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Microhardness Studies of the Interphase Boundary in Rubber-Softened Glassy Polymer Blends Prepared with/without Compatibilizer

 M. F. Mina, M. E. Haque, F. J. Balta Calleja, T. Asano and M. M. Alam


Micromechanical Behavior and Glass Transition Temperature of Poly (methyl methacrylate)/Rubber Blend

M. F. Mina, F. Ania, T. A. Huy, G. H. Michler and F. J. Balta Calleja


Optimization of Synthesis and Characterization of Acrylamide Hydrogel by γ-ray Irradiation

M. A. Chowdhury, M. M. Alam, M. F. Mina, F. Akthar and S. E. Kabir


Thermal and X-ray Measurements on n-Hexatriacontane

M. F. Mina, T. Asano, B. Poirier, D. Mondieig, A. Wuerflinger and C. Josefiak


Microhardness Studies of PMMA/Natural Rubber Blends

M. F. Mina, F. Ania, F.J. Balta Calleja and T. Asano


Effect of Monomers in the Structural Modification of Natural Rubber during γ-Ray Irradiation

M. F. Mina, T. Asano, N. C. Dafader, F. Akthar, S. Yoshida, N. Tohyama, K. Imaizumi


Effect of SBS Compatibilzer on the Interphase Boundary of Polymer Blends of Polystyrene and Natural Rubber

M. Boyonova, M. F. Mina, F.J. Balta Calleja and S. Fakirov


Effect of Gamma Rays in the Preparation of Polymer and Hydrogel from Acrylamide Monomer

M. M. Alam, M. F. Mina, F. Akthar


Swelling and Hydration Properties of Acrylamide Hydrogel in Distilled Water

M. M. Alam, M. F. Mina and F. Akthar


Centrifuging Effect on the Structure and Property of Natural Rubber Latex Films

 M. F. Mina, M. M. Alam, F. Akthar, S. Yoshida, N. Tohyama, K. Imaizumi and T. Asano


Studies of γ-Ray Induced Polymerization of Aqueous Acrylamide

M. M. Alam, F. Akthar, M. F. Mina, N. C. Dafader and A. I. Mustafa


Crystallization of a low molecular weight Polyethylene and Paraffins under a Temperature Gradient

T. Asano, M. F. Mina, A. Nishida, S. Yoshida and Y. Fujiwara


Crystallization of Oriented Amorphous Poly(ethylene terephthalate) as Revealed by X-Ray Diffraction and Microhardness

T. Asano, F. J. Balta Calleja, A. Flores, M. Tanigaki, M. F. Mina, C. Sawatari, H. Itagaki, H. Takahashi and I. Hatta


The structural changes occurring when amorphous cold-drawn poly(ethylene terephthalate) films are annealed at different temperatures (50°C–240°C) for different annealing times (10–104 s) were investigated by means of X-ray diffraction and microhardness techniques. The X-ray results reveal the appearance of smectic order at 60°C with a period of 10.7 Å. At 70°C, a layer structure in the scale of 110 Å emerges. Finally, triclinic order is observed above 80°C. The appearance of a layer structure prior to the development of triclinic crystals is associated with a density difference along the molecular direction produced by a molecular tilting mechanism. The microhardness behaviour of annealed cold-drawn PET films is correlated to the developing morphologies. At high annealing temperatures (>100°C), the plastic component of hardness is shown to vary with the occurring microstructural changes. Results indicate that the hardness of the amorphous intrafibrilar regions is higher than that of a fully amorphous material. The indentation anisotropy, ΔH, which is related to the elastic recovery of the material shows a conspicuous decrease at Ta∽70°C, which is explained in terms of a relaxation of the fibrils in the chain direction.

