气相、沉淀、稻壳SiO2/聚氨酯复合材料的力学性能和吸水性比较

比较了气相、沉淀和稻壳SiO2的物理性质,并利用上述3种SiO2与聚氨酯(PU)复合,考察了SiO2含量(1wt%,3wt%,5wt%)和种类对SiO2/PU复合材料的拉伸性能和吸水性的影响。结果表明:3种SiO2均能够提高SiO2/PU复合材料的力学性质,复合材料的拉伸强度、模量和断裂伸长率均随SiO2含量增加而增加。当SiO2含量相同时,拉伸强度和断裂伸长率的变化顺序为:气相SiO2/PU>沉淀SiO2/PU>稻壳SiO2/PU,拉伸模量的变化顺序为:气相SiO2/PU>稻壳SiO2/PU>沉淀SiO2/PU.对于同一种SiO2/PU复合材料,吸水性随SiO2含量和温度增加而增加,含量相同时,3种SiO2/PU复合材料的吸水性由低到高的顺序是:稻壳SiO2/PU<沉淀SiO2/PU<气相SiO2/PU。

Comparison of mechanical properties and water absorption behavior of gas phase,precipitation and rice husk silica filled polyurethane composites

First the physical properties of gas phase,precipitation and rice husk silica were compared,then mechanical properties and water absorption behavior of polyurethane(PU) composites filled with these silica were studied with respect to filler loading(1 wt %,3 wt % and 5 wt %) and filler type.It was shown that the mechanics properties of composites were improved more or less depending on the silica type and content.For the same type SiO2,tensile strength,elongation at break and tensile modulus of composites increased with increasing of silica loading.For the same content of SiO2,the tensile strength and elongation at break of composites from high to low order was : gas phase SiO2 /PU > precipitation SiO2 / PU > rice husk SiO2 / PU,the tensile modulus from to low high order was: gas phase SiO2 /PU > rice husk SiO2/ PU > precipitation SiO2/PU.For the same kind of SiO2,water absorption of composites increased with increasing of SiO2 content and temperature.For same SiO2 content,the water absorption of SiO2 / PU composite from low to high order was: rice SiO2 / PU < precipitation SiO2 / PU < gas phase SiO2 / PU.