In the field of polymer materials, organic peroxide is used as initiator of free radical polymerization, initiator of graft reaction, crosslinking agent of rubber and plastics, curing agent of unsaturated polyester and molecular weight and molecular weight distribution modifier in the preparation of spinning grade polypropylene. Organic peroxide is the source of free radicals in the following uses: Free radical polymerization and copolymerization initiator of ① vinyl and two monomer, ② curing agent of thermosetting resin, crosslinking agent of ③ elastomer and polyethylene.
Organic Peroxides In addition to the above polymer materials industry, organic peroxide as a light initiator and sensitizer used in the film industry, for photosensitive polymer materials, photosensitive resin, etc., also commonly used in the production of epoxy resin, medical materials, organic peroxide and pharmaceutical initiator, used to synthesize drug delivery matrix (such as microspheres, pellets, drug membranes), organic synthesis, organic peroxide is mainly used as oxidant and epoxide. In addition, Organic Peroxides organic peroxide should also be used in the disinfection of medical devices and foodstuffs, textiles, paper and other daily chemical industry bleach, bleaching agents, fungicides, cleaning agents and so on.
The decomposition temperature of an organic peroxide at an effective rate largely determines its use. Other important factors are cost, solubility, and safety. Organic Peroxides The efficiency and the types of free radicals generated, the necessity of refrigerated storage and freight, and the compatibility with production systems may affect the product and the ability to be activated. Organic peroxide can control a certain velocity decomposition at high temperature or at room temperature to generate reactive free radicals.
All organic peroxides are thermally unstable and are decomposed faster with increasing temperature. The commonly used quantitative method for the reactivity of organic peroxides is to determine the half-life, Organic Peroxides which is the time it takes to decompose a certain amount of peroxide at a given temperature to half its initial volume. Now, the half-life data of the commercial organic peroxide can be obtained from the computer floppy disk. Organic Peroxides Use a Computer menu program to select the appropriate peroxide for an aggregation or process condition.
These free radicals can be added to unsaturated vinyl monomers such as: styrene, vinyl chloride or methyl methacrylate to induce polymerization. Some free radicals also attack polymers such as PE to generate free radicals on the chain. When two such polymer free radicals are bonded together, Organic Peroxides a cross-linked structure is formed. Organic peroxides provide the most effective way to induce a free radical of polymerization. An organic peroxide is selected by a half-life temperature, or a mixture of two or more organic peroxides is used, and the polymerization of vinyl can be effectively carried out within a wider temperature range.
PVC is mainly made by suspension process. N-Ethyl carbonate and tert-butyl butyrate are good initiators, especially for the mixed use of new α-ester, a new decyl acid ester or a α-base. However, the use of α-can cause undesirable acetophenone odor in the resin. By using the new 1,-two methyl-hydroxy-butyl ester as a low-temperature initiator ingredient, can remove the odor of acetophenone in the resin. Organic Peroxides Other advantages of using this initiator are increased productivity and reduced adhesion on the wall of the reactor. As a result of improved processing and efficiency, the use of tert-amyl valerate to replace Azo initiator is now also used.
The resin of high solid acrylic coatings was used as initiator for the use of peracetic ester and peracetic acid. When the solid is 70% or higher, it is advisable to use tert-amyl oxygen ester and oxygen-containing ketone to obtain narrow molecular weight distribution and low solution viscosity. Organic Peroxides Also useful are resins such as tert-butyl acetate and 3, 3-Two (tert-amyl peroxide) butyrate to produce a lower monomer residue. In addition, organic peroxides with light stabilizer groups, such as hindered amines, are being actively developed to improve the performance of automotive coatings.
EPS is used in the production of EPs by suspension, usually with a mixture including benzoic acid and tert-butyl benzoate.
Using O-tert-amyl-O (ethyl cyclohexyl)-slip carbonate to replace tert-butyl formate, the residual styrene concentration can be shortened by less than 0. 1% response time required. Organic Peroxides Crystal PS and hips are usually prepared by continuous bulk polymerization, preferably using oxygen-reduction as initiator. Polyethylene is used as initiator in the production of LDPE and ethylene copolymers. Because the peroxide ester can provide a wide range of reactivity, and at high temperature, high pressure in the use of good solubility, is the best peroxide initiator. According to its efficiency, the most commonly used in peracetic esters is the over-bitter tert-butyl ester. Other varieties, in descending order of use, were the tert-butyl ester, tert-butyl acetate and tert-butyl benzoate. If a stronger reaction activity is needed, the corresponding tert-amyl oxygen ester can be used.
As a means to improve the film strength in the extruder, it is more and more interesting to reduce LLDPE melt flow with organic peroxide. Double alkyl peroxide is often used when higher processing temperatures are required.
The organic peroxide can be used for cracking polypropylene to obtain narrow molecular weight distribution and increase fluidity. Select 2, 5-two methyl-2, 5-di-tert-butyl-N-hexane in the case of performance and FDA requirements. Thermosetting polyester can be made by curing unsaturated polyester alkyd resins with organic peroxide and monomer solutions such as styrene. Many curing at room temperature, Organic Peroxides in the resin mixed with activator or promoter, so that a certain peroxide decomposition to form free radicals, thus triggering curing.