Effects of Bio-Polyols Based on Rapeseed Oil on the Selected Properties of Flexible Polyurethane Foams

摘要

Nowadays, in the production of polyurethane foams (PUFs), petrochemical raw materials are still used commonly. However, the observed trends and legal requirements of the European Directive and the limited resources of petroleum make the PUFs producers increasingly interested in using raw materials from renewable sources. The bio-polyols from vegetable oils are such natural hydroxyl derivatives that can replace petrochemical polyols in the synthesis of PUFs. In our investigation a formulation for preparing flexible polyurethane foams have been modified by replacing up to 50 wt.% of petrochemical polyols with bio-polyols derived from rapeseed oil. The used bio-polyols were obtained in the epoxidation process of unsaturated bonds and oxirane ring opening by means of diethylene glycol, 1,2-propanediol (1,2 PDO) and 1,3-propanediol (1,3 PDO) as well as isopropanol. The influence of polyurethane formulation on foaming process was evaluated using Format device. The PUFs that have been obtained using selected bio-polyols were characterized by determining their cell structure and physical-mechanical properties such as apparent density, resilience, stress-strain characteristic including, hysteresis, and hardness of the foams. The replacement of the petrochemical polyol with the bio-polyols has caused changes in foaming process as well as influenced on apparent density of prepared foams, which were in the range of 27-32 kg/m3. The addition of bio-polyols in particular obtained by using diethylene glycol, 1,2 PDO and 1,3 PDO as oxirane ring opening agents caused an improvement in physical and mechanical properties of modified foams.