Plastics, amylose triacetate

Typical stress-strain curves for this unplasticized amylose triacetate film and for film containing 20% dibutyl phthalate plasticizer are shown... 

Amylose triacetate prepared from butanol-precipitated starch may be plasticized with almost any of the common plasticizers which are applicable to the plasticization of cellulose triacetate. For example, some suitable plasticizers are dimethyl or diethyl tartrate, tributyl citrate, tributyl phosphate, tricresyl phosphate, polyethylene glycol, and pentaerythritol tetraacetate. Addition of only 10-20% plasticizer is sufficient to give amylose triacetate films a useful and lasting degree of... 

Paralleling their film-forming properties, these amylose triacetates can be molded into strong, tough plastics, but the amylopectin triacetates yield only very brittle products. Similarly, Mullen and Pacsu have shown that whole starch acetate produces clear, transparent, molded pieces which, however, are brittle. 

Since amylopectin acetate produces only brittle films and plastics, its molecules probably have a non-linear structure which may be branched or coiled. A further striking difference between amylose triacetate and amylopectin triacetate is that the former can be obtained in the form of a highly fibrous mass, whereas the latter occurs only as a fine powder. 

The performance of the TPS/MMT nanocomposities using different kinds of starch have been studied. Nejad et al. [251] developed nanocomposites through the melt intercalation of nanoclays and starch esters from high amylose starch. Starch acetates (SAs) and starch propionates (SPs) were tested in combination with glycerol triacetate (triacetm) as a plasticizer for concentrations up to 30 and 20 wt %, respectively, with different types of organomodified and unmodified... 

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