Preparation And Application Of Bio-based Polyols From Papeseed Oil In Polyurethane Foam

This paper introduced the synthesis process of rapeseed oil-based biological polyols by epoxidation and hydroxylation using rapeseed oil as the raw material. At the same time, the process conditions were discussed circumstantiatly. Then, combination polyether polyols were prepared by mixing the rapeseed oil-based polyols,with polyether polyols, foam stabilizers, catalysts, water and,foaming agents together. At last, polyurethane foams were prepared by reacting combination polyether polyols with isocyanate. The reactive properties of bio-based polyols were characterised by detecting hydroxyl, viscosity, epoxy, acid and iodine values respectively. And the foam performances were characterised by thermal conductivity, dimension stability, compression strength, density and closed vacancy rates.Technological parameters which comprising the reaction temperature, the dosage of hydrogen peroxide, formic acid and phosphoric acid and reaction time had a sharp influence on epoxy value of rapeseed oil. The optimal processing condition was obtained as following:the amount of phosphoric acid is 2%, the dosage of hydrogen peroxide is 1.6 times of theoretical amount and the amount of formic acid is 0.5 times of theoretical value, reacting temperature 60℃and reaction time 8h.The hydroxylation agent is DIPA.It was also discussed that the process conditions of the hydroxylation comprising reaction temperature, reaction time,and the mole ratio had important influences on the properties of rapeseed oil-based biological polyols and the foam performances. The most suitable technological parameters were:reaction temperature 160℃, reaction time 6 h and the mole ratio 1.3:1 (DIPA/epoxy bond per 100g epoxy oil)The structures of rapeseed oil, epoxy oil and the polyols were characterized by FTIR. The molecular weights were measured by GPC.