The effects of molecular weight on melt spinning and drawing process of PEEK (Poly (oxy-1, 4 phenyleneoxy-1, 4 phenylene carbonyl-1, 4 phenylene) were investigated. Spinnability, drawability, crystallinity, orientation and mechanical properties were measured for fibers prepared from three different molecular weight PEEK. With increasing molecular weight, crystallization rate for unoriented fibers decreased, whereas that for oriented fibers with the draw ratio higher than 1.5 increased. This result relates to the occurrence of the strain-induced crystallization in the spinning of high molecular weight PEEK. The crystallization raised the spinline tension and caused cohesive fracture of the spinline at a high melt draw ratio. Thus, the maximum melt draw ratio for high molecular weight PEEK was lower than that for low molecular weight one. On the other hand, drawability in the drawing process was better for high molecular weight PEEK, since crystallization rate was low at the early stage of the drawing and the formation of spherulites and voids did not proceed to a great extent. Consequently, crystallinity, molecular orientation and mechanical properties for high molecular weight maximally drawn fibers were higher than those for lower molecular weight ones.

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Changes in fine structures and chemical structures on the surface of poly (ethylene terephthalate) (PFT) fibers, caused by irradiation with excimer laser, were investigated. The SEM observation showed that the undrawn yarns suffered from ablation on the whole surface. while in the cause of drawn yarns, fine wavy shapes were formed perpendicular to the fiber axes. It has been revealed that the regular wavy shapes have close relations to fiber orientation, but not to the ratio of crystalline to non-crystalline region in the PET fibers. The XPS analysis of the fiber surface showed that for both undrawn and drawn yarns, the intensity ratios of O;_ls/C;_ls were reduced, that is, the contents of oxygen were reduced. The FT-IR analysis suggests that the dissociation of ester linkages occured simultaneously, and that the surface layer of the drawn yarns was converted to non-crystalline form.

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Commercial nylon 66 fibers were dipped in a chloroform solution of dicumyl peroxide (DCP) or benzoyl peroxide (BPO) at 60_??_65°C under N₂ atmosphere for predetermined times and then crosslinked at 150°C for 2h. The crosslinked fibers became partially insoluble in hot formic acid after dipping for 5 days for DCP and 3 days for BPO. By this crosslinking treatment the crystalline region was also affected. Reduced specific viscosity of crosslinked fibers decreased with the increase in crosslinking temperature and time of dipping, showing that the crosslinking of molecular chains occurred abreast with decomposition of main chains. Density and Young's modulus of crosslinked fibers increased, but tenacity and elongation decreased with the increase in time of dipping. The degrees of these increases and decreases were more remarkable for BPO than DCP.

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Effect of silane coupling treatment of glass fibers on mechanical properties of single-laminate epoxy resin reinforced with plain-woven glass fabric was studied. The microfracture along transverse fibers during tensile test was recorded on a video recorder and analyzed with image processing. In order to examine the effect of interfacial reinforcement on the initial microfracture stress and strain, glass fibers were treated with silane coupling agents at different concentrations. The initial microfracture stress and strain increased with silane concentration. At low concentrations, however, initial microfracture stress and strain did not increase. The reinforcement in warp direction was more improved than that in weft direction. The scanning electron microscopic observation of warp and weft fibers at the fracture surface showed no difference in adhesion between two tensile directions. From the observation of cross sections of the specimens, the fabric structure such as the expansion of fiber bundle or the degree of bending of the fibers, was different between warp and weft directions, which suggested that the fabric structure affected the microfracture stress and strain.

