Biopolymers, fibrous

Burchard, W., Eschwey, A., Franken, I., Pfannemuller, B. in Fibrous Biopolymers, Colston Papers No 26, London Butterworths 1974, pp. 365... 

Other Problems and Solutions in the Diffraction Analysis of Fibrous Biopolymers. 

This collection of papers was part of a unique symposium held during the 178th Meeting of the American Chemical Society. The symposium, Diffraction Methods for Structural Determination of Fibrous Polymers, had a pronounced international character, with scientists from 12 different countries. The speakers represented both the synthetic polymer and biopolymer fields, with contributions in each of the three classes of natural polymers nucleic acids, proteins, and polysaccharides. Most important, the symposium centered on methods and techniques for studying fibrous polymers, methods that are usually taken for granted despite their inadequacies. 

Our goal here is to have you compare and contrast some synthetic and natural polymers, such as nylon and silk, cotton and polyesters, so we will focus largely on biopolymers that are fibrous in nature and which are used as structural materials in plants and animals. We also aim to illuminate the way nature has married structure to function in such a marvelous fashion. Hopefully you will emerge... 

The addition of PEO has an influence on film destruction caused by an external destructive force (Figure 7). Without PEO, the external force created a clear-cut fracture surface, indicating the good adhesion between the two biopolymers. With the inclusion of PEO, the deformation created a fibrous surface. This can be seen more clearly from SEM and fluorescent microscopy. As shown in Figure 8 A and B, fibers were pulled out, extended, and then, broken, but still embedded in the matrix phase. We examine the fibers with confocal reflection and confocal fluorescence in two channels. It confirms that the main component of the fibers is PEO however, the biopolymers were either inserted or encapsulated within the fibers (Figure 8C). 

In nature, fibrous biopolymers have long been used in the reinforcement of extracellular biocomposites, inspiring the reproduction of this technology using native CNs as filler in a range of host polymer matrixes. Due to the highly crystalline nature of the cellulose nanoparticles, they possess attractive mechanical properties, such as an axial Young s Modulus of around 140 GPa, which is dependent on cellulose crystallinity and axial ratio [36]. When... 

Although the chemical structure of bacterial cellulose is identical to that of any other vegetable-based counterpart, its fibrous morphology (Fig. 1.20), as obtained directly in its biotechnological production, is unique and consequently the properties associated with this original material are also peculiar and promise very interesting applications. Details about this futuristic biopolymer are given in Chapter 17. 

Bionanocomposites are an ecological alternative to conventional nanocomposites based on petroleum-derived polymers, as they are based on biodegradable polymers obtained from renewable resources. Biomass is the source of agropolymers like starch and cellulose and also of monomers used to chemically synthesize polymers like polylactic acid (PLA). Other kinds of biopolymers, e.g., xanthan gum and poly (hydroxyalkanoates), are produced by microorganisms. Even though most of the bionanocomposites reported in the hterature are based on layered sihcates, the number of examples illustrating the use of fibrous clays in the preparation of new bionanocomposites is growing rapidly. 

---