Benzoyl peroxide, curing agent

Aliphatic or aromatic peroxide curing agents can also be used, by reactions with vinyl side chains or even saturated alkyl groups. Specihc peroxides are chosen on the basis of their decomposition temperatures, and the reaction products they leave behind after the curing process is complete. Some peroxides used are Mv(2,4-dichloroben-zoybperoxide, benzoyl peroxide, dicumyl peroxide, and di-t-butyl peroxide.83-86... 

Initially, the co-agents were mixed with PVDF and FMVQ separately and the mixtures were subjected to mild irradiation. Solubility tests indicated no cross-hnking during this operation. The polymeric components were then mixed in the presence of CaO/MgO in a Brabender plasticorder at a rotor speed of 60 rpm at 160°C. Subsequently, the temperature was lowered to 130°C and a 0.2% benzoyl peroxide paste was added. Mixing was continued for 10 more minutes. Cure characteristics... 

As an example, a foam prepared from III, alumina trihydrate as a filler, benzoyl peroxide as a curing agent, and azobis formamide as a blowing agent, leads to a material with an oxygen index of 48, a long-term stability to at least 150 °C, and a smoke density about one fifth that of a commercial foam [284]. 

Benzoyl peroxide is used as an initiator for polymerization of acrylates (including dental cements and restoratives) and other polymers as a bleaching agent for flour, fats, oils, waxes and milk used in the preparation of certain cheeses in pharmaceuticals for the topical treatment of acne in rubber curing and as a finishing agent for some acetate yams (Anon., 1984 Lewis, 1993 Medical Economics Co., 1996 United States Food and Dmg Administration, 1997). 

Molar excess of epoxynovolak resin was reacted with DDS highly branched aminoepoxide resin was thus obtained. The resin was then mixed with a non-modified epoxide resin, BPA/DC-BMI copolymer, benzoyl peroxide and /V-(3,4-dichloro-phenyI)-Ar, Ar -dimethyIurea (curing agent for the epoxy component) [116]. 

Heat-cured denture base materials were introduced into dental use in 1937. These materials are prepared from a powder-liquid slurry. The liquid is methyl methacrylate to which are added a plasticizer, crosslinking agent and inhibitor. The powder is poly(methyl methacrylate) containing approximately one percent initiator, usually benzoyl peroxide. By subjecting this slurry to elevated temperature (about 75°C to 100°C) for one or more hours depending on the temperature employed, sufficient free radicals are produced from the initiator to yield a satisfactory denture. Other initiators have been proposed. 

The most important crosslinking agent for pressureless hot air vulcanization of silicone rubber is DClBP(Bis-2,4-dichloro-benzoyl-peroxide) (Fig. 14). It generates decomposition products, which are removed in a post-curing process with air blowing. This product provides the advantage of a fast cure rate and bubble-free cured transparent rubber. 

Cure Agents and Cure Accelerators Crosslinking the system Benzoyl peroxide for plastics, zinc oxide and sulfur for rubbers... 

Other examples of this phenomenon include residual crosslinking agents from partially cured duroplastics, formaldehyde from phenolic resin, amines in epoxy resins, and benzoyl peroxide from unsaturated polyesters. Section 5.3 in chapter Processing (Primary Forming) of Plastics into Structural Components addresses the nitrosamine in elastomers. 

Benzoyl peroxide (1924) (dibenzoyl peroxide, DBF) n. A catalyst employed in the polymerization of polystyrene, styrene, vinyl, and acrylic resins. It is also a curing agent for polyester and silicone resins, usually used together with an accelerator such as dimethylaniline. It can be dispersed in diluents or plasticizers to diminish the explosion hazard associated with the dry product. Its natural state is colorless crystals of mp of 103°C. Odian GC (2004) Principles of polymerization. John Wiley and Sons Inc., New York. 

Catalyst (curing agent) Initiate the curing reaction at elevated temperature Benzoyl peroxide (e.g., tertiary butyl perbenzoate)... 

---