Starch is a reserve source of plant carbohydrates so it is commonly found in nature. Starch derived from various plants have different physical and chemical properties. Starch is extracted from seeds such as corn and wheat, from roots and tubers such as cassava, potatoes, starches dong is the main industrial use
Starch is a high molecular carbohydrates including D-glucose units linked together by α-glucoside links. Approximate molecular formula is (C6H10O5) n where n has a value of from a few hundred to ten thousand. Starch has white granules was created by two amilozo and amylopectin. Amilozo the linear polymer composed of D-glucose units linked by α-1,4- linked glucoside
Part of structure amilozo
Amylopectin is branched polymer, in addition to normal glucose chains have also branched chain linked to the main chain linked by α- 1,6-glucoside
Part of amylopectin structure
Based on the nature of the changes occurring in molecular starch, Kovalxkaia divided modified starch by chemicals into two categories: cutting starch and instead starch .
Cutting starch Group: the starch molecules occurs cutting CO link between the monomer and the other links, reduced molecular weight, appearing some new links within and between molecules. The structure of the starch particles can more or less broken. This starch Group has many applications such as acid-modified starch is used to coat paper, the durability of paper, print quality improvement … In the food industry, this type of starch used to create structures gel structure in the manufacture of confectionery.
Oxidation starch are also classified this group. Some starches are oxidation by KMnO4 in acidic medium was used instead agar, pectin in the manufacture of confectionery, ice cream, dairy products, as well as in cans. The oxidation starch products are also used in the major bread to increase the hold time of dough gas, reduce fermentation time and increase the quality of the bread. Starch is oxidized by hypochlorite, H2O2, HI and its salts are widely used in the paper industry.
Instead starch Group: the starch group that their properties change due to the hydroxyl group at carbon 2, 3 and 6 associated with the chemical radicals or copolymer with a high molecular compound, or 2 polysaccharides circuit can be attached to each other by a bridge-linked.
The modified starch level is characterized by the world (Degree of substitution – DS). DS is the number of hydroxyl groups that are on the AGU (anhydrous glucose unit). So, DS can the value of about 0-3. In this case the properties of starch significantly altered. Usually this type of starch has high viscosity and adhesion strength (used to produce the product to storage) as acetate starch, phosphate starch, oxidation starch…
Some applications of modified starches for industrial
- In the construction industry starch is used as a binder concrete, putty clay, limestone, wood glue, wood molding, additives for paints.
- In the cosmetics industry and pharmaceuticals, modified starch is used as bleaching powder, make up, additives for soaps, hand creams, excipients.
- The mining industry, starch is used in ore flotation, oil drilling fluid emulsion.
- The paper industry, modified starch is manufactured using surface coatings, ingredients paper ash, products diapers for children.
- The textile industry, modified starch used in sizing, printing.
- For other industries, modified starch is used as a biodegradable plastic film, dry batteries, leather, hot melt glue, binders, molding, metal sintering additives.
MODIFIED STARCH FOR MOSAIC TILES
Modified starch is used as an glue for tiles together with paper can withstand the pressure. This method is very convenient for the construction of high-rise buildings, buildings … to facilitate the construction and sanitation
Instructions for use:
- Phase modified starch according to water ratio of 1: 1
- Gelatinized starch
- Dilute just gelatinized starch with water ratio of 1: 3 (1 gelatinized starch: 3 water) and then stirring.
- Use starch as mosaic tile glue on the paper.
Exterior wall inax mozaic tiles cladding process :
Put plastic mold on blister tiles
Spread the grout on blister tiles
Take off plastic mold on blister tiles
Cladding blister tiles on the wall
Peel the paper on tile surfaces
Clean glue paper
Spread meji tile eyelid
Cleaning tile surfaces