Fatigue tests of glass fiber reinforced poly (butylene terephthalate) (PBT) composites were carried out at 303K. The composites of surface-modified glass fiber showed greater fatigue strength compared with that of surface-unmodified glass fiber. Scanning electron microscopic observation of the interface between glass fiber and polymer matrix revealed a remarkable influence of interfacial adhesion on fatigue strength of the composites.
Morphology of the slip deformation bands is examined in a scanning electron microscope, which are formed by redrawing the uniaxially drawn and then notched high-density polyethylene films at various angles with the initial draw direction. The morphological difference between the slip band region and the uniaxially drawn area is easily distinguishable after treatment with low-temperature oxygen plasma, which produces the layer structure on the surface of the specimen.
Poly (ethylene terephthalate) (PET), nylon 6, and p-aramid films were sputter-etched with argon ions at a pressure of 0.1mmHg and their surfaces were examined by scanning electron microscopy. The uniaxially stretched PET and nylon 6 films showed a number of wavy crevices perpendicular to the stretching direction, whereas biaxially stretched PET and nylon 6 films produced many protrusions. Casted p-aramid film also produced the same protrusions.
Morphological change in a product from p-aminohippuric acid monomer single crystal through the thermal solid state polycondensation reaction at 170°C up to 1200h is observed mainly by means of scanning electron microscopy. In the early stage of the polymerization process (100-200h), many rectangular prisms ca. 5μm long are observed on the surface of the specimen. A needle-shaped or fibrillar material is formed after the polymerization for ca. 250h. It is found that the surface of the specimen is finally covered with the microfibrils ca. 100nm in diameter.
For carbons derived from polyoxadiazole, the effects of macroscopic geometry of starting materials on the formation of microtextures of resulting carbons have been studied in relation with processing factors by scanning electron microscopy.
A cryogenic transmission electron microscope with a superconducting objective lens was utilized to obtain high-resolution images of uniaxially oriented thin films of polyethylene and isotactic poly-(4-methyl-1-pentene). The resulting images successfully revealed the presence of tie-crystallites connecting crystalline lamellae in the stretching direction in both of the films.
The degree of dispersion of carbon black (CB) particles in a polymer matrix is known to be a determining factor in the physical properties of the composites. In this study, we discuss the effect of the oxidation treatment of CB, the chemical modification of the chain-ends and main chain of the polymers and molding time on this dispersion in detail, through a study using scanning electron microscopy (SEM) observation. The oxidation of CB changed the state of its distribution in some polymer matrices: in a nonpolar polymer the fillers was aggregated, but, in a polar polymer the dispersion of the fillers was improved. The chemical modification of chain-ends causes a regular distribution of CB particles, but the chemical modification of the main chain caused the CB particles to be aggregated. Also, this distribution state was changed in accordance with the molding time.
Fine particles observed in the emulsion particles of poly (vinylidene fluoride) [PVDF] were morphologically discussed. From the TEM observation of surface replica of the emulsion particles and of the particles dispersed by stirring in liquid N2, it was concluded that the emulsion particles were consisted of fine particles of 20-30nm in diameter. In the fracture surface of PVDF sheets which were melted and then compression-molded, fine particles of 20-30nm in diameter were also observed depending on the annealing conditions.
A plasma-induced polymerized naphthalene (PPN) film for the use of a replica method coupled with transmission electron microscopy (TEM) was studied in order to visualize the surface microstructures of various organic and inoraganic materials such as trenched silicon wafers and Langmuir-Blodgett (LB) films. As a result, we found that each PPN film examined had its smooth surface on the electron microscopic scale. We were able to visualize the surface microstructures of various materials.
Morphological changes of wool, silk, cotton and rayon fabrics exposed to NO2 gas and the ambient air were observed by the electron microscope. Both the samples exposed to 100ppm NO2 gas for 100h and to the ambient air for 18 months showed the changes on the fiber surfaces which could be recognized under the electron microscope. Cellulosic fibers are more damaged by NO2 gas than protein fibers. The difference would be connected with the existance of the amino groups in the protein fibers.
