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Volume 41, Issue 7
Displaying 1-9 of 9 articles from this issue
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Yukio OKADA, Yasuhiko OONO1984 Volume 41 Issue 7 Pages 371-375
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAlthough thiols, having large chain transfer constants are generally used as a regulator of polymerization degree, mercaptocarboxylic acid (MCA), such as mercaptoacetic acid (MAc) or mercaptosuccinic acid (MSuc), was found to initiate the radical polymerization of methyl methacrylate (MMA) in methanol. The overall activation energies for polymerization were 10. 9 kcal/mol (for MAc system) and 10.0 kcal/mol (for MSuc system), respectively. The following rate equations were obtained :
Rp=k [MMA]1.50 [MAc]0.35
Rp=k [MMA]1.45 [MSuc]0.42
The results indicated that the initiating radical was produced through the complex of MMA and MCA. The rate constants for chain transfer to MCA were evaluated as 0.48 for MAc and 0.42 for MSuc at 60°C, respectively.View full abstractDownload PDF (820K) -
Tatsuo WADA, Ryuichi OSHIMA1984 Volume 41 Issue 7 Pages 377-382
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFluorescence properties of the solid films of polymers doped with biscarbazolyl compounds have been examined. For a, ω-biscarbazolylalkanes, the monomer fluorescence is quenched and excimer fluorescence becomes prominent as the concentration increases. The intensity ratios of excimer emission to monomer emission are varied in the order of compounds in which two carbazole groups are bound by C6, C4, C10, C5 and C8 methylene chains. No sandwich excimer fluorescence could be observed in 1, 2-trans-biscarbazolylcyclobutane even at the highest accessible concentration. Thus the intramolecular interaction dominates the excimer formation in solid solutions of biscarbazolyl compounds in polycarbonate.View full abstractDownload PDF (867K) -
Tatsuo WADA, Ryuichi OSHIMA1984 Volume 41 Issue 7 Pages 383-387
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA study of carrier transport properties is reported for “bichromophores” molecularly dispersed in a polycarbonate. The concentration of Excimer-Forming Sites (EFS) can be controlled in dually molecularly doped polymers by adjusting the molar ratio of 1, 3-biscarbazolylpropane (1, 3-BCzP) to 1, 2-trans-biscarbazolylcyclobutane (1, 2-BCzB). The hole drift mobility of 1, 2-BCzB doped polymer which is free from excimer is higher by an order of magnitude than that of poy (N-vinylcarbazole). It greatly dropped by addition of a small amount of 1, 3-BCzP, which makes an intramolecular excimer. Thus EFS control the carrier transport as intrinsic structural traps.View full abstractDownload PDF (697K) -
Yukuo NANZAI1984 Volume 41 Issue 7 Pages 389-395
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSStress-strain curves obtained in step-extension tests on glassy poly (methyl methacrylate) were compared with S-S curves obtained at constant extension rates. It was found that ductility of the polymer decreased considerably when the polymer had been subjected to stretching at very low strain rates prior to the higherrate step extension. The fracture envelopes in the diagram of S-S curves of glassy PMMA also confirmed the deterioration in the ductility of the polymer during low-strain-rate extension. The decrease in ductility was closely associated with the brittle to ductile transition, i. e. the initiation of plastic flow, in the polymer. The reason for the decrease in ductility is discussed in terms of the strain-rate dependence of the magnitude of activation volume in plastic flow in the glassy polymer.View full abstractDownload PDF (1280K) -
Tsuguo HANEDA, Juzo TAKAHASHI, Haruji NOMURA, Masataka KUROKAWA1984 Volume 41 Issue 7 Pages 397-405
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to make clear the effect of rolling on the melting behavior of polytetrafluoroethylene (PTFE), samples of PTFE raw tape (R-tape) and of the tape stretched at high temperature (S-tape) were rolled to various proportions and then examined by thermal analysis (thermomechanical analysis (TMA) and differential thermal analysis (DTA)) and electron microscopy. The rolling has no significant effect on the TMA thermograms of R-tape. But for S-tape, the strong rolling had an effect resembling the short time sintering on the structure, and distinct differences appeared on the TMA thermograms. When PTFE samples were heated to various temperatures in the melting region, the DTA thermograms altered from the complex melting form containing shoulders to clear double peaks. The samples heated above the melting point gave a single peak like that of the sintered sample.View full abstractDownload PDF (1934K) -
Sadaatsu YAMAGUCHI1984 Volume 41 Issue 7 Pages 407-411
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFibrilar network structures are formed by drawing samples of unsintered PTFE tape. Electron microscopic observations were made to examine the structural changes of heat treatment of the drawn PTFE tape under fixed conditions. Periodical dents in the fibrils took place perpendicular to the fibrilar direction by heat treatment.
The edges of the band in fibrils heated under high tension were similar to those of the fracture surfaces of sintered bulk PTFE. Consequently, it seemed that the chain folding was formed in the fibrils by heat treatment of expanded PTFE under fixed conditions.View full abstractDownload PDF (1630K) -
Tetsuo NISHIMURA1984 Volume 41 Issue 7 Pages 413-420
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFlow characteristics of a polymeric system filled with a large quantity of inorganic powdered materials were studied by means of a cone-plate rheometer and a capillary extrusion rheometer. The viscosity of the filled-dispersed polymer is governed by the volumetric loading of filler φ under Brinkman's equation in the range of lower γ. The ratio of entrance pressure loss to apparent shear stress (Pc/τw′), which signifies an elastic property, increases with increasing γ, whereas the φ dependence of calcium carbonate is oppisite to that of mica. The die swell also depends upon φ and τw′, while in the case of calcium carbonate the effect varies markedly with the size of the particles. The surface treatment of the filler affects the flow in a capillary, enlarging η as φ becomes larger.View full abstractDownload PDF (1486K) -
Hidefumi HIRAI, Makoto KOMIYAMA, Toru MORI1984 Volume 41 Issue 7 Pages 421-424
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSCopolymerizations of polar vinyl monomers such as methyl methacrylate (MMA), methyl acrylate (MA), acrylonitrile (AN), metbacrylonitrile, and methyl vinyl ketone with electron donating monomers such as styrene, isoprene, 1-hexene, and vinyl acetate have been carried out in the presence of boron trichloride, in toluene at 0°C in dark with benzoyl peroxide as initiator. Alternating copolymers were obtained in the MMA-styrene, the MMA-isoprene, and the MA-styrene systems, using boron trichloride in a molar ratio 0.1 with respect to the polar vinyl monomers. The isoprene units in the MMA-isoprene alternating copolymer took 1, 4-structures without cross-linking. In other copolymerization systems, no copolymers were pre-pared. In a terpolymerization of the AN-MMA-styrene system using boron trichloride, AN exhibited strong retardation of the copolymerization.View full abstractDownload PDF (502K) -
Nobuhide YAHIRO1984 Volume 41 Issue 7 Pages 425-428
Published: July 25, 1984
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe copper (II) - (R) -2-ethylethylenimine complex, CuEEI, was synthesized, and its ultraviolet, visible, infrared spectra, optical rotatory dispersion and circular dichroism in methanol were measured. The binding ratio of copper (II) and (R) -2-ethylethylenimine was determined to be 4 by means of mole ratio method.View full abstractDownload PDF (548K)
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