This paper describes the synthesis and the biodegradation of optically active copolymers, poly[(R)-1-methyltrimethylene carbonate-co-ε-caprolactone] and poly[(S)-1-methyltrimethylene carbonate-co-ε-caprolactone] and poly[(R,R)-1,3-dimethyltrimethylene carbonate-co-ε-caprolactone] and poly[(S,S)-1,3-dimethyltrimethylene carbonate-co-ε-caprolactone]. The copolymers were prepared using a novel organolanthanide or AlEt3−H2O as the polymerization initiators, and their biodegradation by various enzymes and acclimated activated sludges was studied as a function of their composition, stereochemistry, crystallinity, T g (glass transition temperature), T m (melting point), molecular weight, and polydispersity. The copolymers synthesized exhibited high molecular weights with rather narrow molecular weight distributions and produced thermoplastic films when (R)-1-MTC (1-MTC = 1-methyltrimethylene carbonate) or (R,R)-1,3-DTC (1,3-DTC = 1,3-dimethyltrimethylene carbonate) content is less than 50 mol %. Optically active and racemic copolymers prepared using 1-MTC/CL (CL = ε-caprolactone) ratios of 17/83 to 19/81 were effectively biodegraded by lipoprotein lipase, cholesterol esterase and activated sludge. For the copolymers prepared using various 1,3-DTC/CL ratios, the poly(rac-1,3-DTC-co-CL) was biodegraded faster than the poly[(R,R)-1,3-DTC-co-CL] and poly[(S,S)-1,3-DTC-co-CL] copolymers regardless of the 1,3-DTC/CL ratio. Biodegradation of all of these copolymers generated numerous cavities on the outermost surface of polymer films or solid masses without changing their molecular weight and polydispersity.

Polyglycolide is the simplest aliphatic polyester. Patents say that fibers and films with a high melting point and high strength can be made from this polymer 13). Recently, some of its properties were rep~rtedq,~), but polymerization behavior and detailed polymer property, especially its stability, have been obscure as yet.The ring-opening polymerization of glycolide and the property of polyglycolide have been studied in detail. The tensile yield strength of the stabilized sheet made from glycolide-lactide copolymer was about 17,000 psi, the value being larger than those of all commercial plastics. In this paper, the results of the ring-opening polymerization of glycolide are presented. ' The glycolide was prepared through the elimination of sodium chloride from sodium monochloroacetate. The monomer was purified by recrystallization to obtain a melting point above 83°C. The process we have studied is as follows. A. HomopolymerizationBulk polymerization with various catalysts was carried out in a sealed ampule under reduced pressure. The adequate polymerization condition was to heat a t 17OoC. for 10 hrs., or to heat a t 17OoC. for 2 hrs., then a t 230°C. for 0.5 hrs.Anionic polymerization catalysts such as potassium hydroxide, pyridine, and potassium carbonate gave brittle and highly colored polymers in low yield.Polymers were also prepared by using protonic acids such as sulfuric acid and phosphoric acid to yield brittle and highly colored polymers in high yield. 262

Nutritional enrichment for rotifer is necessary for the stable production in larviculture. Although manufacturers recommend feeding amount for enrichment diets, the effects of these recommended amounts on nutritional enrichment of rotifer are unknown. We assessed the effects of normal and overdose amount of enrichment diets on nutritional enrichment of rotifer using batch and continuous culture methods. Rotifer populations in two culture systems were enriched using four enrichment conditions, matched two diet levels, and two enrichment durations: 0.25 g/L for 8 h (normal enrichment) 0.25 g/L for 24 h (longer enrichment), 0.75 g/L for 8 h (overdose enrichment), and 0.75 g/L for 24 h (overdose + longer enrichment). When the batch-cultured rotifer populations were enriched, longer and overdose enrichments could not make the fatty acid contents differ from the normal one. Overdose enrichment was most effective of all enrichment conditions when continuouscultured rotifer populations were used. In both culture methods, the docosahexaenoic acid (DHA) content under overdose + longer enrichment conditions was two to three times as high as normal enrichment conditions and it resulted in two-to threefold increase in DHA/eicosapentaenoic acid ratio by overdose + longer enrichment. Accordingly, it is possible to alter the fatty acid composition of rotifer by changing the enrichment method.

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SUMMARY: Oligomerization of e-caprolactone and d-valerolactone was performed by use of SmMe-(C 5 Me 5 ) 2 (THF) 2 initiator, and the 26-mer, 28-mer and 30-mer of e-caprolactone were isolated in pure form by preparative SFC. The MALDI-TOF mass spectrum of the 28-mer indicates that the parent peak (3 256.1) emerges as 28-mer + 2Na -H (3 256.9). The ESI mass spectrum of the 28-mer indicates that the molecular weight (3 211.7) is consistent with the calculated value (3 211.9). In a similar manner, the 19-, 25-and 32-mers of d-valerolactone were isolated. The MALDI-TOF mass spectrum of the 19-mer indicates that the parent peaks (1 896.6 and 1 879.9) emerge as 19-mer + Na + K + MeOH -1-hexanol-5-one (1 896.3) and 19-mer + 2Na + MeOH -1-hexanol-5-one (1 880.2). Glass transition and melting temperatures (T g and T m ) of oligo-e-caprolactones and oligo-d-valerolactones increase with increasing degree of polymerization.