Day 2 :
Lackner Ventures & Consulting GmbH, Austria
Dr. Maximilian Lackner earned his PhD in 2003 and his habilitation in 2009 from Vienna University of Technology. He has held several senior leadership positions in the polymer industry in Austria and China. Dr. Lackner has founded 5 companies, amongst them one for antimicrobial polymers and one in the area of bioplastics, Lackner Ventures & Consulting GmbH. This company collaborates with JinHui Zhaolong, one of the largest PBAT manufacturers. The research interests of Dr. Lackner include PHA and PBAT. Lackner Ventures & Consulting GmbH runs a research project to produce PHB from CO2 and sunlight using cyanobacteria. Dr. Lackner has authored more than 100 scientific articles. He teaches materials science at the University of Applied Sciences FH Technikum Wien.
The use of conventional plastics has become a huge environmental concern. is a growing concern, leading to resource depletion and littering (e.g. microplastics pollution of the sea). Polyhydroxybutyrate (PHB) is formed as energy storage compound by several microorganisms. It has thermoplastic properties and can be a replacement for PP. PHB is fully degradable, also in the marine environment. Today, PHB is synthesized by heterotrophic bacteria using sugar fermentation. The relatively high costs of raw materials and continuous oxygen supply for the processing make PHAs expensive in comparison to other petroleum-derived plastics. Methodology and theory: The alternative is to use certain oxygenic cyanobacteria as cell factory. Cyanobacteria can store PHB under nutrient (P, N) limitation from renewable and sustainable resources sunlight and CO2 and due to their minimal nutrient requirement are the most promising host system for PHB production. However the growth rate and the PHB yield stay low. There exists no general method to increase PHB yield in cyanobacteria. This work aims at making cyanobacteria competitive by optimization of growth conditions and by strain selection. Findings: We screen for wild type strains which can naturally accumulate PHB. During our systematic screening we have discovered a cyanobacterium sp. strain which naturally accumulates a high PHB content under N and P limitations in comparison to other existing strains. The improvement of the strain is possible using process engineering and natural mutations. Significance: Our project can develop an economically superior bioprocess to enhance biomass growth and PHB productivity and prove feasibility to use CO2 for production of biodegradable plastics.
National institute of chemistry, Slovenia
Matjaž Kunaver has done his MSc from the University of Leeds UK in 1991 and has received his PhD degree in 1998 at the University of Leeds, UK. He is a Senior Scientist Researcher at the National Institute of Chemistry, Laboratory for Polymer Chemistry and Technology, Ljubljana, Slovenia and is an Assistant Professor at the University of Ljubljana and Polymer Technology College. His main fields of research are the utilization of biomass as a feedstock for polymer synthesis and production of nanocellulose. He has published more than 50 original scientific papers and 6 patents.
Cellulose containing Biomass represents an immense and renewable source for the production of bio-fuels and valuable chemicals. A little amount of this is used in industry and the remaining is leftover in huge quantities. Much effort has been devoted to converting these types of biomass into useful industrial and commercially viable products. In recent years, some effective processes have been found, such as thermochemical conversion producing several new products from these renewable resources. An overview of such applications and methods will be presented in this contribution. One of possibilities of converting biomass is the liquefaction[i]. During liquefaction reaction, lignocellulosic components are depolymerised to low molecular mass compounds with high reactivity, high hydroxyl group content and can be used in many useful applications. A high energy ultrasound or microwaves can be used as an energy source to speed up the liquefaction process. The liquefied biomass was used as a feedstock in the synthesis of polyesters, polyurethane foams and adhesives. The same liquefaction process was used for the isolation of the nanocrystalline cellulose from biomass. The method is a novelty and a
model procedure for NCC isolation from different natural cellulosic sources with high yields and with high crystallinity index[i].
The process of preparing NCC from different natural sources uses glycols as the main reactant and an acid catalyst in low concentration (only 3%). Here, during the one step reaction, lignin, hemicelluloses and the more disordered components of the cellulosic fibers are liquefied, only the crystalline cellulose remaining as a solid residue.
The liquefaction reaction, using glycols and mild acid catalysis, was optimized and applied to four model materials, namely cotton linters, spruce wood, eucalyptus wood and Chinese switch grass. The % recovery of the nanocrystalline cellulose, the crystallinity index of the nanocrystalline cellulose and the average crystal dimensions are presented in the Table 1. The main benefit of the process arises from the ability to prepare stable NCC suspensions in an organic medium at 10 times greater loadings than can be achieved in aqueous suspensions. The liquid residues contain significant quantities of levulinic acid and different sugars that were derived from cellulose and hemicelluloses.
