Rubber stabilizers, properties

Chem. Descrip. Triphenyl phosphite CAS 101-02-0 EINECS/ELINCS 202-908-4 Uses Costabilizer for PVC and other polymers such as PP vise, modifier, reactive diluent for a variety of resin systems, esp. epoxies antioxidant for syn. rubbers, butyrates flame retardant for PU foams in transesterification reactions lubricant oil additive chem. intermediate for prod, of other phosphite esters and phosphonates Features Improves adhesion, elec, props., dimensional stability Properties Colorless mobile liq. 10% P Albrite Tributyl Phosphate [Huntsman Surf. Sciences]... 

Uses Resin extender, plasticizer improving water, chem., oil, and gas resist, in traffic paints, protective coatings EP agent in metalworking fluids flame retardant for resins, air filters, plasticized PVC, rubber incl. neoprene, PU, textiles, paints, adhesives Features Good color low vise. exc. stability Properties Gardner 1 color sol. in most org. soivs. insol. in water, lower alcohols, glycols sp.qr. 1.180 dens. 9.6 Ib/qal vise. 2.5 poises flash pt. (COC) >400 F 45% Cl Paroil 50 [Dover]... 

At the present time, attempts are being made to expand the circle of amines for practical use. Thus, it was shown in [27] and [28] that certain secondary amines of the thiophene series, the S3mthesis of which is more accessible than that of amines of the benzene series, possess good stabilizing properties (as applied to rubbers and polyolefins). Moreover, the replacement of the phenyl radical in the molecule of phenyl-/3-naphthylamine by the thenyl radical in a number of cases exerts a more favorable influence on the effectiveness of the amine. For example, 2-thenyl-/3-naphthylamine is not inferior to neozone D ineffectiveness, and sometimes surpasses it. The effectiveness of the amine is substantially increased if a hydroxyl group is introduced into the molecule. The introduction of an OH group into the molecule of diphenylamine [29] increases the effectiveness of the latter. An analogous picture is observed with amines of the thiophene series [28]. 

Uses Intermediate for mfg. of soaps, emulsions, ethoxylates, buffing compds., lubricants activator, dispersant, stabilizer, internal lubricant for rubber compding. Properties Flakes acid no. 205-211 iodine no. 3 max. sapon. no. 205-212 100% cone. 

Uses Dispersant for pigments, carbon bik., dyestuffs stabilizer for dispersions and emulsions dispersant for rubber syntheses, processing of rubber latexes Properties Liq. water-misc. 45% cone. 

Uses Emulsifier, solubilizer, wetting agent, thickener in textiles, cosmetics, hand cleaners spreading agents vise, stabilizer, emulsifier for rubber latexes Properties Yel. liq. bland odor water-sol, sp.gr. 0.99 acid no, > 6 100% cone. Nonisol 210 [Ciba Spec, Chems./Plastic Addit.j Chem. Descrip. PEG-8 dioleate Ionic Nature Nonionic CAS 9005-07-6... 

Nitrile mbber finds broad application in industry because of its excellent resistance to oil and chemicals, its good flexibility at low temperatures, high abrasion and heat resistance (up to 120°C), and good mechanical properties. Nitrile mbber consists of butadiene—acrylonitrile copolymers with an acrylonitrile content ranging from 15 to 45% (see Elastomers, SYNTHETIC, NITRILE RUBBER). In addition to the traditional applications of nitrile mbber for hoses, gaskets, seals, and oil well equipment, new applications have emerged with the development of nitrile mbber blends with poly(vinyl chloride) (PVC). These blends combine the chemical resistance and low temperature flexibility characteristics of nitrile mbber with the stability and ozone resistance of PVC. This has greatly expanded the use of nitrile mbber in outdoor applications for hoses, belts, and cable jackets, where ozone resistance is necessary. 

Cure Characteristics. Methods of natural rubber production and raw material properties vary from factory to factory and area to area. Consequentiy, the cure characteristics of natural mbber can vary, even within a particular grade. Factors such as maturation, method and pH of coagulation, preservatives, dry mbber content and viscosity-stabilizing agents, eg, hydroxylamine-neutral sulfate, influence the cure characteristics of natural mbber. Therefore the consistency of cure for different grades of mbber is determined from compounds mixed to the ACSl formulation (27). The ACSl formulation is as follows natural mbber, 100 stearic acid, 0.5 zinc oxide, 6.0 sulfur, 3.5 and 2-mercaptobenzothiazole (MBT), 0.5. 

