Films of ultrahigh molecular weight (3×10⁶) polyethylene were prepared by gelation/crystallization from decalin and/or ρ-xylene solutions according to the method of Smith and Lemstra. The Young's moduli of the gel films prepared from decalin solution were higher than those prepared from xylene solution. This phenomenon was studied in terms of the relationship between the reduced viscosity of the solutions and the morphology of the resultant films. The morphology was estimated by wide angle X-ray diffraction, small angle X-ray scattering, and birefringence. It turned out that the Young's modulus is affected by the crystallinity and the crystallinity is also sensitive to the size or extension in space of polyethylene chains in the solution.

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In order to obtain the solubility parameter δ for isotactic polypropylene(i-PP), the composition dependence of melting temperature for the rotational isomeric states (RIS) model of atactic polypropylene(a-PP) was investigated on the basis of modified Flory's equation on melting of copolymer, because a-PP can be treated as a binary random copolymer composed of meso and racemic units. This analysis found for i-PP that the transition enthalpy h_x per molar structural unit due to quasi-crystals in amorphous regions was 1470 cal/mol under h_u/s_u=h_x/s_x=T_m⁰ (457 K) with h_u=1900cal/mol, and 1880cal/mol under (2h_u-h_x)/(2s_u-s_x)=T_m⁰ (457K) with h_u=1900cal/mol and s_u=4.20cal/mol•deg. Where h_u is the heat of fusion per molar structural unit, s_u is the entropy of fusion per molar structural unit, and s_x is the transition entropy per molar structural unit due to quasi-crystals in amorphous regions. Substituing these values of h_x into δ=(h₀/V₀)^1/2. where h₀=h_u+h_x is the cohesive enthalpy per molar structural unit and V₀ is the molar valume, gave δ=8.26_??_8.75 (cal/cc)^1/2 for i-PP.

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Three celluloses with different degree of polymerization (DP) were esterified by the reaction with p-phenylazobenzoyl chloride and the esterification was found to proceed easier for cellulose with lower DP. Influence of DP of cellulose p-phenylazobenzoate (AB-cellulose) obtained on the formation behavior of liquid crystalline phases in the dark and under irradiation with UV light was investigated. In both solvents, chloroform and tetrahydrofuran, the critical concentration of the AB-celluloses for the formation of the ordered structure decreased markedly with the increasing DP of the AB-cellulose. The difference between the critical concentrations in the dark and under irradiation with UV light increased. Disappearing times of the liquid crystalline phase once formed at the concentration slightly higher than the critical concentranion in the dark, under irradiation with UV light were also found to decrease with the increasing DP of the AB-cellulose. These results were deduced to result from easier segmental motion of cellulose backbone of the AB-cellulose with higher DP, because of the lower critical concentration. From these results, it was concluded that the AB-celluloses with higher DP of cellulose backbone were more favorable to form and photoregulate the liquid crystalline phase.

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Cellulose dissolved in a mixture of lithium chloride and N, N-dimethylacetamide (LiCl/DMAc) was esterified with 4-perfluorononenyloxy phthalic anhydride (PFPA) using triethylamine (TEA) or pyridine as a catalyst. The products obtained with the different catalysts had the same degree of substitution (DS) of 2. 1. The fluorine-containing cellulose derivatives with DSs of 0.16 and 0.36 were also prepared by esterifications of ethyl cellulose (EC; DS of 2.5) with PFPA and with 1, 1, 2, 2, 3-pentafluoropropyloxy-2, 2-difluoropropionyl fluoride (PDAF), respectively. Formation of these derivatives was confirmed by IR, ¹H- and ¹⁹F-NMR spectroscopies. Dynamic viscoelastic and thermoplastic characteristics of cellulose and EC were changed considerably by their derivatization. Refractive indices of fluorine-containing cellulose derivatives are relatively low, 1.443-1.458. All the products reveal low hygroscopicity compared with that of the starting materials. EC, PFPA-esterified EC and PDAF-esterified EC have low dielectric constants and low dielectric loss tangents, so that they can be regarded as good insulators.

