtained from the amidation of ESO with N‐MEA is chosen as the polyol for the preparation of PU films. The PU films are obtained from the reaction with a trimer of hexamethylene diisocyanate (Tolonate) and hexamethylene diisocyanate (HDI). Curing proceeds at room temperature, without catalyst. It is shown that the properties of the resulting PU films are dependent on the amount of Tolonate in the formulation.

Versatile Epoxidized Soybean Oil-Based Resin with Excellent Adhesion and Film-Forming Property

“…To evaluate the performance of the MHE films, their tensile strength and elongation at break were compared with those of some biomass-based films in literature. ,− According to our survey on literature shown in Figure g, so far, the oil-based films with the highest tensile strength were developed very recently by Zhang’s team . In the study of Zhang’s team, the epoxidized linseed oil was first reacted with CO 2 to produce cyclic carbonate which was then crosslinked by different diamines, resulting in non-isocyanate polyurethanes (NIPUs) films with tensile strength of 19–69 MPa and elongation at break of 15–179% .…”