Emulsion polymerization of viny lacetate in the presence of certain of biodegradable aliphatic polyester (APE) and trace amounts of poly (vinylalcohol) brought about a novel emulsion system of an interpenetrating type of hybrid polymer.An excellent film could be prepared from this APE-poly (vinylacetate) (PVAc) hybrid emulsion even at 0℃.According to JIS K6950, biodegradability of the film was evaluated by monitoring of biochemical oxygen demand (BOD) with an activated sludge.In contrast with a film prepared from a conventional PVAc-based emulsion, BOD/TOD value for the hybrid film attained to about 60% after 45 days.By measurement of gel permeation chromatography and NMR for extracts by DMSO after degradation test, it can be found that a pendant ester group of PVAc was completed to cleave bio-chemically and APE was remarkably shorten.In the test as an adhesive, the hybrid emulsion showed a satisfactory performance except for the humidity-resisting property.

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4-Vinylpyridine-jV-isopropylacrylamide(4VP-NIPAAm)copolymerswerepreparedbyradicalcopolymerization.The4VP-NIPAAmcopolymerswerereactedwithvariousalkyliodides(CH:)I,CtHgl,C8HitI)andthecopolymei､(4VPNR-NIPAAm)containingpyridiniumgroupshavingmethyl,butyloroctylgroupsworeobtained.Thequarternizedratiowasaffectedbythereactiontimeandthetemperature.The4VPNR-NIPAAmcopolymersobtainedhadthermosensitivityornothermosensitivitydependingonthedegreeofquarternizationofpyridinegroupsandchainlengthofalkylgroupsintroducedintopyridiniumgroups.Thetemperaturedcpcndenceofthetransmittanceof4VPNR-NIPAAmcopolymersolutionsat660nmincreasedwithincreasingNaClconcentrationofthesolutions.ThesecopolymershadhighflocculationabilityagainstbacteriasuspensionssuchasE.coliandtheabilitywasaffectedbythedegreeofquarternizationofpyridinegroupsandchainlengthofalkylgroupsintroducedintopyridiniumgroups.Theyalsohadantibacterialactivityagainstbacteria

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