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It was found that the values of diffusion coefficient of 1, 4-diaminoanthraquinone (C. I. Dis. Violet 1) in a nylon 6 film, D_f, obtained from the concentration-distance profiles at various temperature are greater than the corresponding values obtained from the rate of desorption data by a factor of about 2. In order to clarify the reason for the disagreement in D_f, we determined the adsorption isotherms and the concentration profiles of the dye in the film from aqueous solutions at 60, 80 and 90°C. The isotherms and the profiles were analyzed with the aid of a computer. The observed isotherms were not linear but curved, convex to upward, particularly in the range or low dyebath concentration, C_S. These isotherms fitted very well to the isotherms calculated by a linear combination of a Nernst type partition and a Langmuir sorption. Therefore, the sorption and diffusion behavior of the dye were explained in terms of the dual sorption model, in which the dye exists in the substrate as the two different species, i.e., the dye adsorbed by the Langmuir sorption (adsorbed species) and that dissolved in the film by the partition mechanism (dissolved species).
The analysis of the adsorption isotherms and the profiles on the basis of this model revealed following facts. (1) The concentration of the dissolved species, C_P, is normally higher than that of the adsorbed species, C_L. However, ratio C_L/C_P increases with a decrease in the total dye concentration in the film, C_f and with decreasing temperature. (2) The actual diffusivity of the dye in the film, the diffusion coefficient of the dye as a function of C_f, D_(C) is not constant but decreases with C_f. This tendency becomes more pronounced at lower temperature. (3) The diffusion coefficient of the dissolved species, D_L_??_, is greater than that of the adsorbed species, D_P_??_, by a factor of about 2.5 at each temperature. The actual diffusivity of the dissolved species, D_P(C), decreases with C_f. While that of the adsorbed species, D_L(C), increases with decreasing C_f. The disagreement in the value of D_f mentioned above was explained in terms of the dual sorption model.

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Chitosan membranes were prepared by casting acetic acid solutions of chitosan with different degree of polymerization. One of them was further treated with a chemical crosslinker. The effective charge density on the membrane was calculated by Teorell-Meyer-Sievers theory from the membrane potential determined with potassium chloride. The charge density depended mainly on the volume fraction of chitosan molecules occupied in the swollen membrane. The permeability of the membrane was determined for four simple electrolytes. All membranes showed the concentration dependence of salt on the permeability through the Donnan effect in the same way as reported in the previous paper¹⁾. At the same time, the permeability was. negatively dependent on the radii of hydrated ions at high concentrations where the Donnan effect disappeared. The membrane prepared from the chitosan with the low degree of polymerization (low DP chitosan) indicated the rough membrane structure, the high permeability and the low charge density compared with the membrane prepared from the chitosan with the high degree of polymerization (high DP chitosan). It suggested that the former membrane had the large swellability resulting from a fewer entanglements of molecules owing to the remarkably shorter average molecular chain length. An introduction of chemical crosslinks gave rise to slight decreases in the charge density as well as the degree of hydration of the membrane and the partition coefficient of salts, suggesting the influence of decrease of free amino groups caused by the formation of Sciff's base between amino groups of chitosan and aldehyde groups of crosslinking compound. In addition, the rigid pores effective for the diffusion of the small salts might be formed by crosslinking.

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Refined silk fibroin obtained from waste cocoons was dissolved in a mixture of ethanol and neutral salt (calcium chloride) solution and the solution thus obtained was centrifuged and then acidified with an organic acid after dialysis. The pH of the resulting solution was in the acid side of the isoelectric point (pl=3.8-3.9). Fibroin gelation was carried out in an air-conditioned room. The gel strength and gelling rate were investigated under different conditions such as pH and concentration of fibroin solution. Structural features were studied by electron microscopy and infrared spectroscopy.

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The specific Young's modulus, E_s/(ρ_s/ρ_f), was introduced to experimentally evaluate the effectiveness of the stress transfer factor of interfiber bonding in handmade pulpsheet. As a result of the application of this modulus to calendered sheet, no additional interfiber bonding was proved to be formed, although the Young's modulus calculated by the conventional method increased with decreasing thickness. Dimension of the specific Young's modulus, Pa, provides a logical approach in mechanical discussion of paper. A further investigation is needed to study the quantitative treatment of the elastic properties of paper.

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The effect of protease on detergency of surfactant (AOT)/isooctane/water system was studied. For evaluating the detergency of the system, the artificially blood-soiled fabric, EMPA-111, was used. The enzyme exhibited pronounced activity in the system. The enzyme would be solubilized in the core of reverse micelle formed. The solubilized water, which may be in the reverse micelle in the system, was essential for the enzyme action. In the system with low water content, w=[H₂O]/[AOT]<20, the effect of enzyme was less remarkable. The effect of enzyme was distinguishing in the system at low surfactant concentration. In the system the enzyme considerably enhanced the detergency, while the system without enzyme did not show significant detergency. With increasing the surfactant concentration in the system, the detergency of the system with or even without enzyme increased. The contribution of enzyme, therefore, became less remarkable at high surfactant concentrations.

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