Whole Green Composites
Whole green composites are made from renewable resource based polymer (biopolymer) and biofiller. Whole green composites are recyclable, renewable, triggered biodegradable and could greatly reduce the dependency on fossil fuels when used in interior applications. Whole green composites could have major applications in automotive interiors, interior building applications and major packaging areas.
The major research areas in whole green composites include:
- Renewable resource-based biodegradable polymers (polyhydroxyalkanoates, polylactides, cellulose esters and starch plastics)
- Petroleum-based biodegradable polymers (aliphatic polyesters and aliphatic-aromatic copolyesters)
- Soy-based bioplastics (soy oil-based thermoset resins and soy protein-based thermoplastic)
- Polyols from plant oils and biobased polyurethanes
- Biobased polyesters/epoxies and their biomaterials
Natural Fiber Composites/Biocomposites
Inconsistency in petroleum pricing and increasing environmental awareness have created demand for natural fiber composites, or biocomposites, as potential substitutes for existing synthetic fiber composites. Though biocomposites are lightweight, they retain impressive strength, stiffness, and provide thermal insulation. They are both recyclable and carbon dioxide neutral, as well as cost effective and easily available.
Petroleum based polymers, when reinforced with biofibers, biopolymers (renewable resource based polymer) and synthetic fibers can be treated as biocomposites. Jute, hemp, kenaf, flax, Pineapple leaf, Banana fiber, sisal, henequen, cotton, kapok, coir are being used as biofiller in thermoplastics and thermosetting polymers to develop composites through reactive extrusion, injection molding, thermoforming, resin transfer molding and compression molding techniques. Other materials used as biofiller in composites include Chicken feather, bone, scales of marine animals and lamb wool. Attempts are currently being made to promote the recycling of agricultural waste fibres such as wheat straw, soy stalk, corn stalk, and grass fibres (switch grass and miscanthus) into reinforcing biocomposite fillers.
The major research areas in biocomposites include biofiber reinforcement in:
- Petroleum-based conventional polymers (polyolefins, polyvinylchlorides, polycarbonate, acrylobutadienestyrenes, nylons etc.)
- Petroleum-based biodegradable polymers (polycaprolactum, polybutylenesuccinate, ecoflex, esterbio etc.)
- Polytrimethylene terephthalate and blends
- Thermoset resins (polyester, epoxies etc.)
Biodegradability and Compostability Studies of Biopolymers and Green Composites
Compostable Plastics are a new generation of plastics that undergo degradation by biological process during composting to yield carbon dioxide, water, inorganic compounds and biomass at a rate consistent with other known compostable materials while leaving no visible or toxic residue. Compostable materials made from biopolymers are being made acceptable for collection by municipal organic waste collection systems. Current legislation encourages polymer processors to seek environmentally friendly materials with sustainable life cycles as an alternative to traditional polymers.
BDDC is actively pursuing biomaterials and green composites made from plastics that meet the established specifications of municipal and industrial aerobic composting facilities. For plastics and composites made from plastics to compost satisfactorily, they must biodegrade at a rate comparable to known compostable materials, without diminishing the value or utility of the compost produced. The compostable plastic materials currently on the market, including packaging made from plastics, must meet labelling requirements before being marked as "compostable in municipal and industrial composting facilities." The facility at BDDC conducts research evaluations of materials according the required specifications of compostability and degradability. The outcome of this research helps in designing biomaterials that satisfy the disposal needs of municipal organic waste collection systems.
Lignin and Its Application with Polymers
Lignins are a major industrial byproduct that are also highly functional biopolymers. They possess primarily alkyl-aryl ether linkages, aliphatic and aromatic hydroxyl groups which offer potential for the development of renewable polymeric material blends. North America has an estimated lignin potential of 300 M ton/yr, including production from chemical pulp mills and bioethanol industries. Lignin is mainly used as a boiler fuel. Currently, only a small percentage is being salvaged through chemical recovery for value added applications.The value of lignin improves the industries' economy and could serve as a source for renewable polymeric materials. Research on lignin-reinforced thermoplastics and thermosetting polymer composites are in progress. Attempts are underway to develop low cost, recyclable, fully biodegradable composites from various renewable as well as non-renewable sources that could substitute existing plastics in automotive, building and packaging applications.
Value Added Utilization of Protein Rich Meals for Green Packaging Applications
Biofuel production is associated with various undervalued and underutilized coproducts. One major coproduct from biodiesel industry is protein rich meal, currently being used as cattle feed. However, the remarkable growth of the biodiesel industry has created an oversupply of protein rich meal as cattle feed. Diversification in utilization of this product creates a value proposition for biofuel industries. It's utilization for green packaging reduces the dependency on petrobased polymers. "two birds, one stone"!
The BDDC centre utilizes Soymeal, Distiller's Dried Grains with Solubles (DDGS) DDGS, Canola meal and Jatropha meal from biodiesel industries for research on green packaging applications. The BDDC uses the whole meal rather than using it to obtain pure protein. This is accomplished through reactive blending, compatibiliztaion chemistry and thermoplastic processing. A recent innovation at the BDDC is the use of crude glycerol in this field.