OP-II-3

OLIGOMERISATION OF TERTIARY AMINE LACTATESMulyashov S.A., Sirovski F.S., Beksaev S.G., Kolbakov V.V.Nordbiochem Ltd., Põlva, Estonia, sbeksaev@inbox.ruPP-III-46The amount of polymer waste in urban areas is growing at a threatening rate.Incineration of these wastes at municipal incinerating plants generates new riskssuch as dioxin and other ecotoxicant emission. Thus, biodegradable polymericmaterials with a short life cycle became lately the subject of interest. Polylactic acid(PLA) is the most promising of these polymers due to its properties and renewablefeedstock. All known methods of PLA manufacture include the microbial synthesis ofL-lactic acid as the first step. The next step is a polycondensation to oligomer.The removal of L-lactic acid from the culture fluid and its subsequent purificationpresents an important task. Three known methods exist: transfer into calcium lactate,esterification by C 1 -C 5 alcohols and as tertiary amine salt. The last method is themost advantageous as there are no solid wastes as in case of calcium and noevaporation of large volumes of water and product distillation is required as in case ofesters. Tertiary amines could be recovered and recycled back to the front end.Lactates of tertiary amines are able to undergo polycondensation affording theoligomer and free amine. It makes possible to use these lactates directly in PLAmanufacture.In this work we studied oligomerisation of trialkylammonium lactates attemperatures between 80 – 240 °C under vacuum. The reaction was monitored byHPLC with UV-detector and GC-MS. We identified several oligomers with n=1-4 andquantified them. The experimental composition of the reaction mixture was comparedwith theory data.The flowchart for the production of PLA oligomer using trioctyl amine wasdeveloped. The process mass balance and optimal performance parameters for thesynthesis of oligomer with molecular mass 1,500-2,000 DA were determined on theexisting pilot plant.523