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Volume 40, Issue 10
Displaying 1-18 of 18 articles from this issue
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Takayuki OTSU, Akira KURIYAMA, Masatoshi YOSHIDA1983 Volume 40 Issue 10 Pages 583-588
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe polymerizations of vinyl monomers with radical initiators (iniferters) which have both functions for chain transfer and terminator, proceed via a living radical mechanism to give polymers with iniferter fragments bonded at their chain ends. These polymers can serve further as a polymeric iniferter. Such a concept and reaction were applied to the synthesis of the block copolymers by using tetraethylthiuram disulfide (TD), and diphenyl disulfide (DPD), diphenyl sulfide (DPS), and benzoyl disulfide (BD) as photoiniferter. The photopolymerizations of methyl methacrylate (MMA) with TD and of styrene (St) with DPS were observed to proceed via a living radical mechanism. Similar results were also found for photopolymerizations of St with TD and DPD. However, the photopolymerizations of MMA with DPD and DPS, and of St or MMA with BD were found to deviate from a living radical mechanism. When the St polymers obtained from the former system were used as polymeric iniferters, the photopolymerization of MMA also proceeded via a living radical mechanism and the block copolymers were produced with high block efficiency. However, photopolymerizations with polymeric iniferters obtained from the latter system gave block copolymers with a low efficiency.View full abstractDownload PDF (995K) -
Ryuzo ASAMI, Mikio TAKAKI, Masayoshi ICHIKAWA, Toru ICHIE1983 Volume 40 Issue 10 Pages 589-594
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe graft polymerization of a-amino acid NCAs onto vinyl polymers was performed. NCA monomers such as DL-phenylalanine NCA, r-methyl-L-glutamate NCA and L-valine NCA, were polymerized with styrene-vinylbenzylamine or methyl methacrylate-vinylbenzylamine copolymers as polymer initiators, using nitrobenzene, dioxane and tetrahydrofuran as solvents. These polymeric initiators of benzylamine type polymerized the NCA monomers to high conversions and the initiator efficiency of the initiators was shown to be nearly quantitative. The graft polymers prepared were found to have about 10 pendant oligopeptides on the main chain of vinyl polymer.View full abstractDownload PDF (889K) -
Yoshiharu KIMURA, Norihiro SUGIHARA, Isoji TANIGUCHI1983 Volume 40 Issue 10 Pages 595-601
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSHighly pure dimethyl esters of carboxyl functionalized poly (oxyethylene) (PEO acid) were prepared in quantitative yield by HCl-catalyzed reaction of the corresponding acids with 2, 2-dimethoxypropane at room temperature. The products (called “PEO ester”) showed sharp molecular weight distribution at Mn=400, 1, 000, 3, 300, and 8, 400. They were unique and useful telechelic polymers for the synthesis of tailor-made multiphase materials involving poly (oxyethylene) chain. In the present study were examined polycondensations of PEO ester with ethylene glycol and with polyethylene glycol (PEG) producing high molecular weight polymers interlinking poly (oxyethylene) segments, as well as copoly-condensations with polytetramethylene glycol to give novel block copolyethers. PEO ester was also utilized for the synthesis of segment block copoly (ester-ether) based on poly (ethylene terephthalate) (PET).View full abstractDownload PDF (1206K) -
Isao IKEDA, Kimihiro SUZUKI, Kiyotaka ISHIGURO1983 Volume 40 Issue 10 Pages 603-607
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNylon 6 was metallated with alkali metal methoxide in hexamethylphosphoramide and then graftcopolymerized with vinyl monomers such as methyl vinyl ketone (MVK), acrylonitrile (AN), methacrylonitrile (MAN), methyl acrylate (MA) and methyl methacrylate (MMA). The grafting ratios increased in the order MAN>MA>MMA>AN>MVK. High grafting efficiency was obtained with MMA and MAN containing a methyl group on the a-carbon. The grafting rations also increased with increase in the degree of methoxide addition to nylon 6 and monomer concentration and decreased with increasing electronegativity of alkali metal. In the graft copolymerization of methacrylate esters onto nylon 6, the grafting ratios increased with increasing the substituent constant of ester alkyl groups. A differential thermal analysis showed that the ease of crystallization of nylon 6 components in the copolymers was different with the kinds of branch polymers.View full abstractDownload PDF (850K) -
Tsuyoshi KIYOTSUKURI, Khosrow JAMSHIDI1983 Volume 40 Issue 10 Pages 609-613
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNylon 66-61 copolymers (I, isophthalic acid) and nylon 66-MXD6 copolymers (MXD, m-xylylene diamine) were prepared by melt polycondensation (MP) and by interfacial polycondensation (IP) using CCl4 as organic solvent. Melting temperature (Tm), glass-transition temperature (Tg), and cold crystallization temperature (Tcc) of the copolymers were measured by a differential thermal analyzer. Density measurement, X-ray analysis, and dynamic viscoelasticity measurement were carried out for films prepared by casting from formic acid solutions. The copolymers prepared by IP had lower Tm and higher Tg, Tcc, and dynamic modulus than the copolymers prepared by MP. These results indicated that the copolymers prepared by IP form a block structure which enhanced the rigidity of copolymer chains. The 6I copolymers had lower Tm and higher Tg, Tcc, and dynamic modulus than the MXD6 copolymers, which suggested the effect of benzene ring adjacent to amide group on the rigidity of copolymer chains.View full abstractDownload PDF (813K) -