Rubber. The mbber industry consumes finely ground metallic selenium and Selenac (selenium diethyl dithiocarbamate, R. T. Vanderbilt). Both are used with natural mbber and styrene—butadiene mbber (SBR) to increase the rate of vulcanization and improve the aging and mechanical properties of sulfudess and low sulfur stocks. Selenac is also used as an accelerator in butyl mbber and as an activator for other types of accelerators, eg, thiazoles (see Rubber chemicals). Selenium compounds are useflil as antioxidants (qv), uv stabilizers, (qv), bonding agents, carbon black activators, and polymerization additives. Selenac improves the adhesion of polyester fibers to mbber. 

In attempts to further improve the stability of fluorine-containing elastomers Du Pont developed a polymer with no C—H groups. This material is a terpolymer of tetrafluoroethylene, perfluoro(methyl vinyl ether) and, in small amounts, a cure site monomer of undisclosed composition. Marketed as Kalrez in 1975 the polymer withstands air oxidation up to 290-315°C and has an extremely low volume swell in a wide range of solvents, properties unmatched by any other commercial fluoroelastomer. This rubber is, however, very expensive, about 20 times the cost of the FKM rubbers and quoted at 1500/kg in 1990, and production is only of the order of 1 t.p.a. In 1992 Du Pont offered a material costing about 75% as much as Kalrez and marketed as Zalak. Structurally, it differs mainly from Kalrez in the choice of cure-site monomer. 

The rubber has a very low of -68°C, excellent hydrolytic stability and excellent resistance to ozone, solvents and acids. In addition the rubber does not bum even in an oxidising atmosphere. Although its properties are virtually unchanged in the range -75 to + 120°C it does not possess the heat resistance of other fluoroelastomers. This polymer was marketed by Firestone in the mid-1970s as PNF rubber, but in 1983 the Ethyl Corporation obtained exclusive rights to the Firestone patents and the polymer is now marketed as Eypel F. 

The important properties of the rubbers are their temperature stability, retention of elasticity at low temperatures and good electrical properties. They are much more expensive than the conventional rubbers (e.g. natural rubber and SBR) and have inferior mechanical properties at room temperature. 

The early 1980s saw considerable interest in a new form of silicone materials, namely the liquid silicone mbbers. These may be considered as a development from the addition-cured RTV silicone rubbers but with a better pot life and improved physical properties, including heat stability similar to that of conventional peroxide-cured elastomers. The ability to process such liquid raw materials leads to a number of economic benefits such as lower production costs, increased ouput and reduced capital investment compared with more conventional rubbers. Liquid silicone rubbers are low-viscosity materials which range from a flow consistency to a paste consistency. They are usually supplied as a two-pack system which requires simple blending before use. The materials cure rapidly above 110°C and when injection moulded at high temperatures (200-250°C) cure times as low as a few seconds are possible for small parts. Because of the rapid mould filling, scorch is rarely a problem and, furthermore, post-curing is usually unnecessary. 

Forms of BR and polyisobutylene. The properties of butyl rubber and polyisobutylene depend on their moleeular weight, degree of unsaturation, nature of the stabilizer incorporated during manufacture and, in some cases, chemical modification. It is common to produce halogenated forms of butyl rubber to increase polarity and to provide a reactive site for alternate cure mechanisms [6],... 

Butyl latices are prepared by emulsification of butyl rubber. Butyl latex has excellent mechanical, chemical and freeze-thaw stability, and when dried it shows the typical properties of butyl rubber [7]. 

With rubber base adhesives, it is necessary to prevent their properties from changing during service life. Oxidative changes induced by thermal, ozone exposure and UV light can dramatically affect service life of rubber base adhesives. More precisely, the rubber and the resin are quite susceptible to oxidative degradation. Environmental and physical factors exert detrimental effects on rubber base adhesive performance. These effects can be mitigated by the incorporation of low levels of stabilizers during the fabrication process of the adhesive. 

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