Materials [1] WHEYLAYER
Materials [1] WHEYLAYER “Whey proteincoated plastic films to replace expensive polymers and increase recyclability” project funded by European commission 7th framework programme under the Grant agreement no.: 218340-2. www. wheylayer.eu [2] “WHEYLAYER: the barrier coating of the future”, E. Bugnicourt, M. Schmid, O. Mc Nerney, F. Wild, Coating International, October 2010 [3] Cinelli, P. and A. Lazzeri. Le proteine nel settore degli imballaggi Wheylayer. Bio-Imballaggio derivato dal siero del latte in Biopolpack. 2010. Parma, Italy [4] Oli-PHA “A novel and efficient method for the production of polyhydroxyalkanoate polymer-based packaging from olive oil wastewater” proposal no.: 280604-2 successfully evaluated by European commission 7th framework NMP programme and awaiting negotiation within timeframes and at temperatures that are compatible with plastic recycling operations [3]. This results in the possibility of separating and independently recycling the other plastic layers in multilayer films, which are typically not recyclable, or even in the possibility of obtaining fully compostable materials if a biodegradable carrier film such as a PLA is used. The new WHEYLAYER bioplastic, which is presently being tested for food contact applications and its process is being scaled up to reach industrial production speeds, is getting closer to commercialisation and was recently presented at interpack 2011. More recently, an even more integrated approach was taken whereby the valorisation of all residuals from a given feedstock lead to polymers, biogas, fillers and other extracted natural compounds, and even clean water, all through environmentally friendly processes (figure 2). Biorefining is an attractive alternative to conventional fossil resource refineries, whereby microorganisms of different types can be used to convert biomass into energy or raw materials. The Oli-PHA project [4], which is still in its planning stages, aims to use photosynthetic microorganisms such as microalgae to produce polyhydroxyalkanoates (PHA) using wastewater generated during the olive oil milling process as a culture media. Indeed, over 250 different bacteria have been reported to accumulate PHA as carbon and energy storage materials. Among biodegradable bio-sourced plastics, PHA is one of the most promising since it maintains thermo-mechanical and barrier properties in the range of conventional plastics and is a good candidate to replace such conventional plastics as polyethylene terephthalate (PET). However, a major limitation to the wide uptake of PHA continues to be its high cost, mainly due to the substrates required for bacterial fermentation batch reactors. For PHA production to be economically viable, the production input costs need to be reduced; this is a key objective of the Oli-PHA project. By using a widely available feedstock based on residues, not only will this lower the cost of PHA production, it will also provide the agro-food industry with a solution for the sustainable management of highly polluting wastes. The work on yield improvement and valorisation of all compounds will also contribute to even greater cost effectiveness. All in all, Maxi-use represents a promising way forward for maximising the potential of bioplastics and their uptake in a wide range of applications. www.iris.cat 34 bioplastics MAGAZINE [04/11] Vol. 6
Materials by Xiuzhi Susan Sun University Distinguished Professor Kansas State University Advanced Research in Bionanocomposites The demand for biobased materials is driven by concerns for the environment and the need for sustainable development. Carbon backbones from plant-derived molecules have considerable potential as basic inputs for many materials currently produced from petroleum-based feedstocks with their associated environmental problems. The tremendous potential of plant-biobased materials has inspired scientists globally searching high performance and economic viable bobased materials. Bionanocomposites is a new ‘word’ that needs to be added to the dictionary, which is defied as the substance containing both biopolymer and nano materials (see graph). Biopolymer has to be the polymer derived from plant based feedstock, such as sugar-, lipid-, and or protein-based molecules, either through fermentation or chemical reaction. Nano materials can be naturally occurred or synthesized, and or can be metal nano crystal or biobased nanomaterials with all type of shapes (i.e., particle, wire, and sheet). The motivation of developing bionanocomposites is to improve biopolymer functional performances including one or more of those properties, such as mechanical strength, resilience, flexibility, lighter weight, color, fire-proof, durability, thermal stability, and electrical properties, etc. Two main approaches to develop bionanocomposites: thermal melt compounding method that a small amount of nano materials are dispersed in the biopolymer matrix during thermal processing (i.e., extrusion and molding); another way is to graft nano materials onto biopolymer chains through in situ biopolymer synthesis. In the last decade, numerous studies have been conducted on biopolymers (i.e., polylactic acid (PLA)) with various nanoparticles, including clays, carbon based nanofillers, SiO 2 , metal oxides, polysaccharide nanoparticles, etc., and PLA nanocomposites with improved mechanical properties, heat distortion temperature, glass transition temperature (Tg), thermal stability, and gas barrier properties have been developed. PLA has attracted extensive attention from both academia and industry because of its biodegradability, renewability, and properties comparable to many petroleum-derived polymers. An increasing amount of work is being published on PLA. PLA nanocomposites have been a hot research topic in the last decade due to their capability of enhancing the thermal, mechanical, and processing characteristics of pristine PLA. Research is still needed to further understand the complex structure-property relationships. Homogeneous dispersion of nanoparticles and strong interfacial interaction between PLA and nanoparticles are the two key issues in producing nanocomposites with desired properties. In addition, the lack of cost-effective methods to control the dispersion of nanoparticles in host PLA and interfacial bonding remains the greatest stumbling block to large-scale production and commercialization of PLA nanocomposites. www.ksu.edu/cbpd In situ polymerization Nanomaterials Biomonomer Bionanocomposites Thermal melt compounding Nanomaterials Biomonomer bioplastics MAGAZINE [04/11] Vol. 6 35
