巻号一覧
20 巻 (1992)
- 4 号 p. 165-
- 3 号 p. 109-
- 2 号 p. 51-
- 1 号 p. 4-
20 巻, 1 号
選択された号の論文の5件中1～5を表示しています
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南斎 征夫1992 年 20 巻 1 号 p. 4-17
発行日: 1992/03/20
公開日: 2012/11/20
ジャーナル フリーPost-yield plateau of a true-stress vs. strain relation for glassy polymethyl methacrylate (PMMA) is illustrated to be a state of steady flow. A novel rate analysis applied to this steady flow provided a unique functional relation between the activation energy ΔH and the activation entropy ΔS. This functional relation for the PMMA glass is demonstrated to agree with a function of ΔH vs. ΔS obtained from the relaxation data for the melt of the same PMMA sample. This agreement was also confirmed for polyvinyl chloride, polycarbonate and polystyrene, thus giving direct evidence verifying a change of the metastable glassy structure into a liquid-like structure in the polymer glasses. Hence, the yielding in the polymer glasses is convincingly concluded to be a transition phenomenon due to this structural change.抄録全体を表示PDF形式でダウンロード (2817K) -
-末端カルボキシル基を持つ樹脂の効果-小林 敏勝, 池田 承治, 尾崎 邦宏1992 年 20 巻 1 号 p. 18-24
発行日: 1992/03/20
公開日: 2012/11/20
ジャーナル フリーPigment dispersibility was studied for resins with various numbers of carboxyl groups at the chain end. The resins were synthesized by ring-opening polymerization of ε-caprolactone. G type resin had a carboxyl group at one end of each molecule. S type resin was a mixture of molecules with 0, 1 or 2 carboxyl groups at the end of molecules. P type resin was a tetra-functional resins terminated with carboxyl groups. L type resin was without carboxyl groups.
Dispersed pastes of Cu-phthalocyanine blue using G type resin revealed a higher degree of dispersion and a lower structural viscosity than pastes using S type resin. TiO2 dispersed pastes were prepared using mixtures of G type resin and L type resin at various mixing ratios. As the amount of G type resin increased, the degree of dispersion was enhanced and the yield value decreased. L type resin showed almost no effect on the yield values of TiO dispersed pastes. TiO2 dispersed pastes using P type resin showed a lower degree of dispersion and a higher structural viscosity than those using G type resin.
The resin molecules with no carboxyl groups did not affect the dispersibility or the structural viscosity of pigment dispersed pastes. The resin molecule with more than two carboxyl groups built up a structure among pigment particles and caused aggregation.抄録全体を表示PDF形式でダウンロード (1292K) -
根本 紀夫, 山村 武, 尾崎 邦宏1992 年 20 巻 1 号 p. 25-28
発行日: 1992/03/20
公開日: 2012/11/20
ジャーナル フリーViscoelastic and forced Rayleigh scattering measurements were made on mixtures of PS and PVME over the wide range of temperature and PS molecular weight. The temperature dependence of the tracer diffusion coefficient D of PS in PVME was well described by the shift factor aT obtained from time-temperature superposition of the dynamic shear modulus data of PVME in bulk. The dependence of D on PS molecular weight was described by the free-draining Rouse chain model in the low M region where the coil size of the diffusing PS chain is smaller than the mesh size of the PVME entanglement network. In the high M region, on the other hand, D did not decrease in proportion to M-2, being in disagreement with the prediction of the reptation model, but took a constant value nearly equal to the calculated Ds value of the PVME molecule in bulk at the high M end. Two conjectures were proposed for interpretation of the above anomalous diffusion behavior.抄録全体を表示PDF形式でダウンロード (874K) -
井上 良徳, 松岡 孝明, 高橋 秀郎1992 年 20 巻 1 号 p. 29-35
発行日: 1992/03/20
公開日: 2012/11/20
ジャーナル フリーIn injection molded parts made of fiber reinforced thermoplastics, large warpages are frequently observed. The warpage is caused by anisotropic mechanical properties yielded by fiber orientations in molded parts. Therefore, it is necessary to predict fiber orientations and anisotropic mechanical properties for estimating the occurrence of warpages.
A computer program for evaluating fiber orientation in molded parts was developed by using Folgar and Tucker's planar orientation model that was considered as fiber-fiber interactions. The classical laminated plate theory was applied to predict mechanical properties (elastic modulus and thermal expansion coefficient) of molded parts in this study. The mechanical properties were predicted in the analysis from calculated fiber orientations and mechanical properties of the fiber and the polymer.
Predicted elastic modulus and thermal expansion coefficient were compared with measured ones for a molded plate of glass-fiber-reinforced nylon-6, 6 (fiber content 30wt%) to verify computational method. Predicted results agreed with measured ones very well for both the elastic modulus and the thermal expansion coefficient.抄録全体を表示PDF形式でダウンロード (1201K) -
白崎 芳夫, 立石 哲也, 宮永 豊1992 年 20 巻 1 号 p. 36-39
発行日: 1992/03/20
公開日: 2012/11/20
ジャーナル フリーEffects of swimming and running trainings on mechanical properties of bone and bone density were investigated. Mechanical tests were conducted for tibial bone. The dynamic stiffness and tanδ were measured by a viscoelastic spectrometer. The three-point bending test was performed with an Instron-type universal testing machine. Bone mineral content was measured by photon-absorptiometry at the middle site of the tibial bone. In the swimming case the stiffness and tanδ were, in average, larger for the trained rats than for the controlled group. The strength and the bone density were also larger for the trained group. In the running case, the negative effects were observed on these variables.抄録全体を表示PDF形式でダウンロード (2856K)
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