Synthetic Biodegradable Polymer - Polymer Chemistry and Material Selection

Polymer Chemistry and Material Selection

When investigating the selection of the polymer for biomedical applications, important criteria to consider are;

• The mechanical properties must match the application and remain sufficiently strong until the surrounding tissue has healed.
• The degradation time must match the time required.
• It does not invoke a toxic response.
• It is metabolized in the body after fulfilling its purpose.
• It is easily processable in the final product form with an acceptable shelf life and easily sterilized.

Mechanical performance of a biodegradable polymer depends on various factors which include monomer selection, initiator selection, process conditions and the presence of additives. These factors influence the polymers crystallinity, melt and glass transition temperatures and molecular weight. Each of these factors needs to be assessed on how they affect the biodegradation of the polymer. Biodegradation can be accomplished by synthesizing polymers with hydrolytically unstable linkages in the backbone. This is commonly achieved by the use of chemical functional groups such as esters, anhydrides, orthoesters and amides. Most biodegradable polymers are synthesized by ring opening polymerization.