Graft copolymerization of ethyl acrylate for wool fibers in aqueous K₂S₂O₈-butylcarbitol (BC) system at O°C. was found to proceed via a specific (or unique) mechanism. As the concentration of BC was increased, the graft-on and grafting efficiency became lower. Homopolymer was not formed in the absence of BC, and it was more easy to obtain highly grafted fibers (e. g. 3000 times of the original weight). Apparent molecular weight between crosslink points, Mc was obtained from the experiments of swelling equilibrium. Huggins' constant k′ of the homopolymer was determined from the viscosity measurement. It was concluded that the network structure of graft polymer was more easily formed with the lower concentration of BC by the mechanism of popcorn polymerization.

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Graft copolymerization of methyl methacrylate onto wool fibers in aqueous LiBr-K₂S₂O₈ redox system was investigated. Homopolymer was not formed in this system. Effects of concentrations of butylcarbitol (BC) and K₂S₂O₈ on the rate of grafting, the average molecular weight of graft polymer and the concentration of monomer in wool fibers, [M]_fib was studied. [M]_fib increases with increasing extent of grafting while the effective concentration of monomer [M]_eff decreases with increasing extent of grafting. The main location of polymer deposition was found to be controlled by reaction conditions.
(1) In the case of low concentration of BC and high concentration of K₂S₂O₈, the rates of grafting and formation of grafting sites are low, and the polymer is deposited unevenly in the radial direction of the fiber section.
(2) In the case of low concentrations of BC and K₂S₂O₈, the rate of grafting is high while the rate of formation of grafting sites is low, and the polymer is deposited mainly in orthocortex.
(3) In the case of high concentration of BC and low concentration of K₂S₂O₈, the rates of grafting and formation of grafting sites are high, and relatively homogeneous distribution of the polymer was observed across the fiber section.

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The location of hydroxyl groups on (101) planes of cellulose and cellulose xanthate crystals has been investigated in relation to the orientation mechanism of selective uniplanar orientation of (101) planes, anisotropic swelling procedures and crystal structure of cellulose xanthates in the earlier paper of this series. The object of this paper is to describe the conversion mechanism of cellulose xanthate into cellulose IV on regeneration. It has been found that insoluble metal xanthates are converted into cellulose IV on decomposion in hot water (60°C), while sodium cellulose xanthate into cellulose II. This phenomena might be explained as follows:
It seems reasonable to assume that metal cross-bonds are formed mostly between (101) planes of cellulose xanthate paracrystals, considering the fact that hydroxyl groups and xanthate groups located on (101) planes as mentioned in the previous paper of this series. Consequently the molecules should be tightly attracted to each other and closely packed in the direction perpendicular to (101) planes. On the other hand, lattice spacing of (101) planes of cellulose IV is smaller by 33% than that of cellulose II. If these cellulose xanthates are decomposed rapidly, the molecules will probably be forced to approach nearer in the direction perpendicular to (101) planes. This provides the molecules to recrystallize so as to have the smaller distance of (101) planes, that is, cellulose IV is formed. On the contrary, cellulose II are formed if the cellulose xanthates are decomposed gradually by mild regeneration. Thus the zinc cellulose xanthate is converted effectively into cellulose IV by heating it in dilute sulphuric acid at temperature higher than 60°C within a few minutes. One might conclued that cellulose IV is formed directly from metal cellulose xanthate and not through cellulose II, since cellulose II is never converted into cellose IV under such a condition as above described. The conversion into cellulose IV in the above case mainly depends on the density of cross-bonds between the molecules. This can be demonstrated by the fact that the conversion increases up to 90% with increasing γ-value of cellulose xanthate. It was found that conversion into cellulose IV was promoted by the action of lateral compression when decomposition of cellulose xanthate was carried out under tension. This effect can not be observed when cellulose II is converted into cellulose IV by heat treatment above 200°C in glycerin, indicating that the mechanism in this case would be essentially different from that of ours.

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The interactions of polyacrylic acid (PAA), polymethacrylic acid (PMA), polyacrylamide (PAAm) and polymethacrylamide (PMAm) with some disperse dyes such as azobenzene, p-hydroxyazobenzene and p-aminoazobenzene were studied by an equilibrium dialysis method at 5°, 15° and 25°C.
It was found that PMA displays a strong binding affinity toward these disperse dyes and on the contrary PMAm does a weak one. In the cases of PAA and PAAm no similar phenomena were observed. An addition of urea to PMA solution promoted a marked decrease in the binding ability.
The results are interpreted in terms of the interaction of these dyes with partially hydrophobic tightly coiled chains of PMA, which are stable in aqueous solution and not in aqueous urea solution.
The binding isotherm between the dyes and PMA was exhibited by the Langmuir one, so the thermodynamic parameters, free energy change, enthalpy change and unitary entropy change, can be calculated from the Klotz's equation. The free energy change and the enthalpy change obtained in this work are all negative and the unitary entropy change is large positive. The favorable binding process, therefore, involves two main contributions, an entropy gain and an exothermic interaction. Comparing the effect of the entropy term with that of the enthalpy one, the former is larger than the latter in the course of the binding process. In particular azobenzene which is the least polar compound has larger positive entropy change.
From the above data it was deduced that the large positive unitary entropy change may be attributed to the hydrophobic interaction between the dyes and PMA.
The viscosity of PMA, PAA, PAAm and PMAm in aqueous solution and aqueous urea solution was measured and discussed in some detal.

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A micro-hardness tester based on the static indentation method was designed to study the hardness of polymer films. The contact area of a film with an indenter under loading was measurable in the terter. This tester has the following characteristics:
1) The error caused by elastic recovery characteristic of visco-elastic materials can be decreased.
2) The testing load changes continuously from 1g to 300g.
3) The testing temperature can be changes widely.
The results obtained by application of the tester are as follows;
i) The Vickers and Brinell hardness of thin polymer films was measured with an indenter under a proper small load. The hardness was independent upon the thickness of samples used in this experiment. A difference between the hardness under loaded and unloaded states for thin polymer films was observed. The hardness under unloaded state agreed with the value obtained by a commercial tester.
ii) In the case of uniaxially drawn PET, the shape of the contact area of the film with a ball indenter was ellipse, whose minor axis coincids with the drawing direction. The ratio of the major axis to the minor was proportional to the birefringence of the samples.

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Transverse markings are observed when some of the semi-crystalline polymers are extended close to their breaking point. The origin of these transverse markings have not been elucidated exactly to the date. The local regions with naticiable transverse markings appear in the redrawn polyethylene and polypropylene films. Ripple-like creases may be generated at the contour where two localised regions with different extension ratio's come in contact with each other.
Molecular chains in these two regions do not fit well on this boundary without causing large strain on one of the regions. Transverse markings appear in this strained regions.

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