Algix LLC, Bogart, Georgia, USA, is blending high-protein-content algae with thermoplastics to make new bioplastics for disposable and durable applications.
Algix says it is working on a different source. Ryan Hunt, director of R&D at Algix, wants dairy farmers to raise algae as a new cash crop, while remediating water runoff. Instead of causing algae blooms in local ponds and streams, farmers can use a commercial remediation system called an Algal Turf Scrubber, available from HydroMentia Inc., Ocala, Florida, USA (www.hydromentia.com). It has a large (3.5 acre) PE mat graded at a slight 2[degrees] angle, over which polluted water flows constantly. In about a month, a thick mat of algae grows, which can be removed by a tractor pulling a scraper. Mats of algae are currently composted, landfilled, or fed to cattle. Algix wants to make them into bioplastics.
Algix works with Ven Consulting LLC in Melbourne, Florida, USA, (www.venconsultingllc.com) to harvest, dry, and mill algae biomass for conversion into plastics. The best protein sources, Algix says, are two micro-algae, Chlorella vulgaris and Spirulina platensis, and filamentous algae and macrophytes from the Lemna and Cladophora genuses. Chlorella is 55 dry wt% protein, 15% starch, and 18% fat with low ash and fiber. Spirulina is 55% protein, 11% starch, and 5% fat, also with low ash and fiber. Cladophora can have up to 40% protein, 20% fiber, and 30% ash. Kimberly-Clark's patent also describes plasticizing a third micro-algae, Nanochloropsis, a popular strain for algal oil production. All are less than 115 microns in size. Research at the University of Georgia has also shown that nano-cellulosic fibers from duckweed demonstrate performance similar to that of aramid fibers (e.g., DuPont Kevlar).
Pure algae plastic made by compression molding is hard like polystyrene, but brittle. Algix blends powdered algae with powdered HMW HDPE (53-75 micron) with a melt temperature of 144[degrees]C with glycerol as a plasticizer for flexibility. Algae biomass burns at 200[degrees]C, which limits formulations to polymers with melt temperatures below 190[degrees]C. Algix has presented data on compression-molded blends of 30/50/20 HDPE/algae/glycerol, but has tested over 30 formulations for extrusion compounding and injection molding, including blends of algae and macrophytes with PLA to make 100% bioplastics. Compounding was done on a 21mm-diameter twin-screw extruder in the Polymers Center of Excellence (www.polymers-center.org) in Charlotte, North Carolina, USA. www.algixllc.com.
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|Title Annotation:||industry NEWS and NOTES|
|Date:||Jan 1, 2012|
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