| abstract |
The invention relates to a polyurethane film material and a preparation method thereof. The preparation method comprises: firstly preparing 35-50 parts of aliphatic diisocyanate, 5-10 parts of aliphatic monofunctional isocyanate and a polyether polyol with a molecular weight of 500-3000 40-70 parts of alcohol, 0-10 parts of small molecular polyol and 0-0.3 parts of second catalyst are used as raw materials to prepare NCO-terminated polyurethane prepolymer, and then 50-72 parts of NCO-terminated polyurethane prepolymer; hydroxyl-terminated mixture 28-46 parts; 0.5-1.5 parts of antioxidant, 1-1.5 parts of light stabilizer, 0.1-0.5 part of thixotropic agent and 0-0.5 part of first catalyst are mixed to obtain a mixture, and polyurethane is prepared by casting reaction into film. film material. The polyurethane film material includes high molecular weight polyurethane with a molecular weight of more than 400,000 and low molecular weight polyurethane with a molecular weight of 100,000 to 200,000. The polyurethane film material prepared by the invention has dual molecular weight distribution, no crystal point, and has the advantages of good thermal stability, excellent optical performance and the like. |