Laminar flow of polymer melts in a fishtail die is analyzed and an equation of pressure along the slit is derived for those melts which obey the “power law”. The equation yields the following index of uniformity (U), which is the ratio of the rate of extrusion at the end to that at the center of slit, _??_
where α=h/H, b=r_o/t, c=R/t, h is the lip land depth, H the lead up depth, r_o the length of the lead up section at the entrance, R the length of the lead up section at the center of the lip, t the lip land length, θ the half-angle of the lead up section, n the exponent of the power law.
The relation among α, b, c, and n for U=1.0 is also discussed.

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Pressure distribution in a coat-hanger die for laminar flow of polymer melts which obey the “power law”, is given by the solution of the following simultaneous differential equations.
where_??_
z is the distance from the end of the lip, R the channel radius, t the length of the lead up section, T the lip land length, P the pressure in the channel, p_o the atm. pressure, H the lead up depth, h the lip land depth.
The relation among the dimensions for U=1.0 is also discussed.

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Infrared absorption spectra of polyamino acids such as poly methyl-, ethyl-and benzyl-glutamate, sodium polyglutamate, poly-alanine, polyserine and poly β-alanine were measured. In all cases the intense absorption bands in the region of 700-600 cm^-1 were observed. These bands were assigned to be the Amide V bands due to N-H out-of-plane deformation mode. There are significant differences in frequency among the a-Helix (620-610 cm^-1), β-structure (700-690cm^-1) and random coil (-650 cm^-1). So-called “Amide V” band will be useful to investigate the molecular conformation of these polypeptides.

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Many kinds of copolymers of methyl-L- with D-glutamates were prepared. The residue ratio L/(D+L) was from 50 to 100%. Infrared absorption spectra of these solid films and optical rotatory dispersion of these solutions were measured. The total Helix content was estimated from the intensities of the Amide V bands. The differences in Helix content were determined from the b₀ value in Moffitt plot of optical rotatory dispersion. The amounts of Helix content can be calculated. These methods would be useful for the investigation of polypeptide helical structure.

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An attempt was made for investigating the behavior of the ladder model which was modified so as to take into account the structural peculiarities by AC network calculator- a kind of analog computor.
The response of the model can be determined over a wide range of time scale by varying values of constants in the model elements.
Steady state and transient state analysis were carried out on Blizard's model (R. B. Blizard: J. Appl. Phys., 23, 730 (1951)) corresponding to dynamic and static behaviors in mechanical systems.

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A modification of the ladder model to account for limitting values of modulus at high frequencies is proposed. The rigid wall to which one ends of dash pots are attached in Blizard's model (R. B. Blizard: J. Appl. Phys., 23, 730 (1951)) is replaced by an elastic wall which exhibit the same order of elasticity as that of the glassy state polymer. A direct correspondence between the model and the real chain molecule is conserved.

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Effect of the distribution of resistance elements and the chain ends are investigated by the method and the model which were described in part 1 and part 2. The distribution of resistance values is found to have a marked influence on the shape of retardation spectrum. Constants of terminal elements exhibit a pronounced effect on the shape of the tan δ curve. It is ooserved that the behavior of the model becomes close to that of a real polymer, when larger values are assigned to constants of terminal elements.

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In the present paper, it has been pointed out that a crystal modification of nylon 6 like the γ-form, which has recently pointed out in the iodinetreated specimen, appears to be formed by coagulation of the polymer from its solution.
In the X-ray diagram of the specimen prepared from the polymer solution of aqueous formic acid on a glass plate by evaporation of the solvent, it has been observed that a quite new diffraction with spacing of 4.65Å which can not be interpreted in terms of the old model hitherto presented by Bunn and others as well as the mesomorphic structure with the smectichexagonal chain arrangement as proposed by Kast.
From analysis of the X-ray diffraction patterns perpendicular and parallel to the film surface, it is shown that the unit cell is monoclinic with the dimensions of a=9.35Å b=16.60Å, c=4.81 Å and β=120°Cand this crystallization proceed in a selective uniplanar orientation in such a way that the specified plane (101) is parallel to the film surface. The space group of C⁵_2h-P2₁/α may be adopted for it by considering the extinction law in the electron diffraction pattern of the nylon 6 single crystal taken in this laboratory. Using these informations together with the measurements of the principal refractive indices, it is deduced that the hydrogen bonded sheets formed by the parallel chains are piled up along the direction of the α^*-axis in the reciprocal lattice, but the chain direction in each of them is reversed alternatively.

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To know the relationship between substituents of styrene derivatives and their reactivity in propagation and termination reactions, the elementary reactions in the radical polymerization of p-substituted styrenes were analyzed. In measuring radical life times we used the most proper rotating sector method.
Initiation reaction rate was determined by inhibitor method and in this paper DPPH and benzoquinone were chosen as inhibitor. Obtained k_p values of styrene, p-methylstyrene and p-methoxystyrene were 106, 84 and 71, and 2k_t values were 10.8×10⁷, 6.6×10⁷ and 3.3×10⁷l/mol·sec, respectively.

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The polymerization of p-chlorostyrene and p-cyanostyrene was studied kinetically. As poly-p-cyanostyrene was insoluble in its monomer, the polymerization was carried out in dimethylacetoamide solution. Experimental method was same as the case of styrene. Benzoquinone hardly inhibited the polymerization of these monomers and that only DPPH was used as inhibitor. Observed values of k_p of p-chlorostyrene and p-cyanostyrene were 150, 219 and 2k_t7.7×10⁷ 3.5×10⁷ at 30°C, respectively.

