Preparation of natural rubber-based polyol by oxidative degradation under supercritical carbon dioxide for flexible bio-based polyurethane foams

Abstract

Nowadays, polyurethane foams play a key role in widespread applications, and their market demand is still growing globally. This work aims to prepare hydroxyl telechelic liquid natural rubber, a bio-based polyol, as a sustainable raw material and to enhance elastic properties of soft segment bio-based polyurethane foams. A hydroxyl telechelic liquid natural rubber with a viscosity-average molecular weight of 4.2 × 10³g/mol was successfully produced by oxidative degradation of natural rubber with hydrogen peroxide in the presence of supercritical carbon dioxide, then modifying the chain-end functionality to obtain hydroxyl number of 59 mg KOH/g. The functionality of hydroxyl telechelic liquid natural rubber was confirmed by FT-IR and ¹H-NMR. Bio-based polyurethane foams were then prepared by mixing the synthesized hydroxyl telechelic liquid natural rubber with commercial diisocyanate. Morphological properties and thermal stability of polyurethane foams were investigated.

Keywords

Flexible polyurethane foams oxidative degradation epoxidized natural rubber hydroxyl-terminated liquid natural rubber sorbitol

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