巻号一覧
79 巻, 12 号
選択された号の論文の5件中1～5を表示しています
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貯蔵弾性率と網目鎖濃度および分子運動性の関係岩蕗 仁, 永田 員也, 野口 徹, 山田 英介2006 年 79 巻 12 号 p. 551-556
発行日: 2006/12/15
公開日: 2010/03/12
ジャーナル フリーPeroxide-crosslinked EPDMs were examined by dynamic mechanical analysis. In a rubbery state, a plot of storage modulus (E') vs. temperature gave an approximately linear relationship. The slope of the approximated line increased with an increase in apparent crosslinking density (νS) which was calculated from equilibrium swelling. However, E' of peroxide-crosslinked EPDMs were not proportional to absolute temperature (T). For the EPDMs crosslinked above 400mol/m3 of νS, straight lines approximating the relationships between E' and T gave a constant T-intercept at E'=0. This indicates that E' in a rubbery state is proportional to the difference between T and a reference temperature (T0). Assuming E' proportional to T-T0, effective crosslinking density (νS) was calculated from E' as T0=150K. Spinspin relaxation time of network component (T2n) and the fraction (Fn) were measured by 1H pulsed NMR with Hahn echo method. At each temperature, 1/T2n (or Fn/T2n) showed good linear correlation with E'. Over the temperature range 343 to 423K, the plot of 1/T2n (or Fn/T2n) vs. νE gave a straight line independent on the temperature at which E' and T2n were measured.抄録全体を表示PDF形式でダウンロード (955K) -
柳谷 奈津子, 寺井 英次, 大村 靖, 向井 喜一郎, 石田 健哲, 渡邊 智子, 大武 義人2006 年 79 巻 12 号 p. 557-561
発行日: 2006/12/15
公開日: 2010/03/12
ジャーナル フリーEthylene-propylene-diene rubber (EPDM) compounded with dicumyl peroxide (DCP) and modified polyphenylene ether (mPPE) are bonded directly without an adhesive on the conditions of rubber crosslinking. In this study, the mechanism of the direct adhesion between EPDM compounded with DCP and mPPE was investigated. In addition, polyamide 66 (PA66) and polyoxymethylene (POM) instead of mPPE were studied.
The EPDM/mPPE composite resulted in a breakage of the EPDM layer in adhesive strength tests. In order to analyze the interface, mPPE was dissolved in chloroform. It has been found that a crosslinking mPPE layer was formed in the interface by using attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy, and the crosslinking layer was built by DCP diffusing from EPDM into mPPE. Carbon radicals in the mixture of mPPE and DCP were detected by electron spin resonance (ESR) at the crosslinking temperature (180°C). On the other hand, the interfacial failure was occurred in EPDM/PA66 composite, because DCP diffusing into PA66 didn't efficiently affect radical generation in PA66: In the EPDM/POM composite, the interfacial failure occurred, because POM was not crosslinked by DCP diffusing into POM.抄録全体を表示PDF形式でダウンロード (4922K) -
宇川 仁太, 河原 成元2006 年 79 巻 12 号 p. 562-566
発行日: 2006/12/15
公開日: 2010/03/12
ジャーナル フリーCrosslinking point is one of important factors that govern mechanical properties of vulcanized elastomers. The method of how to characterize the crosslinking points through latex state 13C NMR spectroscopy was proposed for vulcanized NR instead of long standing solid state 13C NMR spectroscopy. Small signals at 44ppm and 58ppm in the aliphatic carbon region, which appeared after vulcanization, were assigned by Distortionless Enhancement by Polarization Transfer (DEPT) and Attached Proton Test (APT) to secondary, tertiary and quaternary carbons of crosslinking points, respectively. The latex state 13C NMR spectroscopy was proved to be indispensable to characterize the vulcanized NR.抄録全体を表示PDF形式でダウンロード (4020K) -
2. リビング重合杉山 賢次, 平尾 明2006 年 79 巻 12 号 p. 567-572
発行日: 2006/12/15
公開日: 2010/03/12
ジャーナル フリーThis paper reviews a general aspect of living polymerization. A living polymerization proceeds only in initiation step, followed by propagation step, but in the absence of the kinetic steps of termination and/or chain transfer. The propagating chain-end active center remains its activity after the completion of the polymerization. It is therefore possible to control the molecular weight by adjusting the feed ratio of monomer to initiator. The molecular weight distribution becomes narrow when the initiation is faster than the propagation in rate. The index value, Mw/Mn, reaches to near 1 according to the equation, Mw/Mn=1+1/DP (DP: Number average degree of polymerization). Using the living polymerization methodology, a variety of macromolecules with complex architectures is precisely synthesized. These polymers involve block and graft copolymers, chain-end-functionalized polymers, cyclic polymers, comb-like polymers, regular and asymmetric star-branched polymers, and various hyperbranched polymers with well-defined structures. Recently developed other mechanistic types of living polymerizations are also described including group transfer, cationic, radical, transition metal and rare earth metal-catalyzed, and ring-opening metathesis polymerizations.抄録全体を表示PDF形式でダウンロード (3059K) -
1. ケイ素化合物の反応とポリマー合成川上 雄資2006 年 79 巻 12 号 p. 573-577
発行日: 2006/12/15
公開日: 2010/03/12
ジャーナル フリーVarious reactions of silicon compounds are discussed briefly, according to the type of reaction, especially paying attention to stereochemical aspect of the reaction. Synthesis of polymers with well-controlled structure is described taking advantage of characteristic reactivity and stereochemistry of silicon compounds.抄録全体を表示PDF形式でダウンロード (2707K)
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