Melting Behavior of the Oriented β-phase Polypropylene Texture Crystallized by the Temperature Slope Method

 T. Asano, Y. Yamamoto, M. F. Mina, Y. Fujiwara, H. Takahashi and I. Hatta


Isotactic polypropylene consisting of uniaxially oriented P-phase lamellae was crystallized in a temperature gradient. The β → α transition was investigated by simultaneous measurements with differential scanning calorimetry (DSC) and X-ray diffraction using synchrotron radiation (SR). To compare the transition mechanism, the β-phase sample was deformed by rolling it along the direction of the crystallization. During rolling, the β-crystal is deformed by interlamellar and interchain slip, which induces c-axis-oriented molecules along the rolling direction. The melting behavior is changed by the rolling deformation. For the as-grown β-crystal, the DSC thermogram has three peaks: the β-melting endotherm at 150°C, an exotherm by recrystallization into the °-form, and the endotherm at 167°C caused by melting of the recrystallized α-form. After the rolling deformation, the β-endotherm is extinguished by the successive exotherm. Simultaneous X-ray measurements reveal that the β → α transition is shifted to a lower temperature and that the recrystallized α-form has a c-axis-orientation caused by the rolling deformation. In the process of the β→ α transition, higher-order lamellar structure is developed earlier than formation of the crystalline structure. In this study, the heating phenomena, such as the β α transition and thickening of the β- and α-lamellae, are consistently explained by a mechanism involving melting and subsequent recrystallization.

Effect of Homologous Impurity on the Solid-Solid Phase Transition of Normal-Alkane (Hexatriacontane) Crystal Studied by Time-Resolved X-Ray Measurements

M. F. Mina, T. Asano, R. Nuryadi, C. Sawatari, H. Takahashi and I. Hatta


Dynamic Investigation of the Solid-Solid Phase Transition of Normal-Alkane (Hexatriacontane) by Simultaneous Measurement with Differential Scanning Calorimetry, Small-Angle X-ray Scattering and X-ray Television Detector

M. F. Mina, T. Asano, H. Takahashi, I. Hatta, K. Ito and Y. Amemiya


Simultaneous measurements have been performed using differential scanning calorimetry, time-resolved small-angle X-ray scattering and X-ray television (TV) methods to study the solid-solid phase transition of the normal-alkane (hexatriacontane) single crystal. The low-temperature monoclinic form (M L) of hexatriacontane transforms to the high-temperature monoclinic form (MH) by two mechanisms. One mechanism is a direct transition from M L to M H by twin formation without passing any activated state. The other mechanism is a two-step transition through an intermediate orthorhombic state (O), where the molecules stand up from the M L state and then re-incline into the M H state. The subsecond time-resolved investigation by simultaneous measurements reveals dynamic variations during the transition. The former M L→M H transition appears at a lower temperature showing that twin formation requires lower energy, than the two-step process with the activated state. Continuous changing of intensities observed in the X-ray TV indicates that the latter M L→O→M H transition is caused by the coherent motion of the molecules.

Twin Formation Mechanism in the Solid-Solid Phase Transition of Normal Hexatriacontane (n-C36H74) 

T. Asano, M. F. Mina and I. Hatta


Solid-solid phase transition of -C 36 74 was investigated by DSC and X-ray diffraction methods. In the original monoclinic single crystal, molecular chains inclined about 27° in the bc -plane from the normal to the lamellar surface. During the transition started from 72°C and completed at 73.4°C, two kinds of mechanisms were observed in the formation of a high temperature monoclinic structure having the molecules inclined about 19° in the ac -plane. One mechanism was due to formation of twinned crystals where the transition was developed on the frontier of the (110) twin boundary. The twin formation was achieved by rotation of the molecular zigzag plane producing the new crystalline -axis deviated by 67° from the original orientation. The other mechanism was attained by changing the molecular staggering by 90° where the crystalline axis was unchanged. In the solid-solid transition, the two mechanisms appeared simultaneously, resulting in the appearance of polycrystals.

Physics Part I and II, Text Books for Higher Secondary Education, Approved by NCTB

T. Asano, M. F. Mina and Y. Fujiwara


The Use of Oil Palm Biomass (OPB) Fibers as reinforcement in Composites", In: Biofiber reinforcements in composite materials, Ed. Omar Faruk and Mohini Sain, UK, Woodhead Publishing Limited

M. D. H. Beg, M. F. Mina, R. M. Yunus and A. K. M. Moshiul Alam


A Survey of Polymer Crystallization by X-ray Diffraction,

T. Asano, M. F. Mina and Y. Fujiwara


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