Polymer stabilization antiozonants

Toxicology LD50 (oral, rat) 3580 mg/kg, (skin, rabbit) > 7940 mg/kg mod. toxic by ing. low toxicity by skin contact TSCA listed Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of NOx Uses Staining antioxidant/antiozonant for rubber polymer stabilizer Manuf./Distrib. Akrochem http //www.akrochem.com] Atofina http //WWW. atofinachemicais. com] Bayer/Fi ber, Addits., Rubber http //www.bayerus.com] Crompton/Uniroyal... 

It has been shown in the preceding sections that raw polymers are highly susceptible to degradative oxidation. The success of plastic materials, which find apphca-tions in practically any aspect of life, relies heavily on the performance of polymer stabilizers, 70% of which are used for polyolefins. According to their principal protection activity, common polymer stabilizers are conventionally classified as antioxidants, photoantioxidants, photostabilizers, metal deactivators, antiozonants, and heat stabilizers for PVC. 

Similar to Wingstay 100 and used mainly as an emulsion polymer stabilizer or where a liquid antiozonant is preferred. Very stable to acid coagulation of emulsion polymers. 

A number of amines and phenols are known to be effective stabilizers - for rubber (2, 20). They are capable of protecting unsaturated polymers from the attack of oxygen and ozone, but the effects of the stabilizers on antioxidation and antiozonization are not always the same —e.g., N,N -diphenyl-p-phenylenediamine (A) is an antioxidant, whereas jV,N -phenylcyclohexyl-p-phenylenediamine (B) is an antiozonant. 

It is easier to dissolve a stabilizer than to evaporate it [27]. The physical loss of stabilizers due to the leaching from polymer surfa< layers into liquids which come into contact is therefore more serious than volatilization. Problems arise mainly in systems where the degradation process has been concentrated at the surface layer and therefore an efficient surface protection of a polymer is mandatory. This phenomenon takes place mainly in photostabilization of plastics or antiozonant protection of rubbers. The surface loss of stabilizers is extremely serious in very thin profiles or products having a very high surface/mass ratio. 

Over half of the remaining market for products used in the processing of rubber is made up of antioxidants, antiozonants and stabilizers, either amino compounds or phenols. Aniline is used to manufacture vulcanization accelerators, antioxidants and antidegradants. Of the latter, several are A-substituted derivatives of p-phenylenediamine and octyl dipheny-lamine. Diphenylamines terminate free-radical reactions by donating the amino hydrogen, and are used to protect a wide range of polymers and elastomers. Many synthetic rubbers incorporate alkylated diphenylamine antioxidants. Other antioxidants include aryl amine resinous products from, e.g. condensation of aniline and acetone in the presence of... 

Used as a secondary accelerator with antioxidant, antiozonant, and stabilizing function in synthetic rubber and high polymer materials in the plastics and rubber industries. Mainly used in styrene-butadiene rubber (SBR), chloroprene rubber (CR), epichlorohydrin, and chlorosulfonated polyethylene rubber. Promotes heat-resistance of chlorosulfonated polyethylene rubber, EPDM and CSM and sunshine resistance of CR. 

Two types of stabilizers inhibit crack growth in rubbers microcrystalline waxes and alkylated phenylene diamines. A small quantity of the wax milled into a rubber will gradually diffuse to the surface where it will serve as a barrier impervious to ozone. A combination of wax and alkylated phenylene dicunine antiozonant is generally used for optimum protection. The exact function of antiozonant is still obscure but it is possible that it accelerates scission processes on the polymer surface producing a protective film of viscous products. 

Secondary aromatic amines are effective antioxidants in the protection of saturated hydrocarbon polymers (polyolefins) against autooxidation. Their role in the stabilization of unsaturated hydrocarbon polymers (rubbers) is more complex depending on their structure, they impart protection against autooxidation, metal catalyzed oxidation, flex-cracking, and ozonation. The understanding of antioxidant, antiflex-cracking and antiozonant processes together with involved mechanistic relations are of both scientific and economic interest. 

Macromolecular stabilizers are immobile in the polymer matrix [284], This is unfavourable for applications where surface concentration of stabilizers in thick-walled products should remain high. It was reported [34] that rubber-bound derivatives of PD provide only very poor antiozonant protection. Their antioxidant efficiency was only comparable with that of conventional HMW PD. This indicates that application of polymer-bound amines in rubbers has the prospect of exclusive long-term use in extracting media. 

Akrochem Antiozonant [Akrochem] Antiozonant protecting rubber polymers against heat, oxidation, and flexcracldng ccq>per, manganese inhibitor and SBR stabilizer. 

It has been known for a number of years that FD-MS is an effective analytical method for direct analysis of many rubber and plastic additives. Major components and impurities in commercial additives can be assessed quickly, and the FD-MS data can be used to help determine what (if any) additional analytical characterization is needed. Lattimer and Welch showed that FD-MS gives excellent molecular ion spectra for a number of polymer additives, including rubber accelerators (diWocarbamates, guanidines, benzothiazyl, and thiuram derivatives) antioxidants (hindered phenols, aromatic amines) p-phenylenediamine-based antiozonants, processing oils, and phthalate plasticizers. Zhu and Su characterized alkylphenol ethoxylate surfactants by FD-MS. Jackson et al. analyzed some plastic additives (hindered phenol antioxidants and a benzotriazole UV stabilizer) by FD-MS. ... 

Uses Antioxidant, antiozonant for petroleum-based and synthetic lubricants, rubbers, and plastics (PU) scorch retarder for CR in food-pkg. adhesives in closure-sealing gaskets for food containers antioxidant/stabilizer for food-grade polymers, pressure-sensitive adhesives antioxidant in food-contact rubber articles for... 

The antiozonants, N-(l,3-di-methylbutyl)-N -phenyl-p-phenylenediamine (6PPD) and the C7 and C5 alkyl-analogs were later introduced. In addition to their nse as antiozonants, p-phenylenediamines, primarily the more persistent mixed diaryl-derivatives, have replaced N-phenyl- 3-naphthylamine as antioxidants flex crack inhibitors and synthetic polymer antioxidant stabilizers. 

Antioxidants, antiozonants, light stabilizers, heat stabilizers, accelerators, etc., are generally polar compounds and have little affinity for non-polar polymers such as polyolefins. 

Because of its ability to investigate the stability of polymers, DSC is often used to evaluate the effectiveness of stabilisers (e.g. antioxidants and antiozonants) and to establish the energetics of their protective action. Examples of this type of application are the work carried out by Klein etal [84] and Cibulkova etal [85] who studied the effect ofp-phenylene diamine antidegradants with polyisoprene rubber, and Parra and Matos [86] who investigated the synergistic effects of a range of different antioxidants in natural rubber compounds. Burlett... 

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