CO 2 copolymer diol (PPCD) with superior transparency is an indispensable raw material for the polyurethane, especially for waterborne polyurethane coatings. However, commercial PPCD is generally opaque. In this work, A sustainable, colorless and transparent PPCD was prepared by using carbon dioxide (CO 2 ) and propylene oxide (PO) as raw materials. Research shows that the increase in CO 2 content (from 23.5 wt.% to 31.5 wt.%) will affect the transparency and thermal stability of PPCD and the transparency of PPCD with 29.1 wt.% CO 2 content is even higher than 90%, while the 5 wt.% mass loss temperature reaches 240.1 ℃. Furthermore, a series of waterborne polyurethane (WPU) was successfully synthesized by prepolymer method with PPCD as the soft segment. With the increase of CO 2 content, the thermodynamic property of WPU was significantly improved. When CO 2 content increased from 23.50 wt.% to 31.50 wt.%, the tensile strength increased from 23.27 MPa to 34.63 MPa and the elongation at break decreased from 750.85% to 520.37%, accompanied by the glass-transition temperature increased from -49.7 ℃ to -34.5 ℃. In addition, it was found that WPU prepared by transparent PPCD has better tensile strength, transparency, and storage stability. A new inspiration was provided for its application in the fields of optical components, transparent medical materials and UV curable coatings.
A series of CO 2 copolymer-based waterborne polyurethanes with high solid content were successfully prepared by using CO 2 copolymer diol, isophorone diisocyanate, and dimethylol propionic acid as the donors of hydrophilic groups. In order to obtain of the emulsion with high solid content and good physical property, the synthesis conditions of CO 2 copolymer-based waterborne polyurethane were studied. The influence of dimethylol propionic acid content and synthesis process on the physical property of the emulsion was also investigated. Results show that CO 2 copolymer-based waterborne polyurethane with high solid content can be synthesized by chain expansion at relatively low temperature. The waterborne polyurethane emulsion particle size distribution was wide. As the content of hydrophilic groups in prepolymer increased, the viscosity and water absorption increased obviously, this is difficult to synthesize waterborne polyurethane with high solid content and low water absorption. Thermal gravimetric analysis shows that the higher the chain extending temperature of CO 2 copolymer-based waterborne polyurethane, the higher the thermal decomposition temperature. When the CO 2 molar content of CO 2 copolymer diol is about 30%, the CO 2 copolymer-based waterborne polyurethane has high strength and better water resistance.
危险品化学品经营许可证（带存储）