Koji ISHIZU, Atsushi MURAKAMI, Takashi FUKUTOMI, Toshio KAKURAI1983 Volume 40 Issue 10 Pages 615-621
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPolystyrene (PSt) macromers having several vinyl groups at the ends were synthesized by the mechanical scission reaction of the main chain in the presence of p-divinylbenzene (p-DVB). (PSt-poly-4-vinylpyridine (P4VP)) sequence copolymers with different composition and number of branches were prepared by the radical copolymerization of PSt macromer with 4VP. The morphological observation of these sequence copolymers was carried out by the transmission electron microscopy and was compared with the previous results on poly (St-block-4VP) s having a sharp distribution of molecular weight. As a result, the microphase separated structures of these sequence copolymers having several numbers of branches showed spherical domain, irrespective of the volume fraction of the phases.View full abstractDownload PDF (1670K) -
Kuniharu KOJIMA, Tomohiro NOMURA, Satoshi TAKEDA, Masako YOSHIKUNI1983 Volume 40 Issue 10 Pages 623-628
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSGraft copolymerization of methyl methacrylate (MMA) onto saponin, contained in seed plants, was investigated using tributylborane (TBB) as initiator in aqueous media. Both the percentage and the efficiency of grafting greatly increased with increasing saponin content. The percentage of grafting attained a maximum at about 35°C, although the total conversion increased with raising polymerization temperature. The saponin graft copolymer was found to adsorb metallic ions such as Cu2+. The adsorption of Cu2+ showed the maximum at pH 6.View full abstractDownload PDF (1116K) -
Kingo ITAYA, Kiyomi SUGAWARA, Kunio ARAI, Shozaburo SAITO1983 Volume 40 Issue 10 Pages 629-635
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe radical-induced grafting of styrene onto polybutadiene with very narrow molecular weight distribution has been studied. The polybutadiene graft efficiency (GF (PB)) can be directly measured by the GPC analysis. The rate of grafting reaction is remarkably affected by the phase-separation in the bulk polymerization. This fact supports that the grafting process occurs mainly through a chain transfer. An expression relating the rate of the grafting reaction with the initiato concentration can be explained by the grafting process through the chain transfer. An experimental data is fairly consistcnt with this equation.View full abstractDownload PDF (2075K) -
Hae Jinn KIM, Kenji MOGAMI, Munenori SAKAMOTO, Hiroaki TONAMI1983 Volume 40 Issue 10 Pages 637-643
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSABSTRACT: Polymer complexes were precipitated from aqueous solutions of poly (methacrylic acid) (PMAA) of different tacticities and poly (ethylene oxide) (PEO) when the pH of the solutions was adjusted to pH 2. The monomer unit molar ratio of PMAA and PEO in the precipitates was 1 : 1 for atactic PMAA-PEO system and 1 : 0.25 for isotactic PMAA-PEO system, and the ratio increased up to 1 : 1.8 with increasing syndiotacticity of PMAA. The ir spectra of films made from dimethyl sulfoxide solutions of the precipitates as well as these from the solutions of the blends of PMAA and PEO in various compositions indicated that hydrogen bonds between the carboxyl group of PMAA was increased. An ordered X-ray diffraction pattern was observed only for the precipitates from PMAA of a high syndiotacticity. It was estimated by statistical analysis that the minimum syndio tactic diad sequence length of PMAA needed to form a highly ordered polymer complex system was about 7 monomer units. It was suggested that syndiotactic PMAA and PEO formed ladder-type polymer complexes by cooperative interaction between PMAA and PEO, while atactic PMAA-PEO formed scramble-type polymer complexes.View full abstractDownload PDF (1646K) -
Masaru MIYA, Susumu YOSHIKAWA, Reikichi IWAMOTO, Seiichi MIMA1983 Volume 40 Issue 10 Pages 645-651
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSMechanical properties of poly (vinyl alcohol) (PVA) -chitosan blend films have been studied. The degree of deacetylation was 93 (L3F) and 99% (H3F) for the chitosan used, while that for PVA was 98.5%. The blend films show not only larger tensile strengths than the additive values of the individual components but also a maximum value appears at 15-30% content of the chitosans. The appearance of the maximum tensile strength at a specified chitosan content is clearer in the wet state than in the dry state. The characteristic feature is more distinct for the blend film that contains L3F chitosan than for that containing H3F. Electron microscopic observation of the blend film proves complete compatibility of the two components at the composition showing the maximum. All the experimental facts obtained in the present study suggest the existence of some specific intermolecular interactions between PVA and chitosan in the blend.View full abstractDownload PDF (1203K) -
