Structure of Bacterial Cellulose-Brightener Complex from Aspect of Behavior of Its MercerizationKai, Akira; Xu, Ping
doi: 10.1295/polymj.22.955pmid: N/A
The structure of the cellulose-brightener complex obtained from the Acetobacter-culture in the presence of a fluorescent brightener was examined from the aspect of mercerization. The cellulose from the culture with the brightener showed characteristic X-ray diffraction indicating the formation of the crystalline complex with the brightener, regardless of the strain cell and brightener concentration of the medium. The brightener content in the complex from the incubated medium with it of below 0.05 wt% increased with its concentration. In the case of more than 0.05 wt%, the sites of the complex being able to dye were saturated by the brightener. The resistance toward alkali of the never-dried complex decreased with decreasing brightener content, and that of the complex from the incubated medium with the brightener of about 0.005 wt% became minimum. The resistance toward alkali of the dried complex including the brightener of 0.059 mol mol−1 of glucose residue, became higher than that of the never-dried sample. In contrast, that of the dried complex including the brightener of 0.095 mol, became lower than that of the never-dried sample.
Preparation of Styrene Derivatives Containing Sulfide Group: Kinetic Studies on The Addition Reaction of Thiophenol to 1,4-DivinylbenzeneJiang, Jian; Kobayashi, Eiichi; Obata, Takatsugu; Furukawa, Junji
doi: 10.1295/polymj.22.963pmid: N/A
The addition reaction of thiophenol to 1,4-divinylbenzene affords mono-adduct, 4-vinyl-1-[(2-phenylthio)ethyl]benzene with about 70%, and di-adduct, 1,4-bis[(2-phenylthio)-ethyl]benzene. Reaction rate dependence on the reagent concentration was studied by gas chromatography. The reaction rate depends on the first order of the thiophenol concentration and one half order of AIBN concentration. The addition reaction proceeds by a radical chain mechanism and the rate determining step is thought to be the hydrogen abstraction from thiophenol by the intermediate carbon radical. The ratio of the overall reaction rate constants of the first addition (k
1) and second addition (k
2) to the two vinyl groups of 1,4-divinylbenzene, k
2/k
1 was estimated using a computer curve fitting method in comparison with the experimental data. The values of k
2/k
1 are in the range of 0.18 to 0.25 at 60°C and 75°C, respectively. The reaction rate constant of the second addition is one fourth to one sixth that of the first addition. High reaction temperature is a disadvantage to obtain much higher yields of the mono-adduct.
Comb-Like Copolymers Obtained by Copolymerization of 2-Amino-4-(N-alkylanilino)-6-isopropenyl-1,3,5-triazinesKunisada, Hideo; Yuki, Yasuo; Kondo, Shuji; Miyatake, Jun; Maeda, Chieko
doi: 10.1295/polymj.22.977pmid: N/A
Copolymerizations of 2-amino-4-(N-alkylanilino)-6-isopropenyl-1,3,5-triazines with styrene, methyl methacrylate and methyl acrylate were carried out using azobisisobutyronitrile as an initiator. Alkyl groups were propyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, and docosyl. Copolymerization parameters (r
1, r
2, Q, and e) were determined for these monomers. No significant effect of alkyl chain length on the copolymrization parameters could be observed. Relationships between glass transition temperatures and composition of the copolymers were investigated. Crystallization exothermic and melting endothermic peaks due to the side-chains were observed in the DSC thermograms of the comb-like copolymers containing octadecyl and docosyl groups. The crystallinity of the side-chains decreased with increasing content of styrene or methyl methacrylate in the copolymers.
