All issues
Predecessor
Volume 48, Issue 2
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
Ryohei TAKIGUCHI, Toshiyuki URYU1991 Volume 48 Issue 2 Pages 61-66
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSSurface hardness and friction properties of the poly (methyl methacrylate) (PMMA) -monomer system irradiated by low-energy electron beams (EB) are investigated, The hardness of the monomer system irradiated by EB depended on the molucular weight/functionality value. The monomer system with a stearyl group showed a low friction coefficient and the monomer system with a hydroxyl group showed a high value. In the PMMA-monomer system irradiated by EB, the film had intermediate hardness and friction coefficient values, between those of PMMA and those of the monomers irradiated by EB. In the PMMA-monomer with a stearyl group system, the friction coefficient decreased considerably. The results suggest that the concentration of the monomer with a stearyl group increased at the polymer surface and the monomer was polymerized on the surface by EB. The friction coefficient and the contact angle of the polymer surface also depended on the annealing condition before EB irradiation. It was found that the surface properties of cured film are greatly infiuenced by the compatibility of the polymer with the monomer and the polymer therefrom polymerized in the polymer-monomer system.View full abstractDownload PDF (931K) -
Shintarou KANBAYASHI, Takaaki ARAI1991 Volume 48 Issue 2 Pages 67-73
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe pH titration was made at various temperatures for two compounds with different densities of charged groups, carboxymethyl cellulose (CMC-H) and partially anionized polyacrylamide (PAAm-H). The effects of the density of charged groups and temperature on the ionization were quantitatively investigated by determining the apparent ionization constant (Kapp) and the variation of electrostatic free energy of ionization (ΔGiel). The result indicates that pKapp increases for CMC-H and the PAAm-H series with low density of charged groups as the temperature increases. The ΔGiel values for both CMC-H and PAAm-H are proportionate to the density of charged groups. The value of ΔGiel for CMC-H increases with an increase in temperature. As the temperature increases, however, ΔGiel decreases for the PAAm-H series with high density of charged groups, while that for the PAAm-H series with the low density is constant as low as 1/10 that for other series. It became clear that such a relationship between the temperature and ΔGiel reflects the temperature dependence of the dielectric constant and polymer chain flexibility.View full abstractDownload PDF (1208K) -
Takafumi YAMAMIZU, Osamu NAGANO, Keishi TADA, Kunihiko TAKEDA1991 Volume 48 Issue 2 Pages 75-80
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPorous crosslinked polymers carrying sulfonic acid groups were prepared with varying degrees of crosslinking and pore structures. The ratio of number of macropores (here named “fixed pores”) to total number of pores was named fixed pore ratio φih; pore structures were characterized by this φih. Ion exchange properties of synthesized cation exchangers were found to be different according to the physical structures of polymers. Polymers with high φih (compact polymer phase and high crosslinkings density) were found to show very slow ion exchange rates. In the Nd3+/Pr3+ system using the polymer with φih=0.94, the degree of conversion after 60min was 0.622 and about 40% of counter ions did not exchange. From these phenomena, we concluded that rigid and unflexible polymer chains formed very stable trapping field partially in the ion exchange site.View full abstractDownload PDF (1112K) -
Hiroshi SAKAI, Takeshi KITANO, Tetsuo NISHIMURA1991 Volume 48 Issue 2 Pages 81-88
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSMelt rheology of incompatible binary polymer blends was investigated with capillary flow measurements and dynamic flow ones. Various factors which influence the rheological properties of the polymer blend system wereinvestigated to establish the evaluation of melt rheology for this system. Samples were binary polymer blends consisting of polycarbonate (PC) and linear low density polyethylene (LLDPE). Measurements were carried out under the same conditions to compare the data obtained from each rheometer. A discrepancy between two capillary rheometers was found for the steady shear flow data. The results of dynamic flow measurements of two rotational rheometers with cone plate also showed some discrepancies. However, these were smaller than those of the capillary flow measurements. There was a clear difference between the data of the cone plate instrument and those of the parallel plate one. The measured values of the parallel plate were higher than those of the cone plate over the entire range of blend compositions. Thus in PC/LLDPE blend systems, experimental conditions must be clearly stated, because rheological properties are strongly affected by blend composition, temperature, and the geometry of the test fixture.View full abstractDownload PDF (1294K) -
Minekazu KODAMA1991 Volume 48 Issue 2 Pages 89-95
