Showing papers by "Chiba Institute of Technology published in 1980"

Studies on the graft polymerization of carbon fibers. I. The graft polymerization of acrylate monomers and their properties

Abstract: Graft polymerization was carried out on carbon fibers subjected to various types of oxidation treatment and on acrylate (methyl, ethyl, and n-butyl) with benzene solvent and mainly benzoyl peroxide as initiator according to the nitrogen-displacement sealed-tube polymerization method. In comparison with carbon fibers subjected to air oxidation treatment, carbon fibers subjected to nitric acid oxidation treatment showed easier graft polymerization, and grafting became easier with increasing degree of nitric acid oxidation. The following relationship is established between the graft reaction ratio (a) and the polymerization time (t): da/dt = K(100−a). For graft polymerization with lauroyl peroxide (LPO), benzoyl peroxide (BPO), and α,α′-azobisisobutyronitrile (AIBN) as initiator, LPO showed the largest transfer reaction constant, followed by BPO; AIBN showed the smallest value. Grafting showed a tendency to become easier for monomers with a larger displacement radical group. For the graft polymerization reported in this article, it was believed that the affinity between carbon fibers subjected to oxidation treatment and to monomer influenced the result. For graft polymerization using acrylic acid as the comonomer, percent grafting increased notably. It is believed that, in this, in this case, apparent grafting by dipole-dipole interaction of the COOH group of the carbon fiber subjected to oxidation treatment and the COOH group of the polymer occurs according to the theory of Riess et al. Tensile strength and breaking elongation of graft carbon fibers showed a tendency to increase with an increase in percent grafting, whereas Young's modulus showed a tendency to decrease. The contact angle with water showed a tendency to increase with increasing percent, whereas the contact angle with ethylene glycol and phenylglycidilethyl showed a tendency to decreasing percent grafting.

Automatic Recording Laser Interferometer for Line Standards up to 2 m

Abstract: A description is given of an automatic recording laser interferometer for calibrating line standards up to 2 m based on Eppenstein's principle, and various factors which limit the measuring accuracies are also investigated in detail. This fringe-counting interferometer uses two corner cube reflectors. One reflector is mounted with the objective of a photoelectric miscroscope on a carriage which moves at a uniform speed of 10 to 300 mm/min on an air track. An electric pulse, which corresponds to the center of a graduation line and is a gate signal for counting interference fringes, is produced by the zero crossing method from the derivative of a signal obtained when the graduation line image goes across a slit. The reflectors generate two different interference fringes in phase quadrature by using their polarization properties in reflection, so that fringe resolving power is raised to λ/16. The experimental results on line standards show that the standard deviation of a graduation line positioning is 0.04 μm and the accuracy of measurement on a 1 m line-interval is 0.08 μm in standard deviation.

Effect of Various Target Molecules on a Charge Transfer Process C6H62+ → C6H6+

Abstract: Various target gases, helium, neon, argon, krypton, xenon, methane, ethane, propane and n-butane, were introduced into first field-free region of a Mattauch-Herzog double focusing mass spectrometer in order to investigate the effect of the pressure and the properties of the target gases on a charge transfer process C6H62+ → C6H6+ at the region. The amount of C6H6+ produced increased linearly with the pressure of the target gas, as has been reported, and was found to be closely related with the ionization potential of the target gas. The mechanism of the C6H6+ ion production is investigated by the concept of curve crossing.