The structures of polypropylene/polyamide 6 (hereafter “PP/PA6”) blend fibers with different blending ratios are investigated. Crystalline orientation is hardly observed in the undrawn PA6 and PP fibers, while it is observed even in the undrawn blend fibers at the draft ratio as low as 3.0 to 4.0. Maybe this is because the crystallization of PP phase is caused at high temperature by high chemical potential. Also maybe this is because the draft deformation of PP is substantially larger than that of PA6 due to lower viscosity of PP than PA6. Two endothermic peaks are observed in the drawn blend fibers containing 60% or less of PA6. It is considered that the peak on the lower temperature side corresponds to an imperfect or very fine crystal of PA6 and it is generated by drawing the blend fiber because the PP is easily mixed with the PA6 phase as the content of PP increases. Since the α-dispersion peaks of the dynamic mechanical properties of PA6 and PP are apart from each other, it is found that both phases are not mixed with from an order of magnitude of molecular chain.

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We prepared the blend solution of hydroxypropyl cellulose (HPC) and chitosan (CS), which has the chemical structure similar to HPC, in a co-solvent (aqueous acetic acid solution) and tried to crosslink HPC and CS with a crosslinker (Glutaraldehyde) in the presence of acid catalyst (Hydrochloric acid: HCI). The texture of the cast blend films observed with a polarized microscope depended on the cast conditions; the blend films casted in the presence of HCl exhibited the smooth surface and were insoluble in water and in an aqueous acetic acid solution. The piled network structures were observed with a scanning electron microscope. Circular dichroic (CD) spectroscopy revealed that the homogeneity of macroscopic molecular order is improved and the cholesteric pitch increases with adding HCl.
The additivity rule could not be applied to blend composition dependence of both half-value width and wavelength at CD peak. These results suggested that HPC is partially miscible with CS in macroscopic order, and HPC/CS blend would possibly result in a semi-interpenetrating polymer network. The swell ratio depended on the blend compositions and acidity of swelling agent. The blend films of higher HPC component swelled greatly in 100% acetic acid. This will be due to the higher crosslinking density of CS component than that of HPC component.

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In order to obtain the basic data for preparation of self-coloring cholesteric films based on crosslinked hydroxypropyl cellulose (HPC). we prepared the HPC liquid crystalline solution and investigated the effects of HPC concentration, temperature and addition of surfactant on the wavelength of reflective light (λ) by spectrophotometry in the concentration range of 58 to 66wt%. The value of λ decreased with HPC concentration and increased with temperature. The pitch of cholesteric helix (P) was derived from measurements of mean refractive indices and of λ. The dependence of P on the HPC concentration (C_v, in volume fraction) was investigated at 20°C; The reciprocal of P was proportional to C_v⁴²⁷ in the region below C_v=0.57, whereas that was proportional to C_v^2.35 in the region above C_v=0.57. The power index also depended on the temperature.
Regardless of the surfactant type (anionic, cationic and nonionic), the effect of surfactant on the value of λ depended on the HPC concentration and temperature.
The homogeneous blue and heterogeneous red solid films could be cast and the color of films strongly depended on the cast conditions. The self-coloring solid films should be prepared at higher temperature.

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Never-dried American cotton fibers taken from cotton bolls at different stages of growth were treated with acrylonitrile after impregnating with an aqueous sodium hydroxide solution. The water absorbency of the treated fibers was measured by the centrifugation method and the bound water content was determined by differential scanning calorimetry. These experiments showed that the high water absorbency of never-dried cotton fibers could be preserved permanently by this chemical treatment even after complete drying. It was presumed for this reason that the cyanoethyl groups introduced onto cellulose molecules in a small amount by this treatment prevented the irreversible structure formation by hydrogen bonds between cellulose molecules during the drying process.

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Acrylonitrile (AN)/Methylacrylate (MA) copolymer (AN/MA=90/10 wt%, Mw=15.9×10⁴) solutions dissolved in 58 wt% aqueous NaSCN were coagulated in a dilute aqueous NaSCN using the film coagulation method and changes of properties of gel with the time in coagulation were investigated.
In the process of coagulation, the composition of gel changed continuously. The polymer precipitated and coagulation completed when a percentage of NaSCN in gel decreased to 25-30 wt%.
Until a percentage of NaSCN in gel decreased to 25-30 wt%, a percentage of polymer in gel was constant and was almost same as that in the polymer solutions. Inter-diffusion between NaSCN and coagulant (water) occurred. The amount of NaSCN diffused out of gel and coagulant diffused into gel were equal.
When a percentage of NaSCN in gel decreased below 25 wt%, diffusion of coagulant into gel became almost zero and one-way diffusion of NaSCN and water out of gel occurred, then a percentage of polymer in gel began to increase and gel began to contract.

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What factors of woven fabrics affect the transverse slippage in the sewing process of two-ply fabrics was investigated by the discriminant analysis; the seam specimens used were classified into two or three groups on the basis of the maximum amount of slippage. The results showed that the weight and the shear rigidity parallel to sewing direction were very influential on the transverse slippage; and that the bending rigidity was also contributory to the slippage but not so crucial compared with the former two factors. The principal component analysis of the fabric data such as weight, thickness, bending rigidity and shear rigidity showed that fabrics that caused the transverse slippage could be classified on the scatter chart defined by the first two principal axes. The results obtained will be useful in selecting fabrics at the stage of planning, and in preventing the slippage at the stage of sewing.

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Optically clear films of chitin/poly(N-vinyl pyrrolidone) blends were prepared over a wide composition range from mixed polymer solutions in formic acid/dichrolomethane by solvent evaporation. Glass transition temperature (T_g) of chitin/PVP blends was observed at a temperature higher than that of PVP homopolymer by differential scanning calorimetry (DSC). T_g increased with increasing PVP content in a systematic manner. This suggested that the polymer pair forms a miscible phase in the binary blend films. FT-IR spectra indicated the presence of an intermolecular interaction between the two constituent polymers. At the same time, the chitin component was found to be partly esterified by formic acid in the dissolution process.

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