X-ray Studies on the Mechanical Behavior of Polymer Crystals

用X射线衍射法研究了各种聚合物晶区的弹性模量及其温度依赖性（从低温到高温）。比较了晶体模量与宏观形变及晶区分子运动的关系。所研究的聚合物如下：纤维素、纤维素三酯、甲壳素、壳聚糖、聚羟基苯甲酸/聚聚对苯二甲酸乙二醇酯共聚物聚萘二甲酸乙二醇酯聚萘二甲酸丁二醇酯（对亚苯基苯并双噻唑），聚（对亚苯基苯并二恶唑），热塑性聚酰亚胺，联苯型聚酰亚胺，Kapton型聚酰亚胺，三苯基型聚酰亚胺，ridid棒状聚酰亚胺，间规聚丙烯、乙烯-乙烯醇共聚物、等规聚乙烯醇、聚乙烯等，晶体模量给出了链分子的伸展性、晶格中的变形机制、可达到的最大模量等信息。在一定温度下，大部分聚合物的结晶模量降低，这是由于链分子在晶格中的运动增强。热膨胀系数在该温度附近突然变化，这也与观察到机械分散（所谓的晶体分散）的温度范围相吻合。

Elastic moduli of the crystalline regions of various kinds of polymers and their temperature dependence (from low to high temperature) were investigated by x-ray diffraction. Comparison were made between the crystal modulus with the macroscopic deformation and molecular motions of the chains in the crystalline regions. The investigated polymers were as follows : cellulose, cellulose triesters, chitin, chitosan, poly (hydroxybenzoic acid) /poly (ethylene terephthalate) copolymer, poly (ethylene naphthalate) , poly (butylene naphthalate) , poly (p-phenylene benzobisthiazole) , poly (p-phenylene benzobisoxazole) , thermoplastic polyimide, biphenyl type polyimide, Kapton type polyimide, triphenyl type polyimide, ridid rod-like polyimide, syndiotactic polypropylene, ethylene-vinyl alcohol copolymer, isotactic polyvinyl alcohol, polyethylene.The crystal modulus gives the informaton on the extensivity of the chain molecule, the deformation mechanism in the crystal lattice, the maximum attainable modulus. The crystal modulus decreased at a certain temperature for most of polymers, where the molecular motion of the chain molecules in the crystal lattice enhanced. The thermal expansion coefficient changed abruptly around that temperature, which also coincided with the temperature range where the mechanical dispesion, so-called crystal dispersion, was observed.