An uncatalyzed reaction of formaldehyde with cotton cellulose at 125°C is described, and the fabric properties of the product are characterized. It is shown that this formaldehyde-modified fabric had a more homogeneous distribution of cross linkages in the fiber structure than the product from a boric acid-catalyzed reaction conducted under similar conditions. The more homogeneous distribution of cross linkages is particularly favorable for the development of high wrinkle recovery angles.

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Cotton celluloses selected for pronounced differences in crystallinities and accessibilities have been cross-linked by the vapor-phase deposition of formaldehyde under conditions previously shown to cause different degrees of molecular degradation. The products at various levels of bound formaldehyde have been analyzed for sol and gel fractions and for degree of distention of the gel fraction in cupriethylenediamine hydroxide. The results of these analyses provide quantitative information on the gross uniformity of distribution of cross linkages in the fiber structure of the celluloses, the uniformity of the distribution of cross linkages along the molecular chains of the cellulose, and the ratio of chain scission to molecular cross-linking in the cross-linked compositions. These analyses can now be applied with greater confidence to obtain useful information on cross-linked celluloses, despite the heterogeneity of phases in the cross-linking reactions and the crystallinity of the cellulose.

High speed impact testing is important and necessary, because materials tested at static speed show quite different behaviour in case of high speeds. The impact machine used in this study is a rotary disk type impact tensile testing machine. The diameter of the disk is 1800mm and the thickness is 100mm. The disk is a Ni-Mo-V steel forging, which weighs 2300kg and rotates up to 1450rpm.The speed of the disk reaches 140m/sec when it rotates at 1450rpm, and the sample of the fiber or high polymer is pulled by the jaw at the same speed. The tensile load is measured and detected by strain gauge fixed on the sample holder and the output of the strain gauge is led to the vertical axis of the synchroscope. The horizontal axis of this synchroscope is time axis and is drawn by a single sweeper driven by an outside circuit containing 45 volt.Various plasticizers such as n-dioctyl phthalate, dioctyl adipate, tricresyl phosphate were added to study their effect on the impact behaviour of polyvinyl chloride sheet. The rolling of the mixture a load of 150kg/cm2. The sheet was punched in to the shape of dumbell and used as sample.The effect of degree of polymerization and added amount of vinyl acetate was also studied.The breaking stress of polyvinyl chloride decreases with the increase of the amount of plasticizer and the effect of strain rate is not clear in this case. The breaking stress increases a little while the degree of polymerization rises and decreases when the added amount of vinyl acetate increases. tests. The result shows that the sample containing less and no amount of plasticizer do not extend at different speeds but the sample containing more amount of plasticizer extend more at static speed and less at high speed. This shows easiness of plastic flow at high speed. At a certain speed the value of extension drops sharply and this speed shifts toward higher value when the amount of plasticizer increases. The decrease of cross-sectional area is less in case of high speed. The critical velocity measured from the stress-strain curve drawn at impact speed shows that it increases with the addition of plasticizer and its value was compared with that of textile fiber. The propagation of plastic wave was also determined.

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