Biodegradable Materials
“Biodegradable matter is generally organic material such as plant and animal matter and other substances originating from living organisms, or artificial materials that are similar enough to plant and animal matter to be put to use by microorganisms. Some microorganisms have a naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals. Major methodological breakthroughs in microbial biodegradation have enabled detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms providing unprecedented insights into key biodegradative pathways and the ability of microorganisms to adapt to changing environmental conditions.”
“Products that contain biodegradable matter and non-biodegradable matter are often marketed as biodegradable.”
"Biodegradable plastics. There are two main types of biodegradable plastics in the market: hydro-biodegradable plastics (HBP) and oxo-biodegradable plastics (OBP). Both will first undergo chemical degradation by hydrolysis and oxidation respectively. This results in their physical disintegration and a drastic reduction in their molecular weight. These smaller, lower molecular weight fragments are then amenable to biodegradation."
"OBPs are made by adding a small proportion of compounds of specific transition metals (iron, manganese, cobalt and nickel are commonly used) into the normal production of polyolefins such as polyethylene (PE), polypropylene (PP) and polystyrene (PS). The additives act as catalysts to speed up the normal oxidative degradation, increasing the overall process by up to several orders of magnitude (factors of 10)."
(Wikipedia, Biodegradable Materials, 4/29/2011)
Biodegradation
Materials
Polycaprolactones
Polylactic Acid (PLA)
Polylactic Acid Biodegradable Materials
Recent US Patents
9/27/2011
8,026,301
Biodegradable polymer composition
Sumanam of BNT Force Biodegradable Polymers, India, developed a biodegradable additive polymer composition useful for the preparation of biodegradable plastic products based on a mixture of (i) a polymer selected from Polyethylene, polypropylene, poly styrene, poly vinyl chloride or a mixture thereof (ii) Cellulose (iii) Amides (iv) nutrients selected from Blue green algae and/or Yeast and (v) Water. This composition can be mixed with a virgin polymer to get a master polymer. The master batch composition may be mixed with a virgin polymer, which is useful for preparing products which are biodegradable. (RDC 10/3/2011)
11/2/2010
7,825,179
Biodegradable resin composition, production method therefor, and product molded or formed therefrom|
Kawahara et al of Unitika Ltd., Japan has produced a transparent biodegradable resin. The biodegradable resin composition consists of a biodegradable polyester resin, a phyllosilicate, and a polyether phosphate compound, a polar wax and jojoba oil. (RDC 3/2/2011)
9/28/2010
7,803,298
Molding Material, Molded Part, and Method for Manufacturing Them
Synthetic polymeric materials are a disposal problem because of non-biodegradability as well as the carbon dioxide emission generated during degradation and global warming. These problems can be avoided with biodegradable resins. However, these biodegradable resins such as starch, cellulose and polylactic acid are hard with poor impact resistance. Other biodegradable resins such as polybutylene adipate terephthalate, polycaprolactone or polybutylene succinate are flexible but have low strength. Kanazawa of Sumitomo has developed biodegradable molding pellets formed from crosslinked powders impregnated with a plasticizing polymerizable monomer. In one example, a biodegradable resin such as cellulose acetate or polylactic acid is crosslinked with triallyl isocyanurate by kneading and irradiating with ionizing radiation. This crosslinked product is, then, pulverized, mixed and swollen with a plasticizer or monomer such as an acrylic or styrene monomer. After impregnation the monomer is polymerized by heat or radiation. This mixture is, then, pelletized for extrusion or molding.
Recent Journal Articles
Synthesis of functionalizable and biodegradable polymers via ring-opening polymerization of 5-benzyloxy-trimethylene carbonate and ε-caprolactone
(2204–2210)Journal of Applied Polymer Science 123 #4 (2012)
Lai et al of Sichuan University, China, copolymerized CL with amorphous 5-hydroxyl-trimethylene carbonate (HTMC) to solve the problem of high hydrophobicity and crystallinity. The 5-benzyloxy-trimethylene carbonate (BTMC) was synthesized to copolymerize with CL, then hydrogenolyzed to obtain hydroxyl pendant groups. The PCL segments in the copolymers crystallized below 16.8%. BTMC molar content and the crystallinity of the copolymers increased after hydrolysis. With the introduced hydroxyl pendant groups, the deprotected copolymers improved their hydrophilic property significantly, and the copolymer with 9.3% HTMC molar content had static water contact angle as low as 36.5°. (RDC 11/2/2011)
BIODEGRADABLE POLYMER COMPOSITES BASED ON AGRO-INDUSTRIAL COMPLEX WASTE
(T/35-T/38) International Polymer Science and Technology 38, #7 (2011)
Kirsh and Chutkina developed a strategy for filled biodegradable polymer composites based on agro-industrial complex (AIC) and packaging waste was studied with the aim of producing raw material and articles from it. PE film waste was used with AIC waste in the form of cacao husks, beet pulp, husks of buckwheat, rice, millet and sunflowers, and potato and maize pulp. Particular attention was paid to study of the physical/mechanical properties of filled biodegradable polymer composites. Mathematical modelling and tests on physical/mechanical properties suggested that beet pulp, cacao husks and rice husks were the most effective of these fillers for production of biodegradable polymer composites. Processes of biodegradation of polymer composites filled with AIC wastes were also examined. A mixed modifier based on a sorbent and bentonite was developed for production of biodegradable polymeric materials based on PE waste filled with 30-40% AIC waste. 2 refs. (Article translated from Plast.Massy, No.5, 2010, p.45-48) (RDC 10/4/2011)