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effects of thermal modification on the structural properties were studied by dynamic viscoelasticity, infra-red spectroscopy and X-ray diffraction for blends of a liquid crystalline copolyester consisting of p-hydroxybenzoic acid (PHB) and poly (ethylene terephthalate) (PET) and phenoxy resin. Poor miscibility and phase separation between the blend components can be observed for viscoelastic properties of samples moulded at 260°C over the whole composition range studied. The miscibility of the blends is increased by moulding at 280°C, and the blends moulded at 300°C show the same sort of viscoelastic behavior as the homogeneous blends. These changes are accompanied by an interchange reaction between the blend components. The rubbery equilibrium modulus can be observed for the blends moulded at 300°C.View full abstractDownload PDF (1156K) -
Toshiyuki KODAIRA, Kazuhiro SHINAGAWA1991 Volume 48 Issue 2 Pages 97-103
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSTelechelic polysiloxanes with mesogenic side chains (TLS) were synthesized and their reactions with chelic pelymers were investigated. Functional end groups introduced to TLS were OH. Telechelic polymethylhydrosiloxane (THS) was obtained by acid-catalyzed ring-opening polymerization of 1, 3, 5, 7-tetramethylcyclotetrasiloxane in the presence of an end-capping agent with two OH groups protected with the trifluoroacetyl group. THS was used for hydrosilylation of mesogenic compounds with an allyl group using a platinum catalyst. After removing trifluoroacetyl groups, addition reactions of the TLS with the polymers having an isocyanate group at one end were carried out to give ABA type block copolymers. The highest value of A/B obtained was 1.3 which was obtained when polyethylene glycol monooleyl ether capped with the isocyanate group at its end (degree of polymerization of polyethylene glycol unit, 50) Was used as a chelic polymer. The reactivity of TLS is strongly dependent on the mesogenic side chains, and the stncture of chelic polymers influences the reaction. These results suggest that the conformations of the TLS and chelic polymers play important roles in their reactions. Thermal property of the block copolymer was also examined.View full abstractDownload PDF (1268K) -
Toru OSHIMA, Kenichi ICHIKAWA, Shigeru TASAKA, Norihiro INAGAKI1991 Volume 48 Issue 2 Pages 105-110
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe structure and thermal properties of copolymers of maleic anhydride and alkyl vinyl esters (CH2=CHOCOCnH2n+1, n=1 to 17) were investigated by X-ray diffraction and DSC. In spite of the perfect alternating sequence of the comonomers, the copolymers were glassy polymers because of the atacticity of vinyl esters in the polymer sequence. The glass transition temperatures of these polymers were almost in the same level near 130°C. X-Ray diffraction patterns suggested that the layered structure having tilted side chains was formed by aggregation between polar groups. On doping with tricresyl phosphate as a plasticizer, the spacing between the layers increased steeply in the polymer with such long side chain as vinyl stearate. This phenomenon suggests that the long alkyl ester copolymers can be intercalated with the plasticizers.View full abstractDownload PDF (1068K) -
Minoru NAGATA, Tsuyoshi KIYOTSUKURI1991 Volume 48 Issue 2 Pages 111-117
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSHydrochlorides of glutamic acid diethylester and lysine were copolymerized to nylon by melt-polycondensation. Nylon 66 copolymers and nylon 610 copolymers containing up to 30mol% of gultamic acid unit could be prepared. Nylon 6 copolymers and nylon 610 copolymers containing up to 15-40mol% of lysine unit could be prepared. With increasing comonemer content, the reduced specific viscosity, melting point, crystallinity and heat resistance decreased, while glass transition temperature, cold crystallization temperature, and density increased. Solubility of the copolymers having high lysine content increased in polar solvents. Copolymers with the comonomer content of 1-2mol% had higher moisture regain and remarkably higher dyeability for an acid dye in comparison with their homopolymers. Some discussions were made on these results.View full abstractDownload PDF (1180K) -
Hiroaki EGAWA, Takamasa NONAKA, Tatsuo YAMAGUCHI, Hiromi HIGASHI1991 Volume 48 Issue 2 Pages 119-122
Published: February 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESS2, 3-Epithiopropyl methacrylate-p-chlorostyrene copolymers were prepared by solution pdymerization in benzene. The molecular weight and the composition of the copolymers were determined by gel permeation chromatography and the chlorine content of the copolymers, respectively, The copolymers were fractionated by the addition of n-butanol to a copolymer solution in benzene. The glass transition temperature (Tg) was detemined by differential scanning calorimetry. The TTg of the copolymers increased with increasing molecular weight and p-chlorostyrene moiety in the copolymers. The relation between Tg and 1/MTw gave a straight line for each copolymer. The unfractionated and fractionated copolymers showed almost the same TTg.View full abstractDownload PDF (551K)
- |<
- <
- 1
- >
- >|