Effect of hydroxylated soybean oil and bio-based propanediol on the structure and thermal properties of synthesized bio-polyurethanes

• State of knowledge about bio-based polyols used in polyurethane synthesis.
• Properties of polyurethanes which contain bio-based polyols.
• Dynamical mechanical and spectroscopy analysis of bio-polyurethane materials.

The aim of this work was to obtain bio-polyurethanes using synthetic compounds and bio-components, i.e. bio-glycols. Bio-polyurethanes were prepared by means of the prepolymer method. Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% by weight of commercial polyether and 25% by weight of hydroxylated soybean oils (H2 or H3), the latter being obtained in the reaction with bio-glycol during the hydroxylation process. Bio-components were also used as chain extenders of prepolymer, i.e. bio-based 1,2- or bio-based 1,3-propanediol (1,2bioPDO or 1,3bioPDO). The reaction was catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO). The influence of the content of low molecular chain extenders on the structure and thermomechanical properties of the obtained bio-polyurethanes was investigated. The FTIR analysis demonstrated that different types of bio-propanediol change the chemical structure of the obtained bio-polyether urethanes. The results of thermomechanical analysis showed that the application of 1,2-bio-propanediol as a chain extender was advantageous in comparison to bio-based 1,3-propanediol; the polyurethanes produced with 1,2-bio-propanediol exhibited higher storage modulus and lower loss modulus.