Fatigue mechanism of polymer blends was investigated by measuring the dynamic viscoelasticity of the samples fatigued by using a cyclic stress tensile machine. Measurement was carried out for poly (vinyl chloride) -nitrile rubber (I), poly (methyl methacrylate) (II) -I and polystyrene-I blend systems. Change in the viscoelastic property by fatigue test depends on the sorts of the plastics, e. g., the loss modulus E″ of II-I decrease remarkably in the low temperature region (<0°C) and approach to that of II. This fact shows that cyclic stress weakens molecular interaction between II and I in the blends.

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Acetylation of cellulose membrane regenerated from commercial triacetyl cellulose membrane was carried out by soaking the membrane in acetyl anhydride-benzene-sulfuric acid mixture at room temperature. It was suggested that the membrane obtained by this method does not have a layer structure but a rather homogeneous one. As the acetylation reaction proceeded, the water flux decreased and the salt rejection increased. The water flux and salt rejection of these membranes were 1.6×10^-5g/cm²·sec and 93%, respectively. These values did not change during the continuous reverse osmosis experiment for 20 hours. The mechanism of permeation of water and salt through these membranes was discussed.

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To remove defects of the conventional diffusion cells, a new type of cell and an apparatus for boundary formation were constructed. This cell, which is leak-proof and contains no sliding parts, consists of an ordinary spectrophotometer cell with a container at top. As a seal between the upper and lower compartments, a small ball rests at the joint. After the cell has been filled with a solution up to the narrow joint, the solvent is gently added to the upper compartment. When thermal equilibrium has been attained, a capillary is introduced into the joint and moved downwards in the cell to suck the liquid at the boundary. To obtain symmetrical flow at the boundary which moves with the capillary tip, the apparatus is designed to pump out equal volumes of solvent and solution. Experiments showed that the new cell worked well for diffusion measurements on dilute polymer solution.

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Mechanism for reinforcement in the blend polymer of calcium carbonate (I) and polypropylene (II) grafted with maleic anhydride (III) was investigated. Scanning electron microscopy of fracture surfaces showed that I was encapsulated with II and fracture occurred mostly in the matrix material. When the blend polymer was extracted with xylene, a part of I passed through the filter paper together with II. These results demonstrate excellent affinity between I and II. From the structure analyses of the polymer, it is infered that the cause of the excellent affinity is not the formation of intermolecular ionic crosslinking but the formation of half salts comprising I partially neutralized by III grafted on II. The formation of the half salts is due to low grafting of III and low ionic dissociativity of I.

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Poly (hexamethyleneazobiscyanopentanamide) was synthesized by the interfacial polycondensation of azobiscyanopentanoyl chloride and hexamethylenediamine at room temperature. Similarly, copolyamide (I) consisting of the segments of the above polyamide (II) and nylon 6·10 was also synthesized. The azo group in the main chain of II and I was decomposed as easily as it was in ordinary azo-initiators (e. g., AIBN) both in solid state and in solution. When the thermally unstable II (or I) dissolved in DMF or m-cresol was heated in the presence of a vinyl monomer such as styrene (III), a block copolymer consisting of poly-III and degradable II (III-II) was obtained and its molecular weight increases remarkably with time in the early stage of polymerization. It was considered that the anomalous increase in molecular weight was due to the successive scission of azo group in the polymer chain followed by the growing reaction of III. Furthermore, a second vinyl monomer such as methyl methacrylate (IV) could be polymerized with III-II used as an initiator, yielding a block terpolymer (III-II-IV).

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Homopolymerization and copolymerization of N-(2-fluorenyl) -maleimide (I), N-1-(4-acetoxynaphtyl) -maleimide (II) and N-2-(9-acetoxyfluorenyl) -maleimide (III) were carried out at 60°C by using azobisisobutyronitrile (IV) as an initiator in tetrahydrofuran. The initial rates of the polymerization were R_p=k [I] ^2.11 [IV] ^0.64, R_p=k [II] ^2.26 [IV] ^0.72 and R_p=k [III] ^1.76 [IV] ^0.52 where k is rate constant. The over-all activation energies (E) and frequency factors (A) measured were E=26.4kcal/mol (I), 23.3 kcal/mol (II), 22.8kcal/mol (III) and A=3.4×10¹⁵ (I), 2.7×10¹¹ (II), 1.5×10¹¹ (III). The reactivity ratios in the copolymerization of N-(substituted) -maleimides with methyl methacrylate (V), were determined and the Q and e values were calculated as r₁=0.24, r₂=0.93, Q₁=0.43, e₁=1.82 for I (M₁) -V (M₂); r₁=0.17, r₂=2.29, Q₁=0.51, e₁=1.37 for II (M₁) -V (M₂), and r₁=0.068, r₂=1.34, Q₁= 0.87, e₁=1.90 for III (M₁) -V (M₂).

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The mechanical performance of polymers in voids and cellular parts of wood was studied for the following WPC systems; (a) PMMA (poly (methyl methacrylate)) -WPC polymerized by electron beam irradiation, (b) PMMA-WPC by injection of PMMA. Moreover, the change of molecular weight distribution (MWD) of PMMA in (a) was investigated. (1) E′ and E″ of wood increased by injection of PMMA, while they were not affected by PMMA in the cellular parts of (a) below 170°C. By the injection, the E″ peak of PMMA (85°C) shifted to heigher temperature side (120°C), while in the case of (a) the E″ peak of wood (230°C) shifted to lower temperature side (220°C) by PMMA in the cellular parts. (2) The molecular weight of extracted polymer by hydrolysis of the holocellulose increased with increasing moisture content of the system before irradiation. MWD of the grafted chains was narrower than that of the homopolymer. The above results suggest that the polymerization proceeded along the paracrystalline cellulose and hemicellulose matrix under irradiation.

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Copolymers of _L-alanine and N-methyl-_L-alanine (I) were synthesized by the heterogenious polymerization of their N-carboxyanhydrides in acetonitrile. Their conformations were studied in dichloroacetic acid trifluoroacetic acid (II) and in the mixed solvents of II-chloroform by the optical rotatory dispersion and nuclear magnetic resonance (¹H-NMR) methods. It has been found that I units incapable of forming hydrogen bond are not incorporated into the α-helix formed by _L-alanine sequences but their introduction into the poly-_L-alanine chain decrease the number of the hydrogen bonds by 2-10 per I unit, depending on I content. The results of NMR have shown that the mobility of the helix-coil junctions of the copolymer chains is different from that of poly-_L-alanine. Partial helical nature of the copolymer chains has been discussed as a function of I content.

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Effects of grafting of high-density polyethylene (I) on the properties of blend polymer filled with CaCO₃ (II) were investigated. The mechanical strength of the blend polymer was improved by the grafting with a small amount of maleic anhydride in an extruder. II was encapsulated with I, which improved the affinity between II and I. Water retards the grafting reaction to decrease the mechanical strength of the blend polymer. The inactivation of I radical and the formation of maleic acid with low grafting activity by water seem to be the causes of this retardation. Molecular weight of I was not affected by water.

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