MDI聚氨酯/聚硅氧烷IPN的结构与力学性能

用MDI聚醚氨酯和含少量苯基的聚二甲基硅氧烷合成了一系列的聚氨酯／聚硅氧烷IPN阻尼弹性体，研究了材料的结构与力学性能．结果表明，当聚氨酯与聚硅氧烷的质量比为90：10时。IPN的抗张强度达41．57MPa，断裂伸长率为376％，并具有良好的阻尼性能，玻璃化转变温度范围大于80℃．聚氨酯／聚硅氧烷IPN具有细微的微相分离结构，聚硅氧烷在IPN中的微相尺寸为微米级，并趋向于分布在IPN的表面．

Structure and mechanical properties of MDI polyurethane/polysiloxane interpenetrating polymer networks

A series of Interpenetrating polymer networks (IPNs) of polyurethane (PU) and polysiloxane were successfully prepared at room temperature by mixing all the essential components and catalyst at the same time and these two networks were constructed simultaneously. The major components included PU prepolymer and polydimethylsiloxane blocked with 16% (mass fraction) poly-diphenylsiloxane segments. The former was prepared by reacting 4,4'-diphenyl methane diisocyanate (MDI) with poly(tetramethylene glycol) (PTMG) whose molecular mass is 2000 g-mol-1, and the latter was synthesized by crosslinking the terminal hyroxyl group of polysiloxane with tetramethyl orthosili-cate. The phase mixing of these IPN polymers was investigated by SEM and AFM, and the distribution of C, N, Si, 0 elements was also analyzed by XPS. All IPNs are high strength elastomers with only one glass-transition temperature. Polysiloxane is dispersed in PU continuous phase with domain size of several microns and inclined to distribute in the surface of IPNs. Polydiphenylsiloxane segments improve the compatibility of two polymers.