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Morpholine is a fairly stable solvent for polyvinyl chloride (PVC) at 50-80°C, but above 100°C combination of morpholine ring into PVC molecules occured. Thus modified PVC containing about 5% nitrogen was obtained by heating PVC with morpholine at 130°C for 3 hrs. The coloration, (yellow-orange) due to a conjugated polyene structure, and degradation of PVC was found in any condition.

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A conjugated polyene structure in the PVC modified with morpholine was disappeared by treating with azo-bis-isobutyronitrile in morpholine at about 100°C.
Thus, the decoloration of the discolored modified PVC was performed. The conditions for decoloration using azo-bis-isobutyronitrile were studied.

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The mechanical properties of Ziegler process polyethylene, heated in air oven at 100°C, were studied, and the tensile elongation of unstabilized sheets were found to be remarkably decreased. It was obvious that this thermal brittleness was owing to the changes in molecular weight and common antioxidants prevented from chain degradation. When the sheets containing the common anti-oxidants were subjected to a tensile stress of 20 kg/cm² at 100°C, the sheets became brittle in a short time and were broken, but, in this case, the change in molecular weight could not be found. Some stabilizers were found to be effective for thermal stress degradation.

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The effect of stabilizers and plasticizers on the photodegradation of polyvinylchloride (PVC) were investigated by the measurements of gel content, degree of polymerization and molecular weight distribution of the soluble PVC extracted from light exposed specimen. The color change and gel formation of PVC induced by light was observed only in the thin surface layer of each sample and the stability of PVC to light was pronouncedly improved by the addition of light stabilizers. It was shown from the outdoor exposure test, that DOP also acted to enhance the light resistance of PVC, but this effect could not be found from the weathermeter exposure test. The occurence of chain scission and crosslinking of PVC was rather slight at the surface of sample and there was no appreciable change between the molecular weight distibution of PVC exposured during a long time and that of orginal PVC.

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In the copolymerization of propylene and isoprene by TiCl₄-Al (C₂H₅) ₃ catalyst, it was found that the copolymer composition changes remarkably by the preparation condition of the catalyst. With the catalyst prepared in the presence of propylene ((P) catalyst), copolymer produced contains more propylene units than the one produced using the catalyst prepared in the presence of both monomers.
In the copolymerization reaction with (P) catalyst, the propylene content of the copolymer increased as Al/Ti mole ratio and contacting time of propylene with the catalyst forming reaction mixture increased. The copolymer composition changes with reaction time in the copolymerization. Small amount of propylene, about several times mole of TiCl₄, is sufficient to prepare the (P) catalyst.
From these results, it is concluded that the copolymerization activity of the catalyst differs with the kind of the olefin present during the catalyst forming, that the catalyst forming reaction does not finish instantaneously when the two components of the catalyst are mixed together and that the catalyst activity changes with the duration of polymerization.

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The effects of γ-rays on aqueous solutions of polyvinyl alcohol (PVA) in presence of oxygen were studied. Random degradation of PVA is observed under oxygen atomosphere, but when oxygen dissolved in solution is not so much, crosslinking occurs. The oxygen plays a very important role for radiation effect on the aqueous polyvinyl alcohol solution.
G-values for main chain scission were found to be 0.2-0.6, which became larger at higher dose rate and higher concentration. When H₂O₂ was added at the concentration of 10^-2 mol/l, G_d-values became 4 times as large as the previous values. Main chain scission occurs predominantly at the structure of 1, 2 diol linkage, partially at other structures.
G-value for the production of carbonyl groups in PVA was about 2. When the samples were kept at 100°C for a few minutes after irradiation, the G-value was reduced to 1. Since the increase in number of carbonyl groups produced by γ-ray irradiation is larger than that of main chain scission, it can be concluded that the produced carbonyl groups are ketone type in main chain.

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Viscosity of the solution increaes by irradiation of the system. The critical concentration for gel formation was 0.17 g/100 ml or less. The critical irradiation dose for gelation decrease linearly with the PVA concentration. In this case no minimum value in radiation dose was observed. At the critical concentration all PVA molecules may be in contact with each other.
Based on the critical concentration, the radius of PVA molecule of P 1500 was calculated 200Å or more in aqueous solution.
In presence of some organic compounds such as ethanol, ethylamine, dioxane and phenol, the gel formation was inhibited and scission of main chain was obserbed. In the PVA molecule irradiated in presence of ethylamine, the fragments of ethylamine combined were detected by the dinitrofluorobenzene addition reaction.
Depression of viscosity was observed when PVA aqueous solution is irradiated at the concentration below 0.17 g/100 ml, but in this phenomenon main chain scission is not responsible. Several salts e. g. KCl, Al (NO₃) ₃, CuSO₄ etc and acid were observed to react for salting out of the solution, but several basic salts such as Na₂CO₃, Na₂HPO₄ and NaOH do not. The formation of spherical micro gel was confirment by the light scattering measurments. The solutions irradiated with high dose became yellowish color in alkaline. Two weak absorption bands were observed at 240 and 290 μs respectively.
These may be attributed to the absorptions of _??_and _??_.

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