Effect of Tetra-Alkyl Ammonium Bromide on the Rheological and Thermal Properties of Kappa-Carrageenan and Agarose GelsWatase, Mineo; Nishinari, Katsuyoshi; Williams, Peter A; Phillips, Glyn O
doi: 10.1295/polymj.22.991pmid: N/A
Dynamic viscoelastic measurements and differential scanning calorimetry were carried out for kappa-carrageenan gels containing tetra-alkyl ammonium bromide in order to clarify the structure and functional properties of kappa-carrageenan. The dynamic Young’s modulus E′ of the gels showed a maximum as a function of concentration of tetra-alkyl ammonium bromide at around 0.2 mol l−1. At any particular temperature E
max′ decreased in the following order: E
max′(Me4N-)>E
max′(Et4N-)>E
max′(Pr4N-)>E
max′(Bu4N-). The temperatures Tm of the endothermic peak accompanying the transition from gel to sol in the heating DSC curves shifted to higher temperatures with increasing salt concentration. The order of the melting temperature of these gels was the same as in E
max′, however, the enthalpy of melting showed the reverse order. Cations with smaller dynamic hydration number n
DHN increase the elastic modulus and the melting temperature of kappa-carrageenan gels more than those with larger n
DHN.
Electronic Structure of PolyazuleneTanaka, Kazuyoshi; Toriumi, Michio; Wang, Shenglong; Yamabe, Tokio
doi: 10.1295/polymj.22.1001pmid: N/A
Electronic structure of polyazulene (PAz) has been studied based on its optimized structure of the neutral state using the one-dimensional tight-binding SCF-CO (self consistent field-crystal orbital) method. The oxidized states of polaron and bipolaron natures were also examined. It is found that the positive net charges of the oxidized states are mainly localized in the seven-membered ring and that in the polaron state the charge and the spin parts are separated in an azulene ring. It has been conjectured that confinement of the π hole in the seven-membered ring inherent in PAz is unfavourable for the intrachain electrical conduction.
Oligomerization and Copolymerization of endo-N-Cyclohexyl-9-oxabicyclo[2,2,1]hept-2-ene-5,6-dicarboximideOishi, Tsutomu; Momoi, Masaaki; Fujimoto, Minoru
doi: 10.1295/polymj.22.1007pmid: N/A
endo-N-Cyclohexyl-9-oxabicyclo[2,2,1]hept-2-ene-5,6-dicarboximide (CHO or endo-CHO), one of the norbornene derivatives, was prepared from N-cyclohexylmaleimide (CHMI) and furan (FN) according to the Diels-Alder reaction. The number average molecular weights (M̅
n) of the polymers insoluble in methanol were 1100 to 2000, i.e., the degree of polymerization was 4 to 8. The oligomers having M̅
n below 1000 were soluble in methanol. Retro-Diels Alder reaction mainly took place in the bulk reaction of CHO over 140°C. CHO was copolymerized with styrene, methyl methacrylate and vinyl acetate in the presence of radical initiators. The monomer reactivity ratios and Alfrey-Price Q-e values were determined.
Synthesis and Characterization of Polyamide by Interfacial Polycondensation of Dichloroformyl-Containing γ-Lactone with HexamethylenediamineKimura, Takao; Morimoto, Hideo; Sasaki, Eiji; Tanji, Kazunobu; Hamashima, Motome
doi: 10.1295/polymj.22.1015pmid: N/A
(2R
*,4S
*)-4-chloroformyl-2-chloroformylmethyl-2,4-dimethyl-4-butanolide was prepared by the chemical transformation of t-butyl methacrylate dimer telomerized using bromotrichloromethane. The interfacial polycondensation of this acid dichloride with hexamethylenediamine was accompanined by a partial hydrolytic cleavage of the lactone ring and gave an unique 6,6-type polyamide containing both lactone rings and hydrophilic groups such as carboxyl- and hydroxyl-groups. To determine the optimal conditions for interfacial polycondensation, the influence of the following factors on yield, value of intrinsic viscosity, and ring-opening ratio of polyamide was studied: volume of phase solvent, molar ratio of diamine to acid dichloride, molar ratio of sodium hydroxide as a hydrogen chloride acceptor to acid dichloride, temperature of reaction, the kinds of hydrogen chloride acceptors and organic phases, and contribution of stirring. The resulting polyamide was highly soluble in methanol, which is a poor solvent for conventional polyamides. A transparent and flexible film prepared from the methanol solution by a casting technique had a glass transition temperature of 88°C and a water absorption of ca. 30% at 95% relative humidity. Furthermore, the carboxylato-containing polyamide modified by treatment with potassium hydroxide was very soluble in water.