- Session 1
SILAB, Brive, France
Michel Dana defended its PhD in organic chemistry at the University of Bordeaux I in 1996. Michel works at SILAB since 1997 and is now manager of the new technology platform
Interpenetrating polymer networks (IPN) (1) have gained great attention in the last decades, mainly due to their biomedical applications. IPN present properties that can be very different according to the macromolecular constituents and that can be tailored by the process. Currently, IPN are composed of chemical polymers or cross-linked by using chemicals. Our study aimed to develop an IPN based on natural polymers and chemical free to obtain a biopolymer-based film with “second skin” (2) properties, biosourced, biodegradable and in accordance with the requirements of the cosmetic industry.
For this purpose, we studied the influence of different natural polysaccharides molecular mass and their ratio but also the natures and concentration of the cross linker on the IPN properties, in the manufacturing process. This approach led to the development of the eco-designed and patented IBPN technology® (Interpenetrating BioPolymer Network). The resulting material is composed of a galactomannans network from Caesalpinia spinosa (3, 4) and of a sulfated galactans network from Kappaphycus alvarezii (5, 6) ionically crosslinked. Thermodynamic analyses by DSC (Differential Scanning Calorimetry) and DMA (Dynamic Mechanical Analyses) associated with visualization by AFM (Atomic Force Microscopy) and SEM (Scanning Electronic Microscopy) revealed the physical-IPN organization of the obtained material. Applied to the skin, this natural physical-IPN forms a “second-skin” film since it protects against mechanical aggressions (-14%, P<0.05), pollutants (-47%, P<0.001) and irritants (-22%).
In conclusion, the resulting biopolymer-based film has outstanding “second skin” properties. It is biodegradable and perfectly suitable to the cosmetic industry requirements. The sourcing of the two plants used for its production is sustainable. This study demonstrates the interest of the interpenetrating biopolymer network technology for new promising applications
Martin Alberto MASUELLI is Master of Surfaces Science and Porous Media (2003), and Doctor in Chemistry (2007), title obtained in National University of San Luis, Argentina. Member of the Institute of Applied Physics (INFAP) belonging to National Council for Scientific and Technical Research (CONICET), as Research Assistant, 2011. He won three scholarships. He is UNSL Adj. Professor. He is the director of Director of the Laboratory of Physical Chemistry Services, UNSL. He has published more than 19 papers in journals and has been serving as a reviewer and editorial board member of repute, 5 book chapters and 52 congress presentation. Guest Editor of the Books: "Fiber Reinforced Polymers-The Applied Technology for Concrete Repair," INTECH, Croatia, 2013; "Advances in Physicochemical Properties of Biopolymers”, Bentham Publishing, USA, April 2016; "Biopackaging", CRC Press, April 2017. Editor in Chief and founder of the Journal of Polymer Physics and Chemistry Biopolymers, July 2013. He is also a member of the Argentina Association of Physicochemical and Inorganic Chemistry (AAFQI), and Argentina Society of Environmental Science and Technology (SACyTA). Recognition of Excellence in the review of papers in 2012, Desalination, Elsevier. Director of Project PRO 2-2414, UNSL: "Regional polysaccharides: Purification and Physical Chemistry Characterization. Applications: Analytics, a Separative Processes and Food Industry”, 2014.
Cucurbita ficifolia is a creeping plant with a fleshy fruit, round and elongated, with a thick, smooth shell, resistant to low temperatures but not to severe frost (Figure 1). The mesocarp (pulp) is white with a granular and fibrous texture. The fruit was separated into three parts: peel, pulp and seeds. The pulp was dried and then ground to obtain the flour from which the hydrolysis was carried out.
Figure 1: Some cucurbits. to. Cucurbita maximum (pumpkin). B. Cucumis melo (yellow melon). C. Citrullus lanatus (watermelon). D. Cucumis sativus (cucumber). and. Cucurbita ficifolia (alcayota). F. Cucurbita moschata (zapallo anco).
Hot aqueous extracts were made to the moist pulp and a Cy (d) dispersed (used for rheology) solution Cy (d) solution (used for capillary viscosimetry) was obtained.
From Cy concentrations of 0.1%, 0.2%, 0.4% and 0.6% wt. in an aqueous solution of 0.1M NaCl, which acts as a stabilizer, the intrinsic viscosity was measured with an Ubbelodhe 1B viscometer and density with Anton Paar DM35N densimeter in the thermostatic bath at 25°C.
The hydrolysis procedure was performed on the Cy (d) dispersion, with 0.1M NaOH at 65°C for two hours and then precipitated with ethanol. The precipitate is washed with ethanol several times, obtaining a polysaccharide of average molecular weight having free oxydril groups called CyOH (d). To the above dispersion (CyOH (d)) was added 5 ml of glycerol and stirred cold for a few minutes to homogenize, these solutions were used to measure the flow ability curve. Also, dispersions of Cy (d) of different concentrations: 2, 3, 4, 5, and 6% in distilled water were prepared. Some of them were hydrolyzed, being named as CyOH (d) and measured with a Brookfield DVIII rheometer at a temperature of 25°C. The assay was repeated by adding 2, 4 and 5% glycerol to some of the hydrolyzed dispersions at temperatures of 35 and 40°C in a thermostatic bath.
