Effects of the temperature dependence of photo-elastcity for the cold-drawn polyethylene terephthalate (P. E. T.) fiber and its thermal conditions at various temperatures and media were measured over a wide range of temperature under a constant heating and cooling rates after giving various extensions. Also the temperature dependence of the hot shrinkage and static tension under the same condition were investigated. The variation of the orientation of molecular chains in P. E. T. fiber at the heating and cooling process is discussed. The results obtained are as follows: 1) The temperature dependence of the retardation for untreated cold-drawn P. E. T. fiber at a low extension is that _??_ expresses maximum value in the vicinity of the transition temperature, and then decreases with the rise of temperature, while again it increases at about 120°C and monoto-nously beyond it. On the other hand, the value of _??_ at a high extention decreases up to 120°C and becomes nearly a costant value beyond it. The same behavior may be seen in relation to temperature dependence on static tension and shrikage. This may be due to progressively increased freedom of rotation of p-phenylen groups on the main chain of P. E. T. at about 120°C. 2) The variation of _??_ in _??_-T curves of the cold-drawn P. E. T. fiber which was heated in various media of heating at 80°C is smaller as the heat capacity of media becomes larger. Especially, _??_-T behavior from the glass transition temperature to 120°C reflects the effect of the cold-crystallization between the two points of transformation temperatures on the logarithmic thermal shrinkage curves. 3) The variation of _??_ in _??_-T curves of the cold-drawn and heated P, E. T. fiber decreases with the rise of temperature of heat-setting, and the higher temperature of heat-setting, the smaller rate of decreaseing of _??_ at a high extension after passing over a range of temperature on cold crystallization.
Effects of temperature by heating, heating media and draw ratio on the contribution of crystalline and non-crystalline birefringence in drawn and heated, at a constant length, polyethylene terephthalate (P. E. T.) filaments were investigated by X-ray and optical polarized microscope. Results obtained are shown as follows: 1) Both density and crystallinity (X-ray) Xx increase with rising temperature, and their values by wet-heat-set are larger than by dry-heat-set under same heated temperature. Relation between Xx (X-ray) and specific volume V calculated from density values may be a linear, independent of draw ratio and heating conditions. Xx=-8.01V+6.00 2) Relation between Xx (X-ray) and crystallinity Xd deduced from density may be a linear. Effects of draw ratio on the slope of line is small by dry-heat-set, but its slope in lower stretched filaments becomes as much as double higher stretched filaments. 3) Both optical birefringence Δn and degree of crystalline orientation π increase with rising temperature. And crystalline orientation factor fx increases with rising temperature, while it may approach to a saturated value at elevated temperature by wet-heat-set. 4) Total-birefringence is divided from the contribution of crystalline and non-crystalline birefringences. The contribution of crystalline birefringence Δnc•Xx increases with rising temperature independent of heating condition in drawn filaments. On the other hand the contribution of amorphous birefringence Δna (1-Xx) decreases in higher stretched filaments on dry-heat-set, while it varies little in low stretched. 5) The crystalline birefringence Δnc is always larger than the amorphous birefringence Δna. For higher stretched filaments, both Δnc and Δna do not vary much by dry-heat-set, while for lower stretched ones, Δnc, varies a little and Δna increases rapidly with rising temperature. 6) Relation between over-all birefringence and amorphous birefringence is a linear in both drawn filaments. And_??_ relative intensity value I(100)/I(110), and total-birefringence are linealy related to each other.
By spinning and stretching Ziegler process low pressure polyethylene, monofilaments were made and various properties have been determined. The results are as follows: 1) Relationships between tensile properties and stretch ratio have become clear. Young's modulus are 400-800kg/mm2. Maximum loop strength reachs to 14g/d and this value corresponds to the two folds of loop strength of commercial Nylon monofilament. 2) By heat set treatment under tension about 20% of Young's modulus decreases, but thermal shrinkage is much improved. 3) Tensile properties have been determined over the range 0.25-500%/min of extension speed. The dependence on extension speed are higher in polyethylene monofilament than in Nylon and polypropylene. 4) In ductile failure tests of monofilaments made by various stretch ratios, the relations between relative load and log (time to failure) are represented as one straight line. And this line is determined by molecular weight and molecular construction of raw material of each filament. The more molecular weight and side chains there are, the higher the creep resistance. Otherwise, in absolute load tests, the creep resistance of filaments having higher tenacity are higher in case of the same resin. 5) The relative load-creep resistance in twin, rope and cord are much higher by construction effect than in monofilament.
