# Derivatization of PVA into Polyols Suitable for Fabrication of Rigid Polyurethane Foams—Preliminary Studies and Perspectives

## TL;DR

This study explores converting poly(vinyl alcohol) into polyols for making rigid polyurethane foams with good thermal resistance and biodegradability.

## Contribution

The first successful derivatization of PVA into usable polyols for rigid polyurethane foams with enhanced thermal resistance and biodegradability.

## Key findings

- PVA-derived polyurethane foams showed thermal resistance up to 150 °C.
- The foams achieved 54.6% biodegradation in cube form and 100% in powder form after 28 days.
- Physical and mechanical properties of the foams were comparable to traditional rigid polyurethane foams.

## Abstract

Polyols derived from poly(vinyl alcohol) (PVA) have not been reported before. The hydroxyalkylation of PVA with oxiranes leads to powdered or gum-like products that are not miscible with isocyanates and therefore useless as sources of polyurethane foams. Glycidol and ethylene carbonates were used to dissolve and convert PVA into liquid polyol. The physical properties of the PVA-derived polyol, such as the density, viscosity, and surface tension, were determined. The polyol was then used to obtain rigid polyurethane foams (PUFs). Foaming conditions were optimized, and the apparent density, volume water uptake, dimensional stability, heat conductance coefficient, pore size, thermal resistance, compressive strength, and glass transition temperature of the obtained PUFs were determined. The properties of the obtained PUFs were similar to those of classic rigid PUFs, but the thermal resistance of the former is better. Specifically, PVA-derived PUFs are thermally resistant at temperatures of up to 150 °C. Furthermore, they are ecologically safe; in standard soil conditions, 54.6% or 100% biodegradation of the foams in cube and powder form, respectively, was observed, as measured by BOD after 28 days of storage.