Biodegradation and valorization pathways for petroleum-based plastics and polymers

Transcription

1 Biodegradation and valorization pathways for petroleum-based plastics and polymers Nadia Lotti University of Bologna - DICAM nadia.lotti@unibo.it and Fisheries and Biotechnology theme for the 7 Framework Programme

2 Introduction Identification and selection of microorganisms and enzymes capable of degrading petroleum-based plastic wastes (polyolefines, polystyrene, polyvinyl chloride) I. Evaluation of the polymers and plastics biodegradation rate and mechanism by the most promising microbial cultures and enzymes; II. Identification of the boundary conditions governing the depolymerization activity of the microorganisms and enzymes; III. Identification of the main degradation products and their valorization

3 Evaluation of plastic biodegradation rate and mechanism Lab scale experiments to find out extents, rates and major mechanism involved in aerobic and anaerobic degradation of recalcitrant polymers by the most promising bacteria (aerobic and anaerobic), fungi and enzymes already selected by preliminary screening Evaluation of biodegradation rate Characterization of partially degraded polymeric materials Analysis of the degradation products

4 Evaluation of plastic biodegradation rate and mechanism Evaluation of biodegradation rate weight loss measurements CPC, SEC, MALDI-TOF-MS: molecular weight variations and molecular weight distribution Characterization of partially degraded polymeric materials NMR and FT-IR: appearance of functional groups SEM: analysis of the polymeric surface Analysis of the thermal and mechanical properties before and after degradation

5 Evaluation of plastic biodegradation rate and mechanism Analysis of the degradation products Synthesis of 14C-labelled polymers Fractionation and enrichment of the degradation products by means of different chromatographic tecniques Ecotoxycological analysis Biological toxicity tests Genetic toxicity tests molecular taxonomic characterization via total DNA extraction, PCR amplification of obtained DNA and DGGE analysis of fragments obtained of the most promosing cultures

6 Identification of the boundary conditions Liquid cultures and solid-state fermentation studies will be performed under different experimentsl conditions such as: ph, temperature, aeration, nutrient, etc. optimal design of biodegradation and enzymatic processes and bioaugmentation protocols for the different polymers will be drawn development of biotechnological processes for plastic degradation and of bioaugmentation strategies to enhance plastic biodegradation under field conditions

7 Exploitation of degradation products Identification of the possible routes for using/reusing oligomers and degradation products obtained from enzymatic depolymerisation/transformation of the polymers under study Possible applications will be evaluated depending on the kind and number of terminal functional groups building blocks to produce new eco-friendly polymers with improved biodegradability additives for asphalt binder performance (waxes) plasticizers or surfactants macroinitiatiors for ROP of lactones

8 New eco-friendly polymers from plastic degradation products the enzymatic hydrolytic conditions or combination of enzymes able to provide the searched, more suitable/reactive oligomers will be analyzed process conditions able to provide a tailored polymerization of oligomers will be searched and the preparation of new (hybrid) block copolymers as well as multifunctional brushes or star polymers will be investigated different synthetic strategies will be adopted (macromonomers, macroinitiator, reactive blending or polycondensation) depending on the terminal functional groups polymerization process will be optimized, varying reaction temperature, time and kind of catalyst the polymers obtained will be subjected to molecular and solid-state characterization to check the final material properties and correlate them with chemical structure

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