What is a cationic starch?
Cationic starch is a modified starch. The cationic starches mainly used as wet-end starch. Although native starch can be used as wet-end starch, but cationic starches are more preferable. As the cationic starches are positively charged, they are easily attracted by the negatively charged cellulose fiber and fillers.
What is the use of cationic starch?
Cationic starches are widely used as wet end additives in paper making. They provide many benefits, classified into 4 categories: improvement of mechanical strength; better retention of fines and fillers; faster drainage; reduction of waste water pollution.
Is starch anionic or cationic?
The most common form of anionic starch is phosphorylated starch. It is prepared by treating starch with sodium tripolyphosphate.
How do you make cationic starch?
Cationic starch is produced by treating a slurry of partially swollen granules of starch with a reactive compound. An example of such a reagant is epoxypropyltrimethylammonium chloride. This reagant contains a quaternary nitrogen, yielding a positive charge that is independent of pH.
What is oxidised starch?
Oxidized starch is a modified starch. It is obtained by treatment of food starch in accordance with good manufacturing practice with sodium hypochlorite. Oxidation involves the deliberate production of carboxyl groups.
How starch is used in paper industry?
Starch is used as a flocculant and retention aid, as a bonding agent, as a surface size, as a binder for coatings and as an adhesive in corrugated board, laminated grades and other products.
What is anionic starch?
Oxidized (anionic) starches degrade much faster than conventional starch, i.e. they have improved biodegradability. This type of starch, however, is used on a much smaller scale than cationic starch but it is still an important starch-based additive.
What are starch based plastics?
Starch based plastics are complex blends of starch with compostable plastics such as PLA, PBAT, PBS, PCL and PHAs. Blending of starch with plastics improves water resistance, processing properties and mechanical properties. Starch based trays are not transparent.
What starch is used in papermaking?
The major starch sources are corn, potato, waxy maize, wheat, and tapioca. Refined starches are supplied in powder form or as slightly aggregated pearl starch. Unmodified (native) starch is rarely used in the paper industry, except as a binder for laminates and in the corrugating process.
How is oxidized starch beneficial to the food industry?
The oxidized starch is also becoming increasingly important in the food industry for its unique functional properties such as low viscosity, high stability, clarity, film forming, and binding properties.
What happens when starch is oxidized?
The oxidation of starch is usually carried out in order to reduce the viscosity of the starch in solution or dispersion. During the oxidation reaction, starch molecules- are broken down, yielding molecules having a decreased molecular weight. Oxidized starches have found many applications in industry.