Dynamic X-Ray Diffraction Technique for Measuring the Crystal Lattice Response in Semicrystalline Polymers against Mechanical Excitations

Dynamic mechanical and crystallographic features which are associated with mechanical excitations on the bulk specimen of the semicrystalline polymers are generalized on the basis of factors such as mechanical dispersions of orientation of crystallites and deformation of the crystal superstructure. The latter factor may further be divided into inter-lamellae and intra-lamella responses within the superstructure such as spherulite. The present paper describes the theory and techniques set up to observe the intralamella response in the semicrystalline polymers against mechanical excitations by means of a dynamic x-ray diffraction technique. This observation is required to measure the inphase and out-of-phase components of the angular vibration of the diffraction maximum raised by the forced sinusoidal strain of the test specimen. For this purpose, it was shown that a twin detector technique could successfnlly be applicable where the diffraction peak shift was amplified by simultaneous measurements of the shoulder intensities of the diffraction perk at the higher and the lower diffraction angles to the peak maximum

Dynamic X-ray Diffraction Technique for Measuring Rheo-optical Properties of Crystalline Polymeric Materials

A dynamic X-ray diffraction technique, which can follow the responses of polymer crystals (crystallization, orientation, and lattice deformation) to a mechanical excitation of sinusoidal strain induced to a bulk specimen, was described. The descriptions for such responses are qualitatively made by using a narrow sector technique, which can measure the X-ray diffraction intensity distribution at a particular phase angle of the sinusoidal strain as a function of static and dynamic strains, temperature, and angular frequency. A typical result is demonstrated in terms of the investigation of orientationcrystallization phenomena of natural rubber vulcanizates. More quantitative descriptions can be made by using a half-circle sector technique, which can measure the in-phase and out-of phase components of the dynamic X-ray diffraction intensity distribution. From these, one can obtain the dynamic strain-induced crystallization and orientation coefficients and the dynamic response of lattice deformation of a specific crystal plane both as functions of temperature and frequency. After a brief survey of the principle of the half-circle sector technique, frequency dependence of the dynamic strain-induced crystallization coefficients of the (002) and (200) crystal planes of natural rubber vulcanizates is demonstrated in terms of the two frequency dispersion regions around 10⁻² and 10¹ Hz at a room temperature. The former and latter dispersions must be correlated with the crystallization processes of the so-called α- and γ-filaments, respectively. In addition, frequency and temperature dispersions of the dynamic strain-induced orientation coefficient and the dynamic response of lattice deformation of the (110) crystal plane of polyethylene are demonstrated in relation to the so-called a₁ and a₂ dispersions of dynamic mechanical modulus function of this material

ケッショウセイコウブンシノリュウドウコウガクテキソクテイノタメノドウテキXセンカイセツホウ

京都大学0048新制・課程博士工学博士甲第2148号工博第591号新制||工||423(附属図書館)5746UT51-55-L486京都大学大学院工学研究科高分子化学専攻(主査)教授 河合 弘廸, 教授 小野木 重治, 教授 西島 安則学位規則第5条第1項該当Kyoto UniversityDA

Radiation Damage Effect by 25MeV Protons on Thallium Bromide Nuclear Radiation Detectors

開始ページ、終了ページ: 冊子体のページ付