Biodegradable Polymer from Casein

Casein is a naturally occurring macromolecule that accounts for approximately 80% of the protein content of cow s milk it is a phosphoprotein that can be separated into various electrophoretic fractions, such as aj-casein, /c-casein, fi-casein, and y-casein in which each constituent differs in primary, secondary, and tertiary structure, amino acid composition, and molecular weight (Ghosh et al., 2009 Audic et al., 2003 Barreto et ai., 2003]. It finds use in making adhesives and paper coatings. 

---

Many types of biodegradable polymers are available to biodegrade in a variety of environments, including soil, air, or compost. Biodegradable polymers are primarily made from com in the United States, but can be made from sugarcane, wheat, cellulose, collagen, casein, soy, or triglycerides. 

This does not mean we will see a mega-ton return to the old style polymers, such as casein plastics, cellulose nitrate and cellulose acetate. Many of these older polymers have severe deficits. For example, wool is eaten by moths and other insects cotton shrinks and does not hold a crease, unless treated with another polymer cellulose acetate is not solvent resistant, and cellulose nitrate is highly flammable. However, these older polymers come from renewable resources, which are also biodegradable, and this is a virtue in today s throw-away society. This alone should resurrect interest in natural polymers. Additionally, we have learned many vital things in the past century which will enable us to develop new and better polymers from biotechnology - polymers which... 

Audic, J.L., Chaufer, B. Influence of plasticizers and cross linking on the properties of biodegradable films made from sodium caseinate. Etir. Polymer J. 41, 1934-1942 (2005)... 

Prior to the 1930s all adhesives were based on natural products (eg, proteins such as animal blood, casein, soy protein). Use of adhesives from natural products steadily decreased thereafter with the development of synthetic polymers that had superior properties. Recently, renewed interest has been shown in using natural products to replace, entirely or in part, petroleum-based adhesive components with natural products, without sacrificing the performance levels achieved with modem petroleum-based adhesives. The purposes are often to reduce cost and dependence on petrochemicals, to reduce formaldehyde emissions, and improve selected properties (eg, biodegradability). 

---