In order to prepare a polystyrene macromer composed of only hydrocarbon, (p-vinylbenzyl)polystyrene macromer, the direct coupling reaction of polystyryllithium with an excess of p-vinylbenzyl chloride was carried out under various reaction conditions. The effect of solvent on the reaction was pronounced.When a solution of PSt-Li in a mixed solvent of benzene and THF (THF, ca. 20 vol %) was added dropwise to a solution of p-vinylbenzyl chloride in THF at 0 °C, the yield of the macromer was approximately 100% whereas when a smaller amount of THF was present in a polystyryllithium solution, the dimeric-terminated polystyryllithium formed to some extent as a byproduct. The characterization of the macromer obtained showed it to have one p-vinylbenzyl group per (p-vinylbenzyl)polystyrene molecule and an "/ of 1.05.

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Monodisperse and pure macromers were synthesized by means of living polymers of cationic and anionic polymerizations. The macromers obtained were polytetrahydrofuran-, polystyrene-, polyisoprene-, andpoly(2-viny1pyridine)-macromers. The radical homopolymerizations of these macromers were performed, and the high reactivity of the macromers was revealed. copolymerizations of macromers with common small monomers were performed and rL and rz values were estimated. copolymerizations between two kinds of macromers were carried out to prepare a unique double-colored multibranch-polymer.

Styrene-terminated poly(2-vinylpyridine) macromers, i.e., a-(p-vinylbenzyl)-and a,o>-bis(pvinylbenzyl)poly(2-vinylpyridines), were prepared by reaction of -lithioand a,w-dilithiopoly(2-vinylpyridines) with p-vinylbenzyl chloride, respectively. In this reaction, the -pyridyl carbanion does not attack the vinyl group of p-vinylbenzyl chloride but exclusively reacts with its chloromethyl group. This selectivity leads to macromers with very high functionality (>96%) even in the case of the preparation of a,w-bis(p-vinylbenzyl)poly(2-vinylpyridine). A method for determining the functionality of the macromers was employed that involves copolymerization with methyl methacrylate followed by GPC analysis. The values determined by the method were confirmed by NMR spectroscopy and radical homopolymerization.

The occurrence and characterization of toxigenic vibrios in surface water and sediment samples of the fresh water environment of the Ohta River were studied. The membrane filter, pad preenrichment technique, followed by the placement of membranes onto thiosulfate citrate-bile salt-sucrose agar, was used for the enumeration of total vibrios. Qualitative examination of pathogenic vibrios was also attempted. In addition, a survey was conducted to determine the incidence of Clostridium botulinum in sediment samples of the Ohta River and the Hiroshima coast. In the identification of 361 strains, 12 species of Vibrio and two species of Listonella were observed. Non-Ol Vibrio chokrae was prevalent among the members of the genus Vibrio. Vibrio parahaemolyticus (serotype 04:K34), isolated in fresh water, is significant and suggests that some still unknown conditions promote the survival of these organisms in fresh water. An estimated 132 strains were hemolytic by a simple agar method, and further characterization revealed that 82% of the hemolytic vibrios (107 strains) produced various toxins. About 71% (93 strains) elaborated cytotoxin, 55% (72 strains) produced hemolysin, and 44% (58 strains) responded for both cytotoxin and hemolysin in the crude toxin extracts. All the non-Ol V. cholerae showed cytotoxic activity, and the virulent strains of Vibrio fluvialis and Vibrio spp. showed cytotonic responses in RK-13 cells. Of 36 sediment samples tested, 10 harbored C. botulinum spores (28%) and were isolated invariably in all the regions of the Hiroshima coast and in the Ohta River, except the upper region of the Ohta River.