▎ 摘　　要

NOVELTY - Polyurethane composition comprises a polyisocyanate component comprising at least one first isocyanate-terminated prepolymer obtained from the reaction of at least one first polyol with 1,4-bis(isocyanatomethyl cyclohexane), or a mixture of 1,4-bis(isocyanatomethyl cyclohexane) and at least one of a second aliphatic diisocyanate, an aromatic diisocyanate, an arylalkyl diisocyanate, or their mixture and an isocyanate-reactive component having a first diol and second diol, both diols are of low molecular weight of not less than 400 g/mol, and at least one second polyol with hydroxyl groups arranged to react with the at least one first isocyanate-terminated prepolymer to produce a polyurethane elastomer, where at least 50 wt.% of diisocyanate used to produce the at least one first isocyanate-terminated prepolymer is aliphatic diisocyanate, and the composition has a molar ratio of isocyanate functional groups to hydroxyl groups is 1-1.50, preferably 1.02-1.10, and is curable to produce an elastomer. USE - The polyurethane composition used in polyurethane elastomer used for erosion protection against moving solid particles, liquid droplets and slurries (claimed), and used as coating or thin film that which is less liable to hydrolysis and/or degradation under solar irradiation. ADVANTAGE - The composition provides polyurethane elastomers having excellent mechanical properties, superior erosion resistance against both sand particles and water droplets, and high environmental durability. DETAILED DESCRIPTION - Polyurethane composition comprises a polyisocyanate component comprising at least one first isocyanate-terminated prepolymer obtained from the reaction of at least one first polyol with 1,4-bis(isocyanatomethyl cyclohexane), or a mixture of 1,4-bis(isocyanatomethyl cyclohexane) and at least one of a second aliphatic diisocyanate, an aromatic diisocyanate, an arylalkyl diisocyanate, or their mixtures and an isocyanate-reactive component comprising a first diol and a second diol, both diols are of low molecular weight of not less than 400 g/mol, and at least one second polyol with hydroxyl groups disposed to react with the at least one first isocyanate-terminated prepolymer to produce a polyurethane elastomer, where at least 50 wt.% of diisocyanate used to produce the at least one first isocyanate-terminated prepolymer is aliphatic diisocyanate, and the composition has a molar ratio of isocyanate functional groups to hydroxyl groups is 1-1.50, preferably 1.02-1.10, and is curable to produce an elastomer having a mechanical strength not greater than 20 MPa, an elongation at break not greater than 500%, and a tensile set not less than 30%. INDEPENDENT CLAIMS are included for the following: (1) a liquid compound comprising 98 wt.% organic solvent, based on the total weight of the liquid compound; and (2) a polyurethane elastomer formed by curing the above-mentioned composition.