The far-ultraviolet excimer laser ablation of epoxy resin has been investigated by morphological observation with a scanning electron microscope. The first stage of the ablation is the occurrence of a rough surface. The second stage is a formation of granular structure, accompanying their growth into particles. The third stage is an increase in particle size.
Band structure found in a shear-deformed HPC film from its mesophase in acetic acid solution was observed by a polarized optical and a scanning electron microscope. The scanning electron microscopic observation revealed the band structure being constructed with a pile of pleated sheets or bundles of the narrow films which oriented in one direction in each band but turned the direction in the neighbor bands in a zigzag manner.
The crystal structure of a series of model compounds of liquid-crystalline arylate polymers, C2H5-OCO-φ-OCO-φn-COO-φ-COO-C2H5 (n=1, 2, and 3), was studied by electron diffraction. All observed reflections could be indexed based on the b*-c′* reciprocal lattice plane with nearly same unit-cell parameters. Based on these data combined with the previously reported X-ray powder patterns and infrared and Raman spectra, the isomorphism of the n1, n2 (β form) and n3 crystals was confirmed.
Liquid crystalline properties for copoly (ethylene terephthalate/chloro-1, 4-phenylene terephthalate) have been investigated. The polymer was highly sensitive to shear stress and revealed nematic liquid crystal structure at a composition of more than 20 mole% of chlorophenylene terephthalate (CPT). The liquid crystallinity increased with the increase in CPT content and inherent viscosity of the copolymer.
Thermal behaviour of photoreactive amphiphilic diolefin, monodecyl p-phenylenediacrylate, was investigated by polarizing microscopy and differential scanning calorimetry. The remarkable changes in appearance of the crystal was observed at 82.7°C up to 99.4°C. The crystal showed liquid crystalline state between the temperature of 177°C and 184°C.
The present work is to clarify the fine structure of hair fiber components, especially Cell Membrane Complex (CMC) of cuticle. Hair fibers were treated with either hydrophilic N-acetylcysteine (NAC), thioglycolic acid (TGA) or hydrophobic tri-n-butyl-phosphine (TBP) for disulfide bond (SS) reduction. It was confirmed that the sulfhydryl residues (R-SH) were mainly produced in the CMC region by the initial reduction, being observed fluorescent from R-SH after labelled with N-(7-dimethylamino-4-coumarinyl)-maleimide (DACM). These reduced fibers were grafted with methyl methacrylate (MMA) by using lithium bromide and potassium persulfate system. The location of the grafted polymer in the fiber was determined as a low electron density region by a high resolution transmission electron microscopy. The grafted polymer was mainly observed in the CMC and the endocuticle of the TGA-reduced fiber, but not in that of the TBP-reduced fiber. Especially a homogeneous unstained layer was found in the middle region of the δ-layer of cuticle CMC of TGA-reduced hair. When hairs were prefixed with ruthenium tetroxide instead of osmium tetroxide, a structural change of the δ-layer to lamella-like structure were observed in the CMC of cuticle without graft copolymerization. These results suggest that the CMC consists of not only relatively hydrophilic regions containing SS linkages which the reduction brings about a large space for polymer uptake but hydrophobic lamella-like lipid layers.
Structural changes of ultra-high molecular weight polyethylene during drawing were dynamically studied using an X-ray TV system and an X-ray recording system with imaging plates. At an early stage of drawing at temperatures below about 80°C, monoclinic phase occurred. By drawing at higher temperatures, highly oriented polyethylene was obtained without producing the monoclinic phase even in a transient state.
The thermosol dyeing of poly phenylene sulphide and poly ether-ether ketone fibers was possible at the temperatures above the cold crystallization temperature of polymers. The tensile strength of fibers heat-treated at the dyeing temperature in the air was identical to that of original fibers.
The orientation of bacterial cellulose was achieved by stirred culture. The fibrils showed higher orientation than those produced by conventional static culture, The oriented membrane became clear during the drying and the replacement of water retained in fibrils to organic solvents made the orientation of fibrils clearer under polarized microscopy.
The blend gels of konjac mannan and hydroxypropyl cellulose (HPC) were prepared. The solid films were prepared from the blend gels by three kinds of processes. The textures of the films were observed by scanning electron microscopy. The textures depended on the process and konjac mannan seemed to have an affinity to HPC.