A renewed interest in aliphatic polyesters has resulted in developing materials important in the biomedical and ecological fields. Mainly materials such as PLA and PCL homopolymers have so far been used in most applications. There are many other monomers which can be used. Different molecular structures give a wider range of physical properties as well as the possibility of regulating the degradation rate. By using different types of initiators and catalysts, ring-opening polymerization of lactones and lactides provides macromolecules with advanced molecular architectures. In the future, new degradable polymers should be able to participate in the metabolism of nature. Some examples of novel polymers with inherent environmentally favorable properties such as renewability and degradability and a series of interesting monomers found in the metabolisms and cycles of nature are given.

Polymericmaterials, both"inert"anddegradable, constantlyinteractwiththe surroundings. Because of this interaction changes take place in the polymer matrix and small molecules are released to the environment. Reliable me- ods for testing biodegradability and environmental interaction of renewable resources and biodegradable polymers are required to answer the rema- ing questions concerning the environmental impact of these future materials. Inthecaseofdegradablepolymersmultiplefactorsaffectthedegradation process and small changes in the chemical structure or product formulation may change the susceptibility to degradation or cause different degradation product patterns, rendering the product less environmentally adaptable. - velopment of sustainable polymeric materials also demands the development of more migration-resistant polymer additives. Chromatographic techniques especially gaschromatographyandliquidchromatographypreferentially c- pled to mass spectrometric detection are ideal tools for studying these low molecular weight compounds and polymer-environment interactions. In the ?rst chapter of this volume chromatographic ?ngerprinting and - dicator product concepts are presented as tools for evaluating polymeric - terials. These concepts have great potential in evaluation of degradation state andlife-time/service-life ofpolymericmaterials, evaluation ofanti-oxidant or pro-oxidant systems, degradation mechanism and processing parameters as wellasrapidcomparisonandqualitycontrolofmaterials.Thesolid-phase- croextractiontechniquehasrapidlyfoundapplicationsinnumerous?elds.The second chapter reviews the extraction of polymer degradation products and additives, monomer-rests, odour compounds, migrants from packaging and medicalproductsaswellasextractionofpolymeradditivesfromenvironm- talsamplesandbiological?uidsbysolid-phasemicroextractiondemonstrating the high versatility and potential of this technique also in polymer analysis.

A renewed interest in aliphatic polyesters has resulted in developing materials important in the biomedical and ecological fields. Mainly materials such as PLA and PCL homopolymers have so far been used in most applications. There are many other monomers which can be used. Different molecular structures give a wider range of physical properties as well as the possibility of regulating the degradation rate. By using different types of initiators and catalysts, ring-opening polymerization of lactones and lactides provides macromolecules with advanced molecular architectures. In the future, new degradable polymers should be able to participate in the metabolism of nature. Some examples of novel polymers with inherent environmentally favorable properties such as renewability and degradability and a series of interesting monomers found in the metabolisms and cycles of nature are given.