Granular starch

Starch, granular mica, fine particulate starches, mixture of [337]... 

Starch Granular size (fim) Amylose (%) Degree of polymerisation Amylopectin (%)... 

The use of bromine in alkaline media resulted in the formation of uronic acids.416,417 Oxidation to some non-uronic acid products, (carbonyl compounds) accompanied the major oxidation pathway.418-420 The 2,2,6,6-tetramethyl-l-piperidinyloxy-mediated oxidation by hypobromite was highly selective for the 6-OH groups of the glucose residues.421 Potassium bromate (HB1-O3) was also used.338 The kinetics of oxidation with bromine at pH 6-8 has been studied 422 It was observed that oxidation decreases the heat and temperature of gelation as the oxidation proceeds. Simultaneously, the molecular weight of starch and the viscosity of its aqueous solutions decreased. Subsequent reduction of the oxidation products increased the viscosity. Microscopic observations revealed that the starch granularity vanished at a low level of oxidation.423... 

Under proper conditions of temperature, pressure, water content, and shear, the starch granular structure is totally disrupted (43). The starch exists as a continuous phase and in this state is called thermoplastic starch (TPS). TPS can be extruded, injection-molded, or formed into foams (44-48). 

FIGURE 15.1 Morphologies of PLA blended with (a) starch granular (30%) and (b) gelatinized starch (30%) observed by SEM. Poor adhesion between starch and PLA can be clearly observed by the gaps at the interface between the two phases. 

Leszczydski W. Attempts to simplify the methods of determination of potato starch granularity. Starch 1987 39 (7) 223-225. 

Starch oxidation was investigated as early as 1829 by Liebig. The objective, as with other modifications, was to obtain a modified granular starch. The oxidant commonly employed is sodium hypochlorite, prepared from chlorine and aqueous sodium hydroxide. This reaction is exothermic and external cooling must be provided during preparation of the oxidant. 

PregeEtinized Starches. Suspensions of starches and starch derivatives can be gelatinized/cooked and dried to yield a variety of products that can be dispersed in cold water to yield pastes comparable to those obtained by cooking granular starch products. These products are made for... 

Starch is a widely distributed material which occurs in roots, seeds, and fruits of plants. For commercial use, com is the principal source, though wheat and potatoes are also used. Starch is extracted by grinding with water, filtering, centrifuging, and drying, a process which yields starch in a granular form. 

A crosslinked starch was described as a fluid loss additive for drilling fluids [632,1626]. The additive resists degradation and functions satisfactorily after exposure to temperatures of 250° F for periods of up to 32 hours. To obtain crosslinked starch, a crosslinking agent is reacted with granular starch in an aqueous slurry. The crosslinking reaction is controlled by a Brabender... 

A fluid loss additive is described that consists of granular starch composition and fine particulate mica [337]. An application comprises a fracturing fluid containing this additive. A method of fracturing a subterranean formation penetrated by a borehole comprises injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing the additive in an amount sufficient to provide fluid loss control. 

---