The term “functional polymers,” when used in the general sense [I], represents a very broad range of polymers embodying a variety of highly specific “chemical,” “physicochemical,” or “biophysical” functions as compared with the mechanical functions of the more commonly used polymeric materials. In such a broad sense. functional polymers include many types and varieties of chemical structure, morphology, and functionality. For example, a functional polymer may be reactive toward a specific or complementary substrate; it may inhibit, delay, or promote its own degradation; it may act as a catalyst, molecular carrier, or temporary (reversible) masking agent; it may possess photo or electric conductivity; or it may be medicinally active. biodegradable, or biocompatible.