棉籽油基聚氨酯弹性体的合成及性能.

Bio-based polyurethane with good comprehensive performance has attracted increasing attention. Cottonseed oilbased polyurethane (TO-PU) elastomers were synthesized from ozonized cottonseed oil-based polyols (OTO-polyols) with high hydroxyl value and castor oil (CO) by reacting with isophorone diisocyanate (IPDI). The structure of urethane bond was analyzed by Fourier transform infrared spectroscopy (FT-IR), and the formation of hydrogen bond was observed. The thermomechanical properties of synthetic TO-PU were examined by differential scanning calorimeter, thermogravimetric analyzer and universal testing. The thermo-mechanical properties are strongly dependent on the crosslinking density of TO-PU. The glass transition temperatures of polyurethane elastomers are −35 — −28 ℃, and the crystalline properties can be enhanced with the increase of castor oil. Correspondingly, the mechanical properties of TO-PU according to the tensile behavior of elastomers can be adjusted by turning the mass ratio of OTO-polyols to CO. The tensile strength of TO-PU-3 (m(OTOpolyols): m(CO)=7:3) exceeded 2.50 MPa, while the elongation at break can maintain above 150%. In comparison, the elongation at break of TO-PU-1 (m(OTO-polyols):m(CO)=9:1) can approach 400% by reducing the content of castor oil. The cottonseed oil-based polyurethane elastomer shows excellent thermal stability with the initial decomposition temperature above 240 ℃, and its three thermal degradation stages are caused by urethane groups, ester groups, and long carbon chains of polyols, respectively. [ABSTRACT FROM AUTHOR]