The cord fatigue in running tires is brought about mainly by heat, cyclic elongation and compression. These individual effects have been reported in previous papers. Here, reciprocal actions of heat, cyclic elongation and compression on tire cord are studied in order to make clear the fatigue mechanism of tire cord in real tires. The results obtained are as follows: (1) The changes of fine structure in tire cord caused by compression are accelarated by reciprocal actions of elongation and compression, while the changes caused by elongation are not. This phenomena are explained by the increase of compression stresses corresponding to the amount of plastic flow caused by elongation. Hence, inter-planar slip in crystallite in tire cord is promoted and filament strength decreased earlier to break down the cord when tire cord is fatigued by cyclic elongation and compression. (2) Thermal effects are enhanced on the fatigue phenomena of tire cord caused by cyclic elongation and compression, such as break-down or flow of molecular chain in amorphous region and inter-planar slip in crystallite, in addition to thermal degradation.
Bast fibers of Ganpi plant (Wickstroemia sikokiana.) were cooked with ammonium oxalate, sodium bicarbonate, sodium carbonate and sodium hydroxide to yield the four kinds of pulp. The bleaching and beating properties of each pulp and the physical properties of the paper made with it were tested. Using ammonium oxalate as cooking reagent, an excellent pulp is produced with a good yield amounting to 83.7%. The pulp prepared by the cooking with ammonium oxalate shows good beating properties and strong paper may be produced, but the lignin content of the pulp is somewhat higher. Sodium hydroxide is found to have the most effective properties to delignify and to remove hemicelluloses, but the yield of the pulp is low. The chemical components of hemicelluloses extracted from each kind of pulp was studied by paper partition chromatography. The characteristic properties of the hemicelluloses of the Ganpi bast fibers is found in the chemical structure constituted from D-xylose, 4-O-methyl-D-glucuronic acid and D-galacturonic acid. It is found that hemicelluloses resist appreciably the neutral and alkaline cookings and remain in the pulp and paper. The paper making properties of the hemicelluloses is discussed.
The influence of the chemical constitution and H. L. B. value of non-ionic surfactants upon the diffusion distribution of a direct dye in the cellulosic material was studied and carried out by means of the cellophanefilm roll method. Purified Direct Fast Red F (C. I. Direct Red 1) was used throughout the entire experiment. Eighteen non-ionic surfactants, which are classified as P. E. G.-Octylether type (I), P. E. G.-Nony-lphenylether type (II), P. E. G.-Oleylether type (III), P. E. G.-Oleylester type (IV), and P. E. G.-alkyl (C16-18) amine type (V), were employed. Each of these types contains various number of moles of ethylene glycol. From the data obtained the retarding action of these surfactants in direct dyeing is discussed below: 1) (I) shows a little retarding effect irrespective of the value of H. L. B.; i.e. the surface dye concentration Co is not appreciably altered or decrease. 2) (II), (III) and (IV) show increasing retarding effects with increased H. L. B. values. 3) (V) shows considerable retarding effects even at small H. L. B. value. The general structure of a non-ionic surfactant may be considered as composed of the three constituent groups, namely: (1) the hydrophobic group, (2) the hydrophilic group, and (3) the bridge. To show adequate retarding effects, the non-ionic surfactants should have a suitable hydrophobic group (as nonylphenol-or oleyl-group), and a suitable hydrophilic group (as 15-25 moles of ethylene glycol linkage), and the bridge of these two groups must be either of ether or ester type.