We found that Acetohacter xylinum KU-l produced cellulose from D-mannitol. The optimum culture conditions for cellulose production were 1.5% D-mannitol, 0.5% Poly peptone, 2.0% yeast extract, pH 5, 30 o C, and 48 h. The amount of cellulose from D-mannitol was more than 3 times as much as that from D-glucose under the same culture conditions [productivity (mg/ml-medium): from D-mannitol, 4.6; from D-glucose, 1.2].

ABSTRACT:The polymerization of diphenylacetylene was investigated. The reaction was performed at 0-90°C in aromatic and halogenated hydrocarbons. The catalysts used are a mixture ofWCl 6 and tetraphenyltin (W catalyst) and a mixture ofMoCl 5 , ethanol, and triethylaluminum (Mo catalyst). Polymerization smoothly proceeded by the W catalyst to give yellow insoluble poly-(diphenylacetylene) in high yield. The Mo catalyst also provided poly(diphenylacetylene), which is dark red and insoluble. The IR spectroscopy, differential thermal analysis, and X-ray diffraction showed that the former polymer was rich in trans structure and amorphous, and the latter rich in cis structure and crystalline. The electric conductivity and paramagnetic property of the polymer are also described.

ABSTRACT:In order to elucidate the nature of the propagating species in cationic polymerization, isobutyl vinyl ether was polymerized by iodine in solvents of different polarities, both in the presence and absence of a common-ion salt (tetra-n-butylammonium tri-iodide). The molecular weight distribution (MWD) of polymers produced in salt-free methylene chloride at ooc was broad.With increasing salt concentration, the amount ofhigh-molecular-weight polymer decreased, and the MWD was very similar to that for the polymers produced in carbon tetrachloride. The polymerization rate was also reduced by the salt and approached a constant value. These results indicate the existence of two kinds of propagating species in different dissociation states in methylene chloride: dissociated and non-dissociated species. In spite of the existence of the two propagating species, however, the polymers did not show a bimodal MWD in methylene chloride. This, coupled with the uniformity in tacticity of the polymers, suggests a rapid exchange between the two species. In the cationic polymerization of styrene by acetyl perchlorate 1 • 2 or trifluoromethanesulfonic acid 3 • 4 and of p-methoxystyrene by iodine, 5 the produced polymers show a bimodal molecular weight distribution (MWD) in solvents of suitable polarity. The addition of common-ion salts to these polymerization systems suppresses the polymerization rate and the production of higher-molecular-weight polymers. We have interpreted these facts to be due to the coexistence of two kinds of propagating species in different dissociation states. counteranion as that of the propagating species may fulfill this requirement. However, there has been only one report concerning the common-ion effect on the cationic polymerization of vinyl ethers. Kunitake, et a/., 6 studied the steric structure ofpoly(isobutyl vinyl ether) formed by (C 6 H 5 ) 3 C+SnC1 5 -in the presence of the corresponding tetrabutylammonium salt; the steric structure was affected only slightly by the added salt.In the polymerization of vinyl ethers, on the other hand, the coexistence of such different species has not been shown yet, although the effect of solvent polarity on the steric structure and molecular weight of polymers suggests their presence. Since changing the solvent polarity is sometimes accompanied by complications such as selective solvation, it is desirable that the dissociation state of the propagating species be varied in the same solvent. Addition of a neutral salt (common-ion salt) having the same In the present study, we investigated the effects of both solvent polarity and common-ion salts on the polymerization of isobutyl vinyl ether (IBVE) to discuss the dissociation state of the propagating species derived from vinyl ethers. Iodine was used as an initiator which would give a highly nucleophilic counteranion that would interact strongly with a relatively stable propagating carbocation derived from IBVE. Our previous work 7 with styrene derivatives indicates that a combination of a nucleophilic cou...

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The relationship between dissipation factor at high frequency and polar group of epoxy resin was investigated.