Structure and water sorption of polyurethane nanocomposites based on organic and inorganic components
Structure and water sorption of polyurethane nanocomposites based on organic and inorganic components
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DOI：
10.1016/j.eurpolymj.2004.06.007
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发表时间：
2004-10
影响因子：
6
通讯作者：
Y. Mamunya;V. Shtompel’;E. Lebedev;P. Pissis;A. Kanapitsas;G. Boiteux
中科院分区：
文献类型：
--
作者：
Y. Mamunya;V. Shtompel’;E. Lebedev;P. Pissis;A. Kanapitsas;G. Boiteux
通过聚氨酯齐聚物与水溶液硅酸钠的共聚反应，制备了由聚氨酯有机相和无机相组成的有机-无机聚合物复合材料。复合材料的结构和形态，在一个固定的重量分数的无机组分的20%，和相应的纯聚氨酯矩阵进行了研究，通过广角和小角X射线散射（WAXS和SAXS，分别）。结果表明，由于无定形聚氨酯基质的刚性和柔性嵌段的微相分离以及由于无机结晶夹杂物，复合材料的非均匀性尺度的尺寸相似（5-7 nm），即所制备的材料是纳米复合材料。WAXS测量表明，嵌段无机组分的单独性质在纳米复合材料中丢失，可能是由于两种组分之间的物理和化学相互作用。从液相中的水的吸附进行了研究，重量分析在复合材料和相应的聚氨酯。结果表明，由于无机相的亲水性和聚氨酯基体的弹性，复合材料具有高的吸附能力，并允许估计吸附在无机纳米颗粒表面上的水的层厚度为约20 nm，与文献中采用的模型合理一致。WAXS和SAXS测量的溶胀的复合材料和溶胀和干燥的复合材料的无机组分的结构中的变化引起的水，这是，然而，在很大程度上是可逆的。这些材料可用作凝胶电解质和药物递送系统中的水凝胶。
Organic–inorganic polymer composites, consisting of a polyurethane organic phase and a mineral inorganic phase were prepared by the joint polymerization of the urethane oligomer with the water solution sodium silicate. The structure and the morphology of the composites, at a fixed weight fraction of the inorganic component of 20%, and of the corresponding pure polyurethane matrices were investigated by wide-angle and small-angle X-ray scattering (WAXS and SAXS, respectively). The results show similar size (5–7 nm) of the scale of heterogeneity of the composites due to the microphase separation of the rigid and the flexible blocks of the amorphous polyurethane matrix and due to the inorganic crystalline inclusions, i.e. the materials prepared are nanocomposites. The WAXS measurements indicate that the individual properties of the block inorganic component are lost in the nanocomposites, probably due to physical and chemical interactions between the two components. Water sorption from the liquid phase was studied gravimetrically in a composite and in the corresponding polyurethane. The results show high sorption capacity of the composite, due to the hydrophilicity of the inorganic phase and the elasticity of the polyurethane matrix, and allow to estimate the layer thickness of water adsorbed on the inorganic nanoparticle surface to about 20 nm, in reasonable agreement with a model adopted from the literature. WAXS and SAXS measurements on the swelled composite and the swelled-and-dried composite indicate changes in the structure of the inorganic component induced by water, which are, however, to a large extent reversible. These materials may find applications as gel electrolytes and as hydrogels in drug delivery systems.