Jerzy WISIALSKI, Joanna SIRAK, Ludwik SYNORADZKI, Paweł RUŚKOWSKI ?Laboratory of Technological Processes, Faculty of Chemistry, Warsaw University of Technology, Warsaw

Please cite as: CHEMIK 2013, 67, 3, 220-222

Polylactide (PLA) is a biodegradable aliphatic polyester. In order to develop the manufacturing technology of biodegradable polyesters (including PLA), a consortium of three institutions was established: Centre of Molecular and Macromolecular Studies in Łódź, Institute of Biopolymers and Chemical Fibres in Łódź and Faculty of Chemistry of Warsaw University of Technology. As the part of the Faculty of Chemistry of the Warsaw University of Technology (WUT), the Department of Chemistry and Polymer Technology, as well as the Laboratory of Technological Processes (LPT) participated in the project ? they were responsible for the project and construction of the model research installation for synthesis of PLA. The LPT specialises in a complex technology development, process and technological installation designing, scaling up processes and experimental manufacturing in Half-Techniques Halls, all of which are also utilised in teaching.

Poly-L-lactide product flow derives from carbohydrates in raw materials (e.g. corn starch) from which, following fermentation, lactic acid is obtained and then L-lactide is derived by polycondensation and depolymerization. The research subject-matter under the project is the synthesis of Poly-L-lactide by ROP (Ring Opening Polymerisation) reaction:

Tin (II) octanoate is a typical catalyst used in ROP. Its manufacturing technology was developed and implemented in the LPT. The polymerisation process of lactide is classified as the so-called Bulk Polymerisation. Optimisation studies of the PLA synthesis were carried out in a laboratory scale: glass ampoule, 100 and 1000 ml reactors, as well as 4×50 ml reactors with IR probe which enables tracking reaction progress in situ.

One of the tasks of the LPT was to design and construct the model research installation for the PLA manufacturing. Technological assumptions were formulated for process scaling up. V=2 l polymerisation reactor unit, equipped with monomer melter, was designed and constructed. The concept of V=10 l reactor unit to carry out the process, both periodic and continuous, and the concept of 2-stage process (polymer ? polymer) with the use of reactive extruder, were developed. Exemplary variants of carrying out the process:

Periodic 1-stage process in the V=10 l tank reactor, direct loading of lactide into the reactor or with the melter and a pump, extrusion with an extrusion pomp or compressed nitrogen
? Periodic 2-stage process in the V= 10 l (pre-polymer) reactor and finish reacting in a reactive extruder
? Continuous 1-stage process in the reactive extruder (system of modules and screw elements was configured)
? Continuous 1-stage process in the V=10 l flow tank reactor, powered by melted monomer and a catalyst dosed by the pomp through static mixer, polymer excursion by the
extrusion pomp
? Continuous 2-stage process with the use of V=10 l flow tank reactor, as in the 1-stage process, and pumping over the melted pre-polymer into the reactive extruder.

A complex research installation project was designed. Detailed construction assumptions for the equipment and computer system of process control were formulated. As a result, the model research installation was constructed, its main units being:
? V=10 l Polymerisation reactor unit (Fourné Polymertechnik)
? D=2x25mm L/D=48 Twin screw reactive extruder unit (KM Berstroff)
? V=2 l Test reactor unit (Austenit Sztajerwald)
? Water trough, belt for cooling polymers with air, cutter
? Energy utilities and auxiliary installations
? Supervisory control and data acquisition (SCADA)
The flexible configuration of the installation enables carrying out tests of synthesis process, of both PLA and other polymers, in different technological variants.

Jerzy WISIALSKI ? Ph.D., (Eng.), is a Deputy Head of the Laboratory of Technological Processes of the Faculty of Chemistry at the Warsaw University of Technology. He is a graduate of the Faculty, from which he obtained his Master of Science degree in Chemical Engineering (in 1970), and a Doctoral degree in the field of chemical engineering (in 2010). Professional career: Internship at RefineryPetrochemical Plant in Płock (1971). Between , Design Engineer in ?Organika? design office in Warsaw, the author of numerous chemical installation designs. Since 1989, an expert at SITPChemNOT Association in the field of chemical plant design. Between , cooperation with an international consortium to develop installation project and technology for industrial manufacturing of natural benzaldehyde (which later was his doctoral dissertation topic). The installation construction supervising and bringing it into use in Italy (in cooperation with a Scottish engineering company) and industrial test of the production plant technological process. Since 1993 a Chief Technologist, and since 2003 ? Deputy Head of Laboratory of Technological Processes (LPT) of the Faculty of Chemistry at Warsaw Institute of Technology. Participating in many development and research projects. The author of many research and half-technical installation projects Participating in numerous patents and know-how. Cooperation in teaching technological design at the Faculty of Chemistry at WUT and publications in this field. Gold Cross of Merit (2002). Since 2010 participating in the POIG research project ?Technology for obtaining biodegradable polyesters using renewable raw materials? (BIOPOL). Main areas of interest: processes and technological installation designing, complex development and implementation of new technologies, development and investment projects, chemical and process engineering.
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Joanna SIRAK ? M.Sc., graduated from the Faculty of Chemical and Process Engineering at the Warsaw University of Technology in 2010, major: Chemical Engineering. She is currently working as a process engineer in the Laboratory of Technological Processes at the Faculty of Chemistry at the Warsaw University of Technology. She is involved in the realisation of the POIG (Innovative Economy Operational Programme) research project ?Technology for obtaining biodegradable polyesters using renewable raw materials? (BIOPOL). Research interests: designing pilot plant installations
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Ludwik SYNORADZKI ? (Sc.D., Eng), Associate Professor , graduated from the Faculty of Chemistry at the Warsaw University of Technology in 1971. Since 1985 he has been working as a Head of the Laboratory of Technological Processes at the same Faculty. Specialisation: chemical technology. He is a head and a contractor in many research and development projects. He is a co-creator of teaching technological designing at the Faculty of Chemistry of the Warsaw University of Technology. He is the author and co-author of numerous publications, patents, know-how and lectures at science conferences. He was honoured with Gold Cross of Merit in 2001. He has been involved in the realisation of the POIG (Innovative Economy Operational Programme) research project ?Technology for obtaining biodegradable polyesters using renewable raw materials? (BIOPOL) since 2010. Research interests: designing and implementing technological processes, chemistry and technology of tartaric acid derivatives.
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Paweł RUSKOWSKI ? Ph.D., (Eng), is Assistant Professor in the Laboratory of Technological Processes of the Faculty of Chemistry at the Warsaw University of Technology. He graduated from the Faculty of Chemistry at the Warsaw University of Technology in 1998, and defended his doctoral thesis at the same Faculty in 2009. He is co-author of 3 technology implementations at an industrial scale, 3 articles and many lectures at science conferences. He has been involved in the realisation of the POIG (Innovative Economy Operational Programme) research project ?Technology for obtaining biodegradable polyesters using renewable raw materials? (BIOPOL) since 2010. Research interests: chiral derivatives of dicarboxylic acids, biodegradable acyclic polyesters, optimisation of process parameters, expanding scale.
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