Modification of tung oil–based polyurethane foam by anhydrides and inorganic content through esterification process

Abstract

In this study, we have reported the synthesis of modified polyol from tung oil. The synthesis involves three steps: first, conversion of tung oil to hydroxylated tung oil by hydroxylation; second, alcoholysis with triethanolamine; and finally, the esterification of polyester polyol when reacted with phthalic anhydride (PA) or maleic anhydride (MA). Boric acid is also introduced into the polyol by chemical modification, which enhances the thermal properties of polyurethane foam (PUF). PUF is formulated by the reaction between polyol and isocyanate. A systematic comparison of flame retardancy and mechanical and thermal properties of modified PUF has been examined. The structural properties of modified polyol were characterized by Fourier transform infrared spectroscopy, proton NMR spectroscopy, and gel permeation chromatography, while the thermal and mechanical properties of the formulated PUF were studied by scanning electron microscopy, limiting oxygen index, differential scanning calorimetry, Izod impact, and flexural and compression strength. Thus PUF prepared from modified polyol with a proper distribution of soft and hard segments possesses better mechanical and thermal properties. The PA-modified foams show better properties compared to unmodified and MA-modified foams due to the aromaticity and crosslinking behavior of PA.

Hidroxilação dos óleos de girassol, milho e crambe e caracterização química dos polióis vegetais obtidos

“…Os polióis são matérias-primas utilizadas na produção de poliuretanas (PUs), que são polímeros versáteis com uma gama de aplicações [9]. Esses polímeros são utilizados na indústria automotiva, calçadista, construção civil, fabricantes de móveis, embalagens, revestimentos, tintas, adesivos e espumas [10,11,12,13].…”

Effects of Tung Oil-Based Polyols on the Thermal Stability, Flame Retardancy, and Mechanical Properties of Rigid Polyurethane Foam

“…Vegetable oils have double bonds, ester groups and other reactive sites that can be modified to form new polyol structures [2]. Vegetable oils such as castor oil, palm kernel oil [3,4], rapeseed oil [5], and tung oil [6] have been used to produce RPUF. RPUF has been widely used in materials for building insulation due to its excellent mechanical performance.…”

Synthesis and properties of polyurethane elastomers based on renewable castor oil polyols

“…VOs are universal available, biodegradable, and of low price . Many renewable and biodegradable polyurethanes prepared with natural VOs, like castor oil, rapeseed oil, soybean oil, jatropha oil, canola oil, Mesua ferrea L. seed oil, tung oil, and corn oil, have been reported. Generally, most natural VOs do not have hydroxyl groups to react with isocyanate group directly .…”