Tetsuo MITANI, Katsuyoshi IISAKA1983 Volume 40 Issue 10 Pages 653-659
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPolypropylene (PP) and Polystyrene (PS) were blended mechanically with Styrene-butadiene-styrene block copolymer (SBS) in molten state. The steady melt flow properties and dynamic viscoelastic properties were measured for the two systems of blends (PP/SBS and PS/SBS). Morphology was observed by means of transmission electron microscopy. Blending of SBS increases the viscosity, and this effect is greater on PS/SBS than on PP/SBS when SBS content and shear rate are low. The moduli for the blends obey a general mixing equation for blends consisting of two continuous phases, when the SBS phase is dispersed in the matrix polymers. The exponents of the equation and the connectivities of the matrix polymers obtained by Nielsen's model are less for PS/SBS than for PP/SBS. These results are explained by the different morphologies. The SBS phase in PS matrix has a stronger tendency to become a continuous phase than the phase in PP matrix.View full abstractDownload PDF (1260K) -
Tadaya KATO, Noriaki KOBAYASHI, Akira TAKAHASHI1983 Volume 40 Issue 10 Pages 661-666
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSStatic light scattering measurements were carried out on concentrated tetrahydrofuran solutions of the copolymer blends. The copolymer blends were made of sytrene-maleic anhydride random copolymer (SMA) and acrylonitrile-styrene random copolymer (AS). Using Debye-Bueche plots and Guinier plots, correlation distances (a) and radii of gyration (RG) were determined from the experimental results of light scattering. The compatibility of the copolymer blends is discussed on the basis of the composition dependences of the phase separation in solutions and in casting films. The phase separation behavior was observed by the visual inspection of the turbidity. If the styrene contents (mole fractions) of both SMA and AS copolymers are nearly equal, the copolymer blends of SMA/AS are compatible over almost the entire composition of the blends.View full abstractDownload PDF (1031K) -
Masayuki KASAJIMA, Atushi TAKAHASHI1983 Volume 40 Issue 10 Pages 667-672
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSRelationships between morphology and method of cooling from molten state to solid state in incompatible polymer blends have been investigated. Two cooling methods are employed. One is the fast cooling method, immersing the sample in liquid nitrogen. The other is the slow cooling method, leaving the sample at room temperature. Morphologies of the polymer blends have been observed by a scanning electron microscope. The combinations of polymers in our blends are : polypropylene (PP) -polymethyle methacrylate (PMMA), high-density polyethylene (HDPE) ·PMMA, and PP·polystylene (PS). At weight fraction (c) =0.25, remarkable changes of the morphology were found. The higher the kneading temperature and the slower the cooling rate, the larger was the size of the dispersed phases in PP·PS and HDPE·PMMA blends of c=0.50.View full abstractDownload PDF (3379K) -
Fumio HOSOI, Takashi SASAKI, Miyuki HAGIWARA1983 Volume 40 Issue 10 Pages 673-682
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSEmulsification of the epoxy resins, onto which hydrophilic groups were introduced by simultaneous co-graft polymerization with electron beam irradiation, were studied. Resins modified with use of ionic monomers such as methacrylic acid (MAc), diethylaminoethyl methacrylate (DE), tetramethylammonium methacrylate (TMAMA), or methacryloyloxyethyltrimethyl ammonium chloride (QDM) formed latexes, when they were dissolved into small amounts of solvents followed by the addition of water. A higher composition of hydrophilic monomer in the resin-monomer mixture gave a latex with a smaller particle size and higher storage stability. TMAMA and QDM, both of which were incompatible with epoxy resin, were very effective in decreasing the particle size and increasing stability of a latex. It was also ascertained that an alkyd resin were able to emulsified similarly by grafting of 2-hydroxyethyl methacrylate and MAc.View full abstractDownload PDF (3375K) -
Yousuke MORITA, Miyuki HAGIWARA1983 Volume 40 Issue 10 Pages 683-690
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTo improve the radiation resistance of dimethyl silicone rubber (DMS), the effects of blending with ethylene-propylene-diene terpolymer (EPDM) or tetrafluoroethylene-propylene copolymer (Copoly (TFE-P)) were studied. DMS was mixed mechanically with one of the above rubbers and a radical initiator. The mixture was molded at 160°C under a pressure of 100kg/cm2 for 30min. Radiation resistances of these rubber blends were evaluated by measuring tensile and viscoelastic (torsion pendulum method) properties of sample sheets irradiated by cobalt 60 up to 200 Mrad (Dose rate, 0.5 Mrad/h) in air at room temperature.