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The effects of ionic strength, temperature, and urea on the behaviors of methyl orangedodecyltrimethylammonium complex (MO-DT complex) were examined. The mean activity coefficients (γ±) of both the ions, methyl orange anion and dodecyltrimethylammonium cation in aqueous sodium chloride solution were determined by solubility measurements. Thermodynamic solubility products of MO-DT complex at 15, 25, and 35°C were 3.159×10^-10, 8.418×10^-10, and 22.889×10^-10 (mol/L)², respectively. An increse in NaCl gives rise first to reduced γ± values and then to increased γ± values. The γ± values were correlated to the ionic strength according to the equation, where A and B are the constants which involve absolute temperature and dielectric constant of the solvent. The term I is ionic strength. The symbols a′ and b′ represent the distance (Å) between the nearest ions and an adjustable parameter, respectively. z⁺ and z^- mean the charges of the cation and the anion. The γ± values obtained fit in with the equation when a′=3.5 and b′=0.2 are given. An increase in urea concentration in aqueous solution increased the solubilities of the complex.

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Lipolytic behaviors were investigated for four triglycerides (TG), namely triolein (TO), trilaurin (TL), trimyristin (TM) and tripalmitin (TP), applied on cotton fabric. By immersing them in a solution of a lipase for detergent, FUSALIUM of fungal origin, at pH 8.0 and 50°C, changes with time of the amounts of the TG's on the fabric and of the lipolytic products were pursued. It was observed that TO and TL, both having melting temperatures lower than 50°C, partially migrated into the solution and hence the lipolysis proceeded both on the fabric and in the solution. On the other hand, TM, having a melting temperature at 55°C, was lipolyzed solely on the fabric and the hydrolysate, mylistic acid (MA), having a melting temperature close to 50°C, was found to migrate into the solution from the early stage of the lipolysis. TP, having a melting temperature much higher than 50°C, gave the hydrolyzate solely on the fabric.

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Polyester fibers comprising poly (ethylene oxide) (PEO), sodium p-dodecylbenzenesulfonate (DSAS) and sodium chloride (NaCl) were prepared by melt blend spinning of poly (ethylene terephthalate) (PET) and the four component copolyesters which were prepared by condensation of PET oligomer and polyethylene glycol in the presence of DSAS and NaCl. The blend morphologies and the mechanical and antistatic properties of the blend fibers obtained were investigated. Furthermore, the mechanism for producing the antistatic property by incorporation of hydrophilic agents and the factors affecting the durability of the antistatic property were also analyzed. It was shown that in the PET/PEO/DSAS/NaCl four component system, all of the three agents are in a state of synergistic cooperation to give a better and more durable antistatic property than in the case where each of the antistatic agents was blended with PET separately.

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The effects of delignification with acidified sodium chlorite and phosphorylation with phosphoric acidurea on swelling behavior of woodmeal were investigated. Chlorite treatment of todomatsu was quite selective in removing lignin, and this treatment caused no significant change in carbohydrate content. Chlorite treatment of woodmeal followed by phosphorylation rapidly increased its water absorbency with increasing degree of delignification up to 30%. After phosphorylation, the woodmeal with 65% of degree of delignification had maximum water absorbency (141g H₂O/g absorbent). The removal of lignin was a dominant factor for the hydrogelation of phosphorylated products. The water absorbencies increased with increasing content of phosphate groups in the products, and reached a maximum at the phosphorus content of 6.6% (0.43 ester group/glucose anhydride unit). These results indicated that the water absorbency of phosphorylated products depended on the degree of substitution of phosphate groups. Sufficient hydrogelation required the phosphorylation with 60g of urea and 1.5g of phosphoric acid on 2g of chlorite-treated woodmeal at 150°C for 60min.

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Cells of Trichoderma viride, a cellulolytic fungus, were immobilized in chitosan gel beads and employed for producing cellulase by a repeating batch procedure. The activity of the immobilized cells increased with extending culture period, and reached a maximum, 37 μg of reducing sugars per mL of culture filtrate, in 6 days. This value was about 1/4 of that for free cells. The enzyme activity of chitosan gel-immobilized cells in the repeated, batch culture retained about 50% of the initial activity after ten times of batch culture.

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