Biodegradable polymers vs. recycling: What are the possibilities

Synthetic, petroleum-based polymer films are extremely stable and are commo nly used in agriculture, food packaging, fast-food restaurants, and on mili tary and commercial ships. However, their attractive stability is counterba lanced by two problems. One is that petroleum polymers contribute to the de mand for expensive imported oil. The other is their great resistance to bio degradation. When disposed they constitute a serious problem with very nega tive environmental impact. For example, the most frequently used polyethyle ne film takes 200 years to biodegrade. On the other hand, the use of agricu ltural biopolymers that are easily biodegradable not only would solve these problems but would also provide a potential new use for surplus farm produ ction. Unfortunately, films from agricultural polymers are initially inferi or to synthetic polymers mostly because of their difficult moldability and poorer physicochemical properties. However, specifically modified acidic ca rbohydrates and proteins with disulfide bondings may produce attractive alt ernatives.