Sodium perborate (PBS) mumbai is a white, odorless, water-soluble chemical compound with the chemical formula NaBO3. It crystallizes as the monohydrate, NaBO3·H2O, trihydrate, NaBO3·3H2O and tetrahydrate, NaBO3·4H2O.The monohydrate and tetrahydrate are the commercially important forms. The elementary structural unit of sodium perborates is a dimer anion B2O4(OH)42−, in which two boron atoms are joined by two peroxo bridges in a chair-shaped 6-membered ring, and the simplistic NaBO3·nH2O-type formulas are just a convenient way to express the average chemical composition.
Preparation and chemistry
Sodium perborate is manufactured by reaction of disodium tetraborate pentahydrate, hydrogen peroxide, and sodium hydroxide. The monohydrate form dissolves better than the tetrahydrate and has higher heat stability; it is prepared by heating the tetrahydrate. Sodium perborate undergoes hydrolysis in contact with water, producing hydrogen peroxide and borate.
Unlike sodium percarbonate mumbai and perphosphate, the sodium perborate is not simply an adduct with hydrogen peroxide, and it does not contain an individual BO3− ion. Rather, there is a cyclic dimer anion B2O4(OH)42−, in which two boron atoms are joined by two peroxo bridges in a chair-shaped 6-membered ring. This makes the substance more stable, and safer for handling and storage. The formula of the sodium salt is thus Na2H4B2O8.
Uses Of Sodium Perborate
Sodium perborate monohydrate (synonyms: sodium peroxyborate, sodium peroxoborate, PB1) is similar to sodium percarbonate as a famous oxygen bleach agent. Sodium perborate offers many of the functional benefits as liquid hydrogen peroxide in a stable solid form. The oxidative power of sodium perborate improves the cleaning, bleaching, stain removal and deodorizing performance of powder detergent formulations, all fabric dry bleaches, denture cleaners, automatic dishwasher detergents and various institutional and industrial laundry products.
Sodium perborate monohydrate is prepared by dehydrating sodium perborate tetrahydrate. The monohydrated sodium perborate is essentially showing three advantages in comparison with the tetrahydrated sodium perborate: higher content of available oxygen, higher heat stability and higher dissolution rate into water. It provides a high available oxygen content equivalent to 32% hydrogen peroxide – 50% more active oxygen than the same weight of sodium perborate tetrahydrate. Sodium perborate releases nascent oxygen at elevated temperatures, it is a stable, solid source of active oxygen.
Sodium perborate will decompose in the environment to natural borate. Although boron is an essential micronutrient for healthy growth of plants, it can be harmful to boron sensitive plants in higher quantities. Care should be taken to minimize the amount of borate product released to the environment.
Sodium perborate mumbai serves as a source of active oxygen in many detergents, laundry detergents, cleaning products, and laundry bleaches. It is also present in some tooth bleaching formulas. It is used as a bleaching agent for internal bleaching of a non vital root treated tooth. The sodium perborate is placed inside the tooth and left in place for an extended period of time to allow it to diffuse into the tooth and bleach stains from the inside out. It has antiseptic properties and can act as a disinfectant. It is also used as a “disappearing” preservative in some brands of eye drops.
Sodium perborate mumbai is a less aggressive bleach than sodium hypochlorite, causing less degradation to dyes and textiles. Borates also have some non-oxidative bleaching properties.
Sodium perborate mumbai releases oxygen rapidly at temperatures over 60 °C. To make it active at lower temperatures (40–60 °C), it has to be mixed with a suitable activator, typically tetraacetylethylenediamine (TAED).