A New Model for Structure of Poly (ethylene terephthalate) in its Glassy State

A new realistic, structural model is proposed for the glassy solid state of poly(ethylene terephthalate) (PET). The model is considered basing on crystallization behaviors from the glassy state of PET, and in particular including the evidence from the estimation of chain folding energy in this report. When PET is quenched from its melt into the glassy state, irregular folds with lower conformational energy remain in glassy structure and disturb the three dimensional arrangement of the chains connected with the folds. In conclusion, we suggested that the structure of glassy PET is not in amorphous state which is represented by the interpenetrating random coil model, but in frozen metastable state which can be approached from the chain folded structure of polymer crystals

Efficient semiclassical quantization methods : Combination of the AFC-II theory and cellularized dynamics(4) Quantum chaos and semiclassical theory in molecular science and nuclear theory, Chaos and Nonlinear Dynamics in Quantum-Mechanical and Macroscopic Systems)

この論文は国立情報学研究所の電子図書館事業により電子化されました。本研究では、AFC-II理論とセル化の手続きを組み合わせて効率的な半古典量子化の方法を導入する。この方法で得られたスペクトルを古典トラジェクトリーに基づき解析する。さらに、AFC-IIの公式はセル化の手続きによっても導くことが可能であることを示す。この証明によって、AFC-II理論を初期運動量を持つトラジェクトリーにまで拡張することが可能である。また、異なる初期運動量を持つトラジェクトリー間の干渉の効果を議論する。We propose new efficient semiclassical quantization methods, which are combinations of the amplitudefree correlation function II(AFC-II) theory and cellularized dynamics. We analyze the semiclassical spectra obtained here by using the classical trajectory. In addition, we show that the AFC-II formulation can be derived by the celluarization procedure. Using this derivation, we can extend the AFC-II theory straightforwardly in order to quantize the non-zero initial momentum trajectories. We demonstrate that the extended AFC-II quantization is successful. We also discuss the effect of the interference between the different, initial momentum traifectories

Giant Single Crystals of Poly (ethylene oxide)

The preparative method of giant single crystals of PEO and the experimental results of them by x-ray diffraction and electron microscopy are described. The crystallization of PEO was carried out in a two dimensional crystallization apparatus. From the tridirectional x-ray diffraction patterns on the resulting platelike crystals, it was confirmed that these crystals have a single crystal-like orientation at high supercoolings, the [401] axis is parallel to a growing direction and the [001] axis is perpendicular to the wide surface, and a double orientation at low supercoolings, two axes of [421] and [421] are parallel to a growing direction and the [001] axis is perpendicular to the wide surface

The Molecular Mechanism of Chain Tilt in Poly (ethylene terephthalate) Fibers

The molecular mechanism of chain tilt in poly(ethylene terephthalate) (PET) fibers was proposed. The mechanism was considered basing on the ordering process from the cold drawn state of glassy PET. It was confirmed that the direction of maximum contraction on ordering agrees with the azimuth of chain tilt which varies with annealing temperature. In the stacking structure of irregular folded chain blocks of cold drawn PET, the expansion to the chain direction and the contraction to the lateral direction yield the compressive stress and tensile stress r respectively. The stress revealed as the result of the ordering from the glassy structure to crystalline structure can be relaxed by the rotation of the resulting crystallites. Therefore, we can suggest that the chain tilt is caused by the relaxation process of the stress

Polymorphism of Amylose V Complexes

Lamellar crystals of amylose V complexes with the 6(1), 7(1) and 8(1) helical configurations can be prepared from aqueous solutions of amylose by using various complexing agents. It is noted that the crystal shape can be explained by the symmetry of the unit cell in the basal plane and the chain packing in the unit cell is cOncerned with the symmetry of helical chains. The existence of 6(1), 7(1) and 8(1) heliccs which occurs stepwisc with the number of glucopyranose an intger is discussed