Polymers gluten

The ability of a degradable plastic to decay depends on the structure of its polymer chain. Biodegradable plastics are often manufactured from natural polymers, such as cornstarch and wheat gluten. Micro-organisms in the soil can break down these natural polymers. Ideally, a biodegradable plastic would break down completely into carbon dioxide, water, and biomass within six months, just like a natural material. 

Zhang, X., Do, M.D., Hoobin, P. and Burgar, I. 2006. The Phase Composition and Molecular Motions of Plasticized Wheat Gluten-Based Biodegradable Polymer Materials Studied by Solid-State NMR Spectroscopy. Polymer, 47, 5888-5896. 

Thermo-mechanical analysis (TMA)26 and DMTA292 have been used to study the viscoelastic properties of bread, a composite two-phase system. The moisture dependence of Tg was similar to that of pure amorphous starch and gluten.242,282 293-295 At the moisture content of bread, water exerts its full plasticization effect on the composite polymer matrix, reducing the effective Tg to about -10° to - 12°C,26,292 well below normal shelf life storage temperatures of this product. 

Within the context of proteins as polymer materials the number is still further limited, since only very few are available in sufficient bulk at low extraction cost to consider post-processing them into useful materials. More particularly, the fibrous proteins, such as collagen, certain plant proteins such as gluten, the component of wheat responsible for giving the elastic properties to bread doughs, and proteins produced from soy have been exploited to a limited degree, as we shall see below. In recent years there has also been renewed interest in fibrous silk proteins, from silk worms, spiders (as web-silk) and also from bioengineering routes. 

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