The intrinsic viscosity was 149.83 cm3/g and the molecular weight was 1867000 g/mol (Marck-Houwink parameters of k = 0.00263 and a= 0.7583), with a hydrodynamic radius of 53nm, a shape factor of 3.12 and a hydration value of 47.63 g/g. Studies for CyOH (d) showed a thixotropic behavior for dispersed solutions which increased with increasing hydrolysis and glycerin and decreased with increasing temperature. The degree of thixotropy is higher for CyOH (d) compared to Cy (d).
Agro paris tech, France
Amandine Flourat is researcher and head of chemistry department at Chaire ABI from 2012. The aim of Chaire ABI is the valorization of agricultural coproducts through microbiology, process engineering and green chemistry. Amandine Flourat develops new synthetic pathways using biocatalyst and biobased products to access high value molecules and new polymers.
Climate change and the depletion of fossil resources lead to a transformation of polymer industry. Now, demands are for sustainable polymers offering a wide range of applications. In this mood, we dedicated our self to the synthesis and the characterization of a new class of biobased aromatic polymers able to be degraded in aqueous media presenting a wide range of properties. To know about the potential field of application, we studied thermal stabilities, determined by ATG, which are higher than 270 °C, and glass transition temperatures. These ones are tunable depending of monomers’ flexibility and hydrogen bonding but always superior at 100°C. Then antiradical activities are determined by DPPH scavenging test. Whereas antimicrobial properties are tested on Gram + and Gram - bacteria.
University of Pisa, Italy
Norma Mallegni PhD student in University of Pisa, Department of Civil and Industrial Engineering, Master Degree in Chemistry, is working on copolymerization, blending and processing of biobased polymers for tuning properties and sustainability of biobased materials.
Green composites based on polyhydroxyalkanoates (PHA) with 10 to 20 wt% natural fibres were manufactured by extrusion and characterized. Two different types of fibres were used: fibrous wastes of the seagrass Posidonia Oceanica (PO) and sawdust (SD). PHA was successfully compounded with both fibres using 10 wt % acetyl tributyl citrate (ATBC) as plasticizer. Thermal, rheological, mechanical (tensile and Charpy’s impact tests) and morphological characterizations of the developed composites were conducted. The composites showed good thermal and mechanical properties, the impact energy-absorbing capability was markedly increased with increasing the fibre loading of PO or SD compared with that of the unfilled material.
The biodegradability of the composites based on PHA and PO fibres was assessed in sea water using standardized procedures based on the carbon dioxide evolution. Whereas, the biodegradability of the composites based on PHA and SD was assessed by measuring the amount of carbon mineralized during incubation under composting conditions. Both tests showed that the presence of the fibres facilitated the disintegration of the composite films increasing their biodegradation rate in the two different investigated environments.
Hamburg University of Technology, Germany
Yunlong Jia is a doctoral candidate in Hamburg University of Technology with his research topic ‘durability of flax fiber reinforced bio-composites for structural applications’. He graduated with M.Sc. in mechanical engineering in 2012 and published four articles during his graduate program. After graduation, he was finically supported by the China Scholarship Council to conduct his research in the Institute of Polymer Composites.
The recent years has witnessed a rising development of bio-composites in a wide range of applications. Much effort has been devoted to improve the performance of bio-composites. One of the most important aspect lies in the optimization of the interfacial properties. The intrinsic hydrophilic properties of natural fibers not only cause incompatibility with matrix but also make the interfacial regions very sensitive to weathering effects. The changing ambient temperature, humidity might cause degradation in the interfacial regions in the long term, which is among the least understood components of bio-composites. This study aim at a better understanding of hydrothermal degradation and its effects on the interfacial properties of flax fiber/bio-based polyurethane composites.
Experiments were elaborated at two scales. Single yarn fragmentation tests were performed as a reliable way to focus on the fiber/matrix interfaces. Corresponding unidirectional tensile tests were performed to investigate the influences of degradation at the scale of composites. It is found that interfacial bonding between flax fibers and matrix were weakened by the degradation caused by the hydrothermal effects. Results obtained at two scales correlate with each other well. Degradation in the interfacial regions can be well reflected by indicators from single yarn fragmentation tests like fragmentation development, fragmentation length distributions, and crack shapes etc. Interestingly, not only water absorption, but also water desorption cause degradation of fiber/matrix interfaces