In DMS-EPDM blends, the radiation resistance increased monotonously with increasing volume content of EPDM because of the contribution of the higher radiation resistivity of EPDM. On the other hand, DMS-Copoly (TFE-P) blend had its maximum radiation resistance at 1 : 1 volume ratio. When irradiated separately, DMS was hardened by cross-linking, and Copoly (TFE-P) was softened by oxidative degradation. The appearance of maximum radiation resistance in the blend DMS-Copoly (TFE-P) rubber was attributed to the balancing of properties due to the radiation effects due to crosslinking or chain scission occuring in the component rubbers.View full abstractDownload PDF (2053K) -
Hajime MIYAMA, Nobuyuki FUJI, Tatsuya NAKAMURA, Shoji NAGAOKA, Yuichi ...1983 Volume 40 Issue 10 Pages 691-696
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPolyacrylonitrile containing bromine atoms was synthesized by photopolymerization of acrylonitrile with carbon tetrabromide as an initiator. To the photosensitive polyacrylonitrile synthesized, methoxypolyethyleneglycol methacrylate and dimethylaminoethyl methacrylate were photografted. The graftpolymer was quaternized and heparinized. The water content, interfacial free energy, N+ concentration, and ethylene oxide content of the graftpolymers prepared at various feeding ratios were determined. The amount of platelet adhered on the quaternized and heparinized polymer was measured. Also, the amount of heparin released from the heparinized polymer in the aqueous NaCl solution was measured with soaking time. It was found that the excellent antithrombogenic polymer could be designed by controlling the composition of the photograftcopolymer.View full abstractDownload PDF (1387K) -
Kunio FURUSAWA, Yoshihiro KIMURA, Toru TAGAWA1983 Volume 40 Issue 10 Pages 697-702
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSMethod for preparing composite polystyrene latices including silica particles in the core, has been examined under the various conditions. It was realized that an important factor to control was one on the surface treatments of the silica particles used as the seed. In the case the bare particles of silica were used in the polymerization, there was no capsulation of polymer, and new polymer particles were formed in the aqueous phase. On the other hand, in the case polymer-coated particles which were made by adsorbing hydroxypropyl cellulose (HPC) on the silica at the lower critical solution temperature (LCST) were used, encapsulation of polymer molecules occured and fairly monodisperse composite latices were prepared. This result indicated that the dense adsorption layer of HPC formed at the LCST played as a binder between the silica particle and growing polymer molecule in the polymerization in the presence of silica particles. Furthermore, the degree of encapsulation was examined by analyzing the Gel-Permeation Chromatogram of the polymeric material produced from the composite latices.View full abstractDownload PDF (1633K) -
Mikio TAKAKI, Ryuzo ASAMI, Masayoshi ICHIKAWA, Toru ICHIE1983 Volume 40 Issue 10 Pages 703-706
Published: October 25, 1983
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe rate of polymerization of α-amino acid NCAs such as DL-phenylalanine NCA, γ-methy-L-glutamate NCA and L-valine NCA with styrene-vinylbenzylamine or methyl methacrylate-vinylbenzyl-amine copolymers was measured by the analysis of CO2 evolved. The rate was shown to be the first order of monomer concentration involving the quick initiation by polymeric amine in every solvents of nitrobenzene, dioxane and tetrahydrofuran (THF). The rate of polymerization of NCAs in nitrobenzene was much faster than that in dioxane or in THF. The rate of polymerization of NCAs with polymeric benzylamine initiator was 1.6-2.2 times as fast as that with benzylamine of low molecular weight initiator. This acceleration of the polymerization rate might be explained as “polymer domain effect”.View full abstractDownload PDF (570K)
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