Carbon fiber reinforced nylon 66 was molded by an injection machine. The fiber orientation was determined for the molded articles. In the low fiber content (∼15wt%), the fiber was oriented to the flowing direction of the resin. However, in the high fiber content, the fiber was only oriented in the center of the articles, and disoriented in the surface layer. The elastic modulus and the tensile strength of the articles increased with the fiber content, but the elongation at break decreased drastically with the increase of the fiber content. Namely, the behavior changed from ductile fracture to brittle one.

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The possibility of making optically uniform PET film in film plane has been theoretically investigated in a tenter process. The result shows that it is possible to make birefringence-free or optically uniform films, only by a simultaneous process, and not by a step-wise process. However optically uniform films can not be produced, if they undergo a heat setting process after stretching because molecular orientation is regenerated during this heat setting process

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Effects of zeolite on mechanical and thermal properties of composite materials in which matrix polymer is polycarbonate (PC) have been investigated using a dynamic viscoelastic method and thermogravimetry. The clinoptilolite-type zeolite powder was mixed with the PC polymer of number average molecular weight (M_n) of 24000 at various concentrations for preparing the composites desired. In the composite containing 3wt% zeolite powder, the matrix PC polymer reduced its M_n down to the value of 13000 after the mixing procedure at 280°C, accompanying with decreasing the α_a absorption temperature of the composite loss modulus spectra from 158°C to 152°C and with shifting the onset of decrease in the storage moduli to lower temperaature. However, the activation energy of the glass transition in the composite was independent of the changes in M_n of PC, probably due to the polydispersity of PC molecules by the preseuce of zeolite materials. On the other hand, the activation energy of the PC decomposition decreased proportionally to the value of M_n; this comes from the catalystic effect of acidic zeolite to the decomposition reaction at the mixing temperature. It will be required for the zeolite powder with the surface treatment by suitable coupling agents when utilized as a composite filler to prevent from the decomposition of matrix polymer.

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