Relations between microscopic crosslinking structure and heterogeneity of physical gels and macroscopic properties.

我们设计了一台红外光谱仪，用于测量凝胶或薄膜样品拉伸过程中10μm微观范围内的二色性，以观察分子对拉伸变形刺激的响应。测量了两种具有不同类型微晶交联区的聚乙烯凝胶的红外二向色性随拉伸的变化。一种是以四氢呋喃为溶剂溶胀薄膜制备的溶胀凝胶。另一种是通过加热膨胀凝胶而获得的溶液逐渐冷却而制备的溶液凝胶。溶胀凝胶的变形分两步进行，第一步凝胶由片层组成的交联区旋转变形，第二步凝胶通过拉伸取向结晶和非晶区。另一方面，溶液凝胶一步变形，晶区和非晶区通过伸长率同时取向。我们研究了聚丙烯FI-…的变形行为更多的球晶包括被微晶区包围的巨型球晶。随着拉伸的进行，微晶区大量取向，而巨型球晶几乎没有取向，与微晶区相比，球晶较硬。在微晶区，它在屈服现象结束前几乎保持无取向状态，在屈服点后迅速取向。然后，取向逐渐进行，进一步伸长。对于巨球晶区，在α晶体中，每束晶体都发生了片层的分离和纠缠。α_&lt；Mix&gt；晶体不容易变形，因为子晶片防止了母晶片的变形。β晶体是脆性的，扭曲片层的纠缠在较小的应力作用下很容易解缠。α晶体与微晶区相互隔离，而β晶体与微晶区的缠绕和球晶的变形对体系的变形有很大影响。较少

We designed an infrared spectrometer for dichroism measurement under microscopic scope of 10 μ m size during elongation of samples of gels or films in order to observe molecular motions responding to stimulus of elongational deformation.We measured infrared dichroism change with elongation for two types of polyethyelene gels with different type of crosslink regions of microcrystallite. One is a swelling gel prepared by swelling the film in tetralin as solvent. The other is a solution gel prepared by gradually cooling a solution obtained by heating the swelling gel. The swelling gel deformed by two steps ; In first step, gel deformed by the rotation of crosslink region consisting of lamellae, and in second step crystalline and non-crystalline regions were oriented by elongation. On the other hand, the solution gels deformed by One step, in which crystalline and non-crystalline regions were simultaneously oriented by elongation.We investigated the deformation behavior of polypropylene fi … More lm including giant spherulites surrounded by microcrystallite region. When elongation proceeded, microcrystallie region was oriented largely while the giant spherulites were scarcely oriented, which means that the spherulite is fairly rigid in comparison with the microcrystalline region. In the microcrystalline region, it almost keeps unoriented state before finishing yield phenomenon and rapidly oriented just after the yield point. And then the orientation gradually proceeded with further elongation. As for the giant spherulite region, in α_ crystals, separation and entanglement of lamellae occurred for each bundles of crystals. α_<mix> crystals did not easily deform because child lamellae prevent from deformation of parent lamellae. β crystal was fragile and entanglement of twisted lamella was easily disentangled by small stress. α crystals were fairly isolated from the microcrystalline region, while β crystals entangled with microcrystalline region and deformation of spherulite in largely influence to the deformation of the system. Less