Small-Angle Neutron Scattering of a Solvent-Swollen Segmented Polyurethane as a Probe of Solvent Distribution and Polymer Domain Composition
Small-Angle Neutron Scattering of a Solvent-Swollen Segmented Polyurethane as a Probe of Solvent Distribution and Polymer Domain Composition
复制标题
DOI：
10.1021/ma800015g
复制
发表时间：
2008-05
期刊：
影响因子：
5.5
通讯作者：
J. Mang;R. Hjelm;E. B. Orler;D. A. Wrobleski
中科院分区：
文献类型：
--
作者：
J. Mang;R. Hjelm;E. B. Orler;D. A. Wrobleski
嵌段聚氨酯由交替的刚性芳族（硬）和柔性（软）链段组成，所述链段相分离成富含硬链段和软链段的纳米域。域结构导致被认为是扩展的交联网络，赋予这些材料独特的机械性能。由于不连续相的对比度和体积分数差，先前的散射研究集中在硬段含量大于30重量%的聚氨酯上。该研究集中于仅含有23wt%硬段含量的商业聚酯氨基甲酸酯Estane 5703。为了探测畴结构和组成，我们使用小角中子散射（SANS）和对比度变化方法对用苯、甲苯或邻、间或对二甲苯异构体的氘化/质子化混合物溶胀的大块样品进行了测量。我们使用流体模型和Pedersen的胶束模型来描述SANS数据作为对比度的函数。流体模型和胶束模型都把Estane看作球形流体。
Segmented polyurethanes consist of alternating rigid aromatic (hard) and flexible (soft) segments that phase separate into hard and soft segment-rich nanodomains. The domain structure results in what has been presumed to be an extended, cross-linked network, giving these materials unique mechanical properties. Because of poor contrast and volume fractions of the discontinuous phase, previous scattering studies have focused on polyurethanes with hard segment contents greater that 30 wt %. This study focused on a commercial poly(ester urethane), Estane 5703, containing only 23 wt % hard segment content. To probe the domain structure and composition, we used small-angle neutron scattering (SANS) with contrast variation methods on bulk samples swollen with deuterated/protonated mixtures of benzene, toluene, or o-, m-, or p-xylene isomers. We used the fluid model and Pedersen’s micelle model to describe the SANS data as a function of contrast. Both the fluid and micelle models consider Estane as a fluid of sph...