Abstract: In this paper, spandex fabric 4,4′-methylene bis (MOCA) and polypropylene glycol (PPG) prepolymer or polytetrahydrofuran ether glycol (PTMG) prepolymer was casting molded forming polyurethane/spandex composites. The effect of spandex fabric on the tensile strength and damping properties of polyurethane matrix under small deformation was studied. It was shown that spandex fabric could strengthen the tensile strength and damping properties of polyurethane matrix under small deformation. After compounding, the modulus of elasticity of PPG and PTMG composites was increased 16.33 % and 11.39 %，and the tensile stress at 100 % deformation of PPG and PTMG composite was increased 55.81 % and 46.51 %. Moreover, the lag rate after 1 time stretchingretraction cycle of these two composites was 55.10 % and 62.83 %, compared with the matrix, the value was enhanced 26.12 % and 14.03 %, respectively.

Key words: spandex fabric, casting polyurethane, damping property, small deformation