Introduction
Di benzoyl peroxide is also called Benzoyl Peroxide, other name like initiator BPO is also available.
It is an organic compound with the chemical name C14H10O4. It is a white moldable powder at room temperature with a slight bitter almond aroma. It can dissolve benzene, chloroform, ether, microemulsion and water. It is mainly used as polystyrene and water. It is a chemical polymerization initiator for polystyrene, non-styrene polyesters, acetate, etc. It can also be used as a cross-linking agent for polyethylene and a rubberizing agent for wood.
On October 27, 2017, the Santa Claus International Agency for Research on Cancer released a preliminary reference list of index objects. Benzoyl Peroxide is included in the list of Category 3 index substances.
Purposes and applications
Dibenzoyl peroxide is the most widely used initiator for polymerization reactions. It is mainly used for solvent polymerization of PVC, polyacrylonitrile, acrylate, and vinyl acetate, and graft polymerization of chloroprene rubber, SBS and methyl methacrylate. Unsaturated polyester resin curing, initiator and cross-linking agent for organic glass adhesives, etc. In the rubber industry, it is used as vulcanizing agent and cross-linking agent for silicone rubber and fluorine rubber. It can also be used as a bleaching agent and oxidant in chemical production. Dibenzoyl peroxide has a whitening effect on wheat flour. On February 11, 2011, my country's Ministry of Health and other six ministries and commissions issued a notice that starting from May 1, 2011, it is prohibited to add benzoyl peroxide, Calcium peroxide, food additive manufacturers are not allowed to produce and sell food additives calcium peroxide and benzoyl peroxide.
A. Initiators,crosslinker
Also known as free radical initiators, they refer to a class of compounds that are easily decomposed into free radicals (i.e. primary free radicals) by heat. They can be used to initiate free radical polymerization and copolymerization reactions of alkene and diene monomers, as well as crosslinking curing and polymer crosslinking reactions of unsaturated polyesters
Initiators are generally compounds with weak bonds and easily decomposable active species, among which covalent bonds have two forms: homolytic and heterolytic. Also known as a starter. Chemical carcinogens that can transform normal cells into dominant tumor cells. Initiators have the following characteristics: they are carcinogenic and must be administered before the growth promoter. They can produce their effects with a single contact or exposure, and their effects can accumulate and are irreversible, without a threshold dose; Can generate electrophilic substances that covalently bind to cellular macromolecules (DNA), with the vast majority being mutagenic. For example, trans-4-acetamiprid is used as an initiator.
Initiators are substances that can initiate polymerization reactions of monomers. Unsaturated monomer polymerization active centers include free radical, anionic, cationic, and coordination compounds. The most commonly used type in the adhesive industry is the free radical type, which exhibits unique chemical activity. Under the action of heat or light, covalent bond cleavage occurs to generate two free radicals, which can trigger polymerization reactions.
Initiators play a very important role in the research and production of adhesives and sealants. Acrylate solvent polymerization is used to prepare pressure sensitive adhesive, vinyl acetate solvent polymerization is used to manufacture construction adhesive and construction sealant, synthesis of styrene acrylic lotion, ethylene propylene lotion, VAE lotion, styrene butadiene latex, neoprene latex, white latex, graft neoprene adhesive, sBs graft adhesive, unsaturated polyester resin cross-linking and curing, anaerobic adhesive curing, fast curing acrylate structural adhesive curing, etc. must use initiators. Initiators can directly affect the smooth progress of the polymerization reaction process, as well as the polymerization reaction rate and the storage period of the product.
As an initiator, benzoyl peroxide can be used in the production of the following products
- Medicinal high viscosity acrylic resin
- o-Chlorobenzaldehyde(OCBA)
- Polymerized methyl methacrylate
- Unsaturated resin curing
- Polycarboxylic acid new efficient solid water reducer
- Silane crosslinked EVA modified LLDPE material
- cation exchange membrane
- Polyethylene, polypropylene, polyvinyl chloride, PMMA,polystyrene,etc. Polymer
- Methyl methacrylate (MMA) styrene (ST) copolymer beads
- PVC,Solvent polymerization of polyacrylonitrile, acrylic ester, and vinyl acetate, graft polymerization of chloroprene rubber, SBS, and methyl methacrylate. Curing of unsaturated polyester resin, initiator and crosslinking agent for organic glass adhesives, etc
A1.PVC Sysnthesis Process.
The synthesis of PVC resin includes the following methods：
1.Low temperature synthesis method
According to the mechanism of vinyl chloride polymerization reaction, the average polymerization degree of PVC resin is only a single parameter function of polymerization temperature. By controlling the polymerization temperature, PVC resin with the desired degree of polymerization can be obtained. The lower the temperature, the higher the degree of polymerization.
2.Chain extender synthesis method
Chain extenders refer to substances containing two or more di (poly) ene structures that can react with free radicals. Adding a small amount of chain extender to the polymerization system and copolymerizing with vinyl chloride monomer can increase the molecular weight of the product.
Chloroethylene, chain extenders, initiators, dispersants, etc. are added to the suspension polymerization system after the reaction pressure drops to the set value. After stirring evenly, the material is discharged, and unreacted vinyl chloride monomers in the slurry are removed by stripping. The resin is sent to the drying system for drying, and finally obtain finished product packaging.
A2.Synthesis of Polyacrylonitrile
Suspension free radical copolymerization in aqueous phase.
Sometimes azobisisobutyronitrile can be used instead.
A3.Acrylic ester, vinyl acetate solvent polymerization,Graft polymerization of chloroprene rubber, SBS and methyl methacrylate
B.Vulcanizing agent, crosslinking agent
Silicone rubber and fluororubber.
C.Bleach whitening agent
Benzoyl peroxide has a whitening effect on wheat flour.
It is prohibited to add benzoyl peroxide and calcium peroxide in flour production, and food additive production enterprises are not allowed to produce or sell food additives such as calcium peroxide and benzoyl peroxide since 2011 in China.