In order to improve the wrinkle recovery of wool fabrics, various methods have been proposed, for example, incorporation of some bulky molecules, crosslinking with appropriate bifunctional compounds, and treatment with mercury(II) acetate and so on. In this paper, a new attempt for improving the wrinkle recovery of wool fabrics has been proposed, that is an introduction of much thiol(-SH) groups in the fabrics, considering the theory of wrinkle formation. The analysis of physical properties of the much -SH groups introduced wool fabrics, reveals that the wrinkle recovery and set property have been improved without any changes in weight, in color and handling. The sulfur content in the treated wool was found to be increased by analysing with X-ray fluorometry. This fact leads us to an conclusion that the wrinkle recovery mechanism of the present method might be based on the formation of disulfide(-SS-) groups in wool fabrics. As a comparison, we examined the wrinkle recovery mechanism by mercury(II) acetate treatment, and found that Hg ions could present as -S-Hg⁺ in the fabrics, which might eliminate the hydrogen bond.

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The influence of supermolecular structures on the axial compressional behavior of PVA fibers was studied. Two kinds of PVA fibers with different supermolecular structures, HOMO-PVA fibers and BAND-PVA fibers, were used in this study. HOMO-PVA fibers with a long-period structure which is made up of stacked folded-chain crystals have a homogeneous appearance, while BAND-PVA fibers with extended-chain crystals have a characteristic banded structure. Axial deformation behavior of the BAND-PVA fibers was quite different from that of HOMO-PVA fibers. When the BAND-PVA fibers are axially compressed, PVA molecules in the banded structure are considerably kinked in zigzag fashion from band to band to form deep “creases”. On the other hand, when the HOMO-PVA fibers are axially compressed, kink bands are formed at angles of ∼45° to the fiber axis here and there along the fiber axis or a series of continuous bands with 1μm spacing are formed at angles of ∼75° over the whole fiber. It is suggested that (101) [010] slip plays an important role in the deformation of the BAND-PVA fibers.

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Optimum conditions for graft copolymerization of poly(methacrylamide) on silk fabrics have been observed at a narrow range of pH between 1.2 and 2.8. With grafting of poly(methacrylamide) on silk fibers, shrinkages of cloths were observed and the thickness and the yarn densities of cloths increased. In the low pH regions for the graft copolymerization, tensile strength was maintained and elongation of fiber at break increased, although the fibers used have been damaged. It was considered to be due to the effect of the mutual entanglement of poly(methacrylamide) grafted on fibroin. Bending rigidity of fabrics increased, but abrasion resistance was improved by grafting. Crease resistance decreased by 20% with 60% grafting, and a somewhat increase of crease resistance in water have been observed.

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For the complex films composed of various molar (repeat unit) ratios of chitosan and carboxymethyl chitin (CM chitin) moisture sorptions were measured at 20°C, 65%RH and 20°C, 90%RH and water sorptions were measured in 5, 000-fold as much water as complex film after 24h at 30°C. Hygroscopicities of complex films became higher as the increase of the content of CM chitin irrespective of relative humidity and they did higher independent of the composition of complex film at 90%RH compared with those at 65%RH. Water sorptions of complex films were lower as molar (repeat unit) ratios of chitosan and CM chitin were in the range of 0.4/0.6 to 0.3/0.7. Except this range water sorptions of complex films were higher. The lowest value in water sorption was seen in approximately 1.0 of -NH₂/-COOH ratio, because it is then easy for chitosan and CM chitin to form polyion complex.

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Two-component random copolypeptide P(HPG-ran-LA) fibers consisting of N-hydroxypropyl-L-glutamine and L-alanine with different copolymer composition were prepared by an aminolysis reaction of poly(γ-methyl-L-glutamate/L-alanine) fibers with 3-amino-1-propanol, followed by crosslinking reaction with 1, 8-octamethylene diamine. The in vitro hydrolysis was carried out using ficin, one of proteases. The tensile properties and the in vitro hydrolysis of these hydrophilic fibers were highly dependent on the degree of swelling in phosphate buffer solution. The study of the weight loss of the fibers upon the enzymatic hydrolysis suggested that the degradation of the fibers occurred gradually from their surface into their core. Scanning electron microscopy also supported the surface hydrolysis. The weight loss of the fibers in the course of hydrolysis took place almost in parallel with the strength loss of the fibers.

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Melting behaviour of ethylene-propylene random copolymer (EP random copolymer)/toluene thermoreversible gels was measured by the falling ball method (FBM) and differential scanning calorimetry (DSC). By applying the theory proposed by Takahashi, Nakamura and Kagawa (Takahashi theory) to the gel melting temperature T^g_m measured by FBM, values of number of monomers ξ per chain in a junction point were evaluated. Further, values of ζ and s were evaluated by the Tanaka theory. ζ in Tanaka theory has the same physical meaning as ξ in Takahashi theory and s means the number of polymer chains contained in a junction point. The obtained values of ζ have the same order of magnitude but smaller than ξ. In DSC measurements, the enthalpy of melting (ΔH_m) of junction points was measured. ΔH_m increases with the increase of gelation time, and then approaches a constant value. The gelation time t_h, which is necessary to reach the equilibrium value of ΔH_m, is extremely longer than the gelation time t_m, which is necessary to obtain a constant value of T^g_m.

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The fungus Cunninghamella polymorpha, isolated from soil, efficiently degraded the anionic surfactant, sodium 2-naphthalene sulfonate formaldehyde condensates. The greatest degradation of the surfactant occurred for 48h. The initial degradation rate was 2.71mg/(lh g-dry cell debris). C. polymorpha degraded 86 and 92% of a 0.6g/l concentration of the surfactant, Demol N, in 48 and 96h, respectively.

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