Starch derived polysaccharides

Complexes with Dextrins, Polysaccharide Gums, Alginates, Pectins, and Starch Derivatives... 

Sparingly soluble or only swellable cellulose and starch derivatives other polysaccharides... 

He promoted the expanded use of modified starches and cellulose and investigated new derivatives of the two polysaccharides (1961-1969), with an emphasis on starch derivatives. He developed procedures for making sulfate half-esters of starch and other polysaccharides (1961-1963) and showed that 6-O-sulfated o-glucosyl units of starch could be converted into 3,6-anhydro-D-glucosyl units (1961). 

The presence of numerous hydroxyl groups able to react with formaldehyde makes starch-derived products suitable chemicals for formaldehyde-based resins. Research on this subject started many years ago and showed that in a number of applications it is possible to partially replace or extend urea formaldehyde, phenol formaldehyde and melamine formaldehyde resins without significantly affecting the finished product s performance. In many applications, adhesive systems based on formaldehyde resins incorporate a polysaccharide component. More than 4.5 Mio mto of formaldehyde-based resins have been produced in Western Europe alone. The use of carbohydrates allows lower consumption of oil-based resins and, consequently, reduced release of formaldehyde in the environment. 

In food industry, polysaccharides can be divided in two main groups starch derived products and nonstarch polysaccharides. Starch and their derivatives without any doubt lead the polysaccharides type used in the food industry. Due to their high availability, nutritional and technological properties, starches are in the genesis of a great number of food products known worldwide. ... 

Storage Polysaccharides. Starch and Starch Derivatives. Amylose and amlyopectin are the major components of starch granules found in food reserves of all green plants. Commercial starch is obtained from sources such as com, sorghum, rice, wheat, and potatoes. The compositions of the amylose and amy-lopectin vary with source. 

Natural polysaccharides, such as starch derived from com, wheat, rice or potato, and cellulose and its derivatives, are the main biopolymers employed in the development of green nanocomposites. The biodegradable thermoplastic polyester PLA, starch, and epoxidized vegetable oils are other examples of polymers widely used in the development of reinforced biopolymers. 

Glycoside hydrolases cleave the glycosidic bond in polysaccharides like starch, inulin, cellulose and their derivatives. The most important types are (a) the amylases (EC 3.2.1.1 and EC 3.2.1.2), which act on starch and derived polysaccharides to hydrolyse the a-1,4 and/or a-1,6 glucoside linkages, and (b) cellulase (EC 3.2.1.4), which act on (3-1,4 glucoside linkages in cellulose and derived polymers. 

G. Starkeether E ethers de I amidon S. are - starch derivates in which some or all of the hydroxyl groups of the polysaccharide are etherified. 

Small ECDs with good electrochromic properties have been realised with such SPE, ° the natural polysaccharides such as cellulose and starch derivatives can be modified by a plasticisation process with glycerol, and after addition of lithium salts, transparent films with high ionic conductivity can be obtained. " ... 

Catalytic oxidation ia the presence of metals is claimed as both nonspecific and specific for the 6-hydoxyl depending on the metals used and the conditions employed for the oxidation. Nonspecific oxidation is achieved with silver or copper and oxygen (243), and noble metals with bismuth and oxygen (244). Specific oxidation is claimed with platinum at pH 6—10 ia water ia the presence of oxygen (245). Related patents to water-soluble carboxylated derivatives of starch are Hoechst s on the oxidation of ethoxylated starch and another on the oxidation of sucrose to a tricarboxyhc acid. AH the oxidations are specific to primary hydroxyls and are with a platinum catalyst at pH near neutraUty ia the presence of oxygen (246,247). Polysaccharides as raw materials ia the detergent iadustry have been reviewed (248). 

Cross-Linking of Polyols. Polyols such as natural polysaccharides, eg, cellulose, starch, guar gum and their derivatives, and polyvinyl alcohol and its derivatives can be cross-linked by organic titanates. 

A similar procedure was adopted for synthesis of nanoparticles of cellulose (CelNPs). The polysaccharide nanoparticles were derivatised under ambient conditions to obtain nanosized hydrophobic derivatives. The challenge here is to maintain the nanosize even after derivatisation due to which less vigorous conditions are preferred. A schematic synthesis of acetyl and isocyanate modified derivatives of starch nanoparticles (SNPs) is shown in scheme 3. The organic modification was confirmed from X-ray diffraction (XRD) pattern which revealed that A- style crystallinity of starch nanoparticles (SNPs) was destroyed and new peaks emerged on derivatisation. FT-IR spectra of acetylated derivatives however showed the presence of peak at 3400 cm- due to -OH stretching indicating that the substitution is not complete. 

Biopolymers have diverse roles to play in the advancement of green nanotechnology. Nanosized derivatives of polysaccharides like starch and cellulose can be synthesized in bulk and can be used for the development of bionanocomposites. They can be promising substitutes of environment pollutant carbon black for reinforcement of rubbers even at higher loadings (upto SOphr) via commercially viable process. The combined effect of size reduction and organic modification improves filler-matrix adhesion and in turn the performance of polysaccharides. The study opens up a new and green alternative for reinforcement of rubbers. 

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