Biodegradable polymers are materials that break down, making them safe for the environment. Polymers serve as major components of materials, such as plastics and gels. The need for biodegradable polymers grew by 5 to 10 per cent in 2009, according to SRI Consulting. Consumers want more fossil fuel and gas independence and are also worried about the environment. Europe is especially interested in biodegradable polymers, given their space limitations and growing landfills.
For a material to be considered biodegradable, measurable tests must verify that microorganisms can break down the materials through enzymatic action, producing carbon dioxide, water and biomass. Polymers with multiple organic atoms within them have a high biodegradability rate, so engineers can make polymers biodegradable by including chemical linkages such as anhydride, ester or amide bonds. Amide bonds are linked to nitrogen, ester bonds are based on oxygen and hydrogen, and anhydride bonds are attached to an oxygen atom.
Plastics are a major part of packaging. Since packages are often disposed of after use, they can harm the environment if they are not biodegradable. One way to create biodegradable polymers is to extract starch, cellulose and fibre from various kinds of plants. These polymer sources allow manufacturers to create plastics that are not only environmentally friendly, but also more economical. Engineers take natural polymers that break down on their own and modify them so that they meet the needs of the engineering application.
Scientists developed biodegradable polymers for products that are poured down the drain, such as detergents and cosmetics. The water-soluble polymers are conventionally made from substances such as maleic anhydride, acrylic acid, methacrylic and other monomer combinations, which are not biodegradable. They remain in oceans and lakes. However, researchers have developed versions of these products that are made using modified forms of starches, fibres and cellulose so that they safely break down in the environment.
Biodegradable polymers are increasingly needed as various economies develop, increasing the need for polymers used in packaging and other industrial processes. When polymers accumulate in excessive numbers, they can negatively impact plants by interfering with the absorption of nutrients. Another biodegradable option is a group of polymers that have hydrolysable backbones, known as polyesters. Most polyesters are biodegradable, but some polyesters, such as polythene terephthalate, are not biodegradable.
- Sigma-Aldrich: Biodegradable Polymers
- The Society for Engineering in Agriculture, Food and Biological Systems; Biodegradable Polymers: Past, Present, and Future; M. Kolybab et al; 2003
- Peking University; Biodegradable Polymers for the Environment; Richard A. Gross et al; August 2002
- Pr. Luc Averous: Biodegradable polymers (Biopolymers)
- SRI Consulting; Biodegradable Polymers; Michael Malveda; January 2010
- "ch.imperial.ac.uk:" Advanced Polymer Synthesis