不同硬段含量的PU及其纳米复合材料

Studies on Polyurethane with Different Hard Segment Ratio and Its Nanocomposites

制备了不同硬段含量的聚氨酯(PU)及其PU/有机蒙脱土(OMMT)纳米复合材料。研究结果表明,随着PU分子链中硬段含量的增加,PU分子链的刚性提高,进入硅酸盐片层间的位阻增大,使插层变得困难,从而导致进入该硅酸盐片层间的PU分子链减少。OMMT对PU有增强增韧作用,但随着PU分子链中的硬段含量增加,OMMT的增强效果下降。PU及其PU/OMMT纳米复合材料的热稳定性均随着PU分子链中的硬段含量增加而下降。

Polyurethane with different hard segment ratio and polyurethane/organically modified montmorillonite （OMMT） nanocomposites was prepared. As hard segment ratio in the polyurethane chains increases, the polyurethane chains which diffused into the layer galleries are difficult. Therefore, the amount of polyurethane chains intercalated into the OMMT layer galleries decreases. The OMMT has strengthening and toughening effect for polyurethane; however its strengthening effect decreases with increasing the hard segment ratio. Compared with those of PU523, the tensile and tear strength of PU523/OMMT（95/5） nanocomposites increases by about 52% and 26%; however, the tensile and tear strength of PU413/OMMT（95/5） nanocomposites increases by about 18% and 16%than those of PU413. The thermal stability of the polyurethane and polyurethane/OMMT nanocomposites decreases with raising the hard segment ratio.