Evaluation of the transport properties of poly(3-hydroxybutyrate) and its 3-hydroxyvalerate copolymers for packaging applications

Poly(3-hydroxybutyrate) (PHB) and ist 3-hydroxyvalerate containing copolyme rs form a family of fully biodegradable polyesters with many potential appl ications. In this work, the results obtained in our laboratory concerning c arbon dioxide, water and organic solvent transport through PHB and three lo w 3-hydroxyvalerate copolymers are reviewed. Comparison established between the former results and some data taken from the literature, have revealed that PHB and the above mentioned copolymers show transport properties simil ar to other common thermoplastics such as PVC and PET, particularly in the case of carbon dioxide and water. Consequently, PHB and copolymers can be c atalogued as good barrier materials against these penetrants. On the other hand, these biopolymers show a low barrier character against organic compou nd permeation. All these features conform a good balance of physicochemical properties for these polyhydroxyalkanoates, which may take them suitable f or several applications, including its use in biodegradable packaging mater ials.