Blend fibers of polypropylene (PP) and polystyrene (PS) have been produced by the melt spinning method over the wide range of the blending ratio at 220-257°C. The ultra-fine fibril formation and spinnability were studied.
The following results were obtained.
(1) Shear viscosity of PP was identical with PS at 230°C, despite the change in shear stress. PS was more viscous than PP at below 230°C and PS was less viscous than PP at above 230°C.
(2) Characteristic double sea/island texture was observed by electron microscopy in the 50/50 (PP/PS) blend formed at 230°C. However, at above or below 230°C, the more viscous component always formed the dispersed phase.
(3) When the filament was spun at a given temperature, the minor component formed the dispersed phase, even when the shear viscosities of the two components were different.
(4) Electron micrographs showed that PP fibrils in 20/80 blend fiber extruded at below 230°C were deformed less than PS matrix. The PP fibrils were deformed more than the matrix, however, at above 230°C.
(5) For the 20/80 blend fibers obtained at take-up speeds, 500 and 3500m/min, the average diameters of the ultra-fine fibrils were 550 and 400Å, respectively, and the average fibril lengths were estimated to be 2 and 4cm, respectively.
(6) At 230°C spinnability was good, regardless of the shear viscosity of the blends. Moreover, the spinnability of 10-20% blends was found to be better than that of homopolymers.

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The preoriented isotactic polypropylene (iPP) film, which was prepared by drawing and annealing, was redrawn at the angles of α (α=0, 30, 45 and 60°) to the preoriented direction (named the first draw direction FDD). By high redrawing, the preoriented iPP films were highly reoriented to the redrawing direction (named the second draw direction SDD). The films had the high crystal and amorphous orientation factors; such as f_c=0.992 and f_am=0.714. The dependence of T_m on DSC scan speed was examined and it was found that the degree of superheating increased with f_am. A history of the preorientation remained in the highly redrawn films and it appeared during thermal shrinkage at higher temperatures.

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Many transverse lines, which are alternations of optically bright and dark lines, are developed in highly drawn poly (ethylene terephthalate) (PET) filaments. In this report, the changes in the transverse lines upon hot drawing and with heat-treatment and/or alkali-treatment are examined with a polarizing microscope (POM) and a scanning electron microscope (SEM), and are discussed in relation to the deformation mechanism of the fiber. The transverse lines suddenly develop at certain draw ratio and become more and more distinct with further drawing, but very little change occurs in their number per 1μ. Though the surface undulation like the transverse lines is also observed with SEM in these highly drawn samples, its number is about three times that of the transverse lines observed with POM. Moreover, the transverse lines become faint or disappear with heat-treatment, but the surface undulation does not. It is found that there is some difference between these two kinds of transverse lines though they may be produced for similar reasons. When the highly drawn samples are alkali-treated, the surface undulation become explicit, and fibrillar structure can be observed in the concave parts of the alkali-treated surface. Those concave parts shrink more with heat-treatment in the free state than the convex parts of the alkali-treated sample. It is inconceivable that the transverse lines are fissures, since they become faint temporarily by stretching beyond the primary yield point at room temperature. The PET filaments having various surface appearances can be obtained with the combinations of drawing and alkali-treatment.

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Ethylene-vinyl acetate copolymer (EVAc) with 63.09% vinyl acetate content, was saponified heterogeneously in a methanol and water mixture using an alkali catalysis. A sharp boundary between reacted (EVA) and unreacted (EVAc) layer was observed by microscopy in the cross section of membrane, which taken out in the course of saponification and dyed with Rodamine 6G. The thickness of reacted layer changed in the same manner as the degree of reaction with the reaction time. After the extraction of the unreacted layer with solvent, vinyl acetate group was hardly observed in reacted layer by infrared analysis. The rate of advance of the boundary front was identical with that of transport of alkali ion into the polymer, however, the diffusibility of alkali ion into the saponified layer was extremely greater than the rate of advance of boundary front. From above results, it was found that the alkaline saponification of EVAc in heterogeneous system was controlled by the mechanism of boundary reaction which was similar to the Case II type diffusion.

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Diffusion of H₂O in poly (γ-methyl L-glutamate) (PMLG) membrane was examined through the hydrogen exchange reaction of active hydrogen (-NH) of PMLG by D₂O. α-Helical PMLG (α-PMLG) membrane cast from its solution in α-helical solvent and partially β-coiled PMLG (β-PMLG) membrane prepared by treatment of α-PMLG with formic acid were used as samples.
From the diffusion coefficient of H₂O at 30°C, the α-PMLG membrane should be equibrated within one minute. However, the deuteration of the membrane was not equibrated even in thousands of hours at 60°C. At above 100°C, the active hydrogens in the membrane, even when it was stretched two times, were deuterated completely. The deuteration rate followed a logarithmic relation between the degree of deuteration and reaction time, which had been suggested for a reaction in micell. These results showed that H₂O (or D₂O) diffused in the helix assembly and reacted with the active hydrogens in the α-helix at an extremely slow rate by breaking the hydrogen bonds. In the case of deuteration of β-PMLG membrane, the logarithmic relation had two stages, depending on the hydration of β-coiled chains and α-helical chains. Active hydrogen in the side chain of poly (γ-L-glutamic acid) (PLGA) membrane obtained by saponification of α-PMLG was deuterated completely within one hour, but the deuteration rate of the active hydrogen in main chain (in helix) was extremely slow as in the case of α-PMLG. These results showed that the diffusion of H₂O in the PMLG membrane advanced in two types of diffusion, one through the region of the side chains and the other through the hydration of peptide bonds.

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The effects of tannic acid on the diffusion behaviors of 18 kinds of disperse, acid and basic dyes in nylon 6 films were studied by the film roll method using a dyebath of pH 4.2 and 6.1 at 70°C.
Both the content of surface dye adsorption, C_s, and extrapolated value of diffusion coefficient to zero concentration of dye in the film, D_o, of disperse dyes decreased slightly with increasing in tannic acid content of the film, however, C_s and D_o were scarcely affected by change in pH of dyebath. For acid dyes, C_s and D_o decreased markedly as tannic acid content in the film and pH of dyebath increased.
The decreases in C_s and D_o were observed remarkably when dyes involved two or mor sulfonic acid groups, which indicated that those dyes is expected to be fixed more effectively by tannic acid treatment.
These decreases may be attributed mainly to electrostatic repulsion between the dye anion and the dissociated phenolic hydroxyl groups of tannic acid. On the other hand, C_s of basic dyes increased and D_o decreased by tannic acid treatment. These changes in C_s and D_o are due to the electrostatic attraction between the dye cation and tannic acid.
From these results, it seemed that the electrostatic interaction between dye and tannic acid adsorbed in nylon plays an important role in the dye fixation.

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