The development of biopolymer-based nanostructured materials : plastics, gels, IPNs and nanofoams

The ability to design products with structural features on a nanometric scale is a major technology driver in materials research Nanostructured materials are defined as materials with structural features on a sub-micron scale determining specific properties They consist of materials such as metals, polymers, ceramics, composites and biomaterials Future applications include ultra precise drug-delivery, transparent nanofoams, nanoelectronics, coatings and ultraselective molecular sieves The preparation of biopolymer-based nano-structured materials only recently gained attention The main disadvantages of biopolymer materials like plastics and coatings are water sensitivity or low mechanical strength New ways were developed, improving the properties of soft biopolymeric materials, such as the development of starch colloids, biopolymer interpenetrating networks and organic-inorganic hybrids A description is given of several new classes of polysaccharide or protein based materials

Crystallinity in starch plastics: consequences for material properties

The processing of starches with biodegradable additives has made biodegradable plastics suitable for a number of applications. Starch plastics are partially crystalline as a result of residual crystallinity and the recrystallization of amylose and amylopectin. Such crystallinity is a key determinant of the product's properties. This article describes the influence of processing and storage conditions on starch crystallinity and offers possible explanations for the various properties of starch plastics, in particular for the problems associated with ageing, in terms of the different crystalline structures