Biopolymer Basics

Biopolymer Basics:
Polymers are long chain molecules with a wide range of physical and chemical properties. One of the main advantages of the polymer materials is the ease of fabrication to produce various shapes (rod, film, fiber, sheet, etc.). The advances in polymer chemistry have made it possible to tailor the properties of polymers for specific application.

1- Classification of Polymers:
Polymers can be classified according to their sources, chain structures, thermal
behaviors, stabilities, etc. , as discussed below.
1.1 Source
By source, polymers can be divided into two groups. They are naturally occurring
polymers and synthetic polymers.

Polymer Stability:
Polymeric materials can be divided into two main classes — biostable and biodegradable polymers according to their stability when they are used in contact with biological systems.
Biodegradable polymer is a polymer in which the degradation is mediated at least partially by a biological system. The biodegradation of a polymer can be caused by hydrolytic, enzymatic or bacteriological degradation processes occurring within a polymer matrix. The degradation process will cause a deleterious change in the properties of a polymer due to a change in the chemical structure.
Most of the biodegradable polymers discovered so far contain hydrolysable linkages, such as ester and amide in their backbone structure. Among them, the flexible ester containing polymers, and in particular aliphatic polyesters, appear to be the most attractive biodegradable polymers because of their useful biodegradability and their versatility regarding physical, chemical and biological properties. Table 3 listed some examples of biostable and biodegradable polymers for biomedical applications.