Synthesis of polyols and polyurethanes from vegetable oils–kinetic and characterization

The demand of vegetable oils by several sectors of the chemical industry is growing at a fast pace fueled by the fossil oil scarcity, its unpredictable price fluctuations and the ever increasing environmental concerns. The present work reports for the first time the synthesis of polyols and polyurethanes (PUs) from linseed seed (Linum usitatissimun L.) and passion fruit (Passiflora edulis Sims f. flavicarpa Degener) oils. The in situ epoxidation and hydroxylation of vegetable oils in a single step was successfully accomplished using a mixture of hydrogen peroxide (H₂O₂) and formic acid. Kinetic studies were performed on this system. The oils and the corresponding polyols were characterized by Fourier transform infrared (FT-IR), gel permeation chromatography (GPC) and thermogravimetry (TG)/derivative termogravimetry (DTG). The PUs were characterized by FT-IR, TG/DTG, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The study revealed a marked deviation on the properties between the starting materials and the end products. The PUs produced showed similar dynamic mechanical properties.