It was reported in our previous papers that reactions of wool fibers with various reducing sugars,such as xylose, glucose, and maltose, gave their fibers yellowish or brownish coloration. These coloration reactions are well known as Maillard reaction in the food chemistry. However, it was also clarified there that the colored wool fibers showed the worst color fastness results to light, similar to fibers dyed by natural dyestuffs. In this paper, the wool fibers colored by the Maillard reaction were also mordanted by the same techniques of natural dyestuffs using the following three cationic ions; Al³⁺, Cu²⁺, and Fe²⁺, where the effects of these mordant processing both to their color fastness results and to their color changes were investigated in detail. As a result, the wool fibers mordanted by CuSO₄ afforded their excellent color fastness to light (grade 4 at the blue scale of JIS L 0843 (color fastness to Xe arc lamp light)), and the color of these fibers became darker than one of the fibers colored only by the Maillard reaction.

2,2,6,6-Tetramethylpiperidine-1-oxyl radical (TEMPO) and their derivatives, 4-acetamide-TEMPO and 4-hydroxy-TEMPO, were dissolved in water, and their degradation behavior by Fenton reaction was studied under various conditions, considering the treatment of the N-oxyl radical-containing washing effluents formed during TEMPO-mediated oxidation of various celluloses. The N-oxyl radicals were treated with FeSO₄ and H₂O₂ in water at pH 2.7 and 35 ̊C for various times, and time-dependent concentrations of the N-oxyl radicals were determined by electron spin resonance. When 0.29 mmol FeSO₄ and 0.34 mmol H₂O₂ were used to the 100 mL solution containing 0.01 g N-oxyl radical (i.e., ~100 ppm), its concentration became below the detection limit (< 0.01 ppm) after Fenton reaction for 90 min. When 5% (v/v) ethanol, dimethylsulfoxide or acetone was present in the TEMPO-containing solution, similar degradation behavior by Fenton reaction was observed. The degradation products of TEMPO present in the supernatant and solid fractions formed during Fenton reaction were analyzed by gas-chromatography-mass spectroscopy, solid- and liquid-state ¹³C-NMR, ion chromatography and others. The results indicate that the N-oxyl radical compounds were mostly degraded to CO₂, water and nitrate/nitrite ions by Fenton reaction. Thus, Fenton reaction is available for the treatment of washing effluents formed during TEMPO-mediated oxidation of celluloses.

High-speed melt spinning of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) with the 3- hydroxyhexanoate composition of 5.4 mol% was carried out. Melt processing of PHBH is known to be difficult because of the combination of its low glass transition temperature being lower than the ambient temperature and low crystallization rate. With the aim of overcoming such difficulty, the high-speed melt spinning process was applied to utilize the effect of tensile stress on the acceleration of crystallization rate. Melt spinning experiment in this study revealed that the crystallization of PHBH proceeded in the spin-line at high take-up velocities even when the extrusion temperature was higher than the T_m of pure PHB where the nucleus of PHB crystals are reported to disappear. WAXD analysis of as-spun fibers showed that the crystalline orientation of α-form crystals increased with an increase in the take-up velocity. A small amount of β-form crystals started to appear at high take-up velocities. This was another evidence for the occurrence of crystallization under high tensile stress. Results of WAXD and birefringence measurements also suggested that the fiber structure development was promoted if the extrusion condition of higher throughput rate was adopted. This was due to the suppressed thermal decomposition originated from the shorter residence time of polymer in the extrusion system. Mechanical properties of as-spun fibers increased with an increase in the take-up velocity. The highest tensile strength and tensile modulus of 156 MPa and 2.43 GPa were obtained under the conditions of take-up velocity 6 km/min, extrusion temperature 180 ̊C and total through-put rate for four filaments 10 g/min.