Elastomers heat stabilizers

Sukano OnCap BIO impact T Sukano PLA Linear elastomer Heat stability FDA approved Tear resistant Transparent FDA approved, 4-8 Films, cut For injection molded resins Transparent applications For a variety of processing equipment For standard film [140, 141]... 

Nickel dialkyldithiocarbamates stabili2e vulcani2ates of epichlorhydrinethylene oxide against heat aging (178). Nickel dibutyldithiocarbamate [56377-13-0] is used as an oxidation inhibitor in synthetic elastomers. Nickel chelates of substituted acetylacetonates are flame retardants for epoxy resins (179). Nickel dicycloalkyldithiophosphinates have been proposed as flame-retardant additives for polystyrene (180—182) (see Flame retardants Heat stabilizers). 

Organophosphoms compounds, primarily phosphonic acids, are used as sequestrants, scale inhibitors, deflocculants, or ion-control agents in oil wells, cooling-tower waters, and boiler-feed waters. Organophosphates are also used as plasticizers and flame retardants in plastics and elastomers, which accounted for 22% of PCl consumed. Phosphites, in conjunction with Hquid mixed metals, such as calcium—zinc and barium—cadmium heat stabilizers, function as antioxidants and stabilizer adjutants. In 1992, such phosphoms-based chemicals amounted to slightly more than 6% of all such plastic additives and represented 8500 t of phosphoms. Because PVC production is expected to increase, the use of phosphoms additive should increase 3% aimually through 1999. 

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. 

P.R.149 also lends color to cast resins made from materials such as unsaturated polyester or methacrylic acid methylester, which are polymerized with peroxide catalysts. P.R.149 is equally lightfast in these media. In polycarbonate, the pigment tolerates exposure to more than 320°C. This is an asset in view of the fact that polycarbonate shows high melt viscosity and is thus processed at up to 340°C. The list of applications also includes other media, such as PUR foams and elastomers, for which P.R.149 is recommended because of its good heat stability and its coloristic properties. 

The compositions consist of a heat-plastified mixture of an ethylene homopolymer or copolymer, about 3 to 30 pbw of an elastomer, a stability control agent, which is a partial ester of a long chain fatty acid with a polyol, higher allyl amine, fatty acid amide or olefinically unsaturated carboxylic acid copolymer, and a hydrocarbon blowing agent having from 1 to 6 carbon atoms and a boiling point between -175 and 50C. 

The major general purpose rubbers are natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and ethylene-propylene rubber. These rubbers are used in tires, mechanical goods, and similar applications. Specialty elastomers provide unique properties such as oil resistance or extreme heat stability. Although this differentiation is rather arbitrary, it tends also to classify the polymers according to volumes used. Styrene-butadiene rubber, butadiene rubber, and ethylene-propylene rubber account for 78 percent of all synthetic rubber consumed. 

Most commercial fluorocarbon elastomers have brittle points between -25°C (-13°F) and -40°C (-40°F). The low-temperature flexibility depends on the chemical structure of the polymer and cannot be improved markedly by compounding. The use of plasticizers may help somewhat, but at a cost of reduced heat stability and worsened aging. Peroxide-curable polymers may be blended with fluorosilicones, but such blends exhibit considerably lower high-temperature stability and solvent resistance and are considerably more expensive than the pure fluorocarbon polymer. Viton GLT is a product with a low brittle point of -51°C (-59°F) [48]. Tecnoflon for containing a stable fluorinated amide plasticizer reportedly exhibits improved low-temperature hardness, brittle point, and compression set without sacrificing physical properties [66]. Low-temperature characteristics of selected fluorocarbon elastomers are listed in Table 5.13 [9]. 

Inorganic additives for rubber compounds also include materials that enhance performance under various accelerated stress conditions. Zinc oxide is an effective heat stabilizer for some types of elastomers. Iron oxide, lead compounds, barium salts, and specially treated clays, such as kaolinite, add performance margin in wet aging conditions. 

Ethanox 376 is a stabilizer that provides heat stability by preventing thermo-oxidative degradation during processing and service life. It provides compatibility with resins and extraction resistance. It can be applied in polyolefins, such as polyethylene, polypropylene, polybutene-1 and other polymers such as engineering plastics, styrenes, polyurethanes, saturated and unsaturated elastomers, styrenics, rubber modified styrenics, segmented block copolymers, and PVC. 

Non-discoloring, sulfur containing phenolic antioxidant and stabilizer that provides long-term heat stability by preventing thermo-oxidative degradation. Used for the process stabilization of polyethylene wire and cable resins for polyethylene during extruder compounding. Can also be applied in styrenic polymers, polypropylene, elastomers such as EPDM and SBR and for carboxylated SBR latex, polybutadiene rubber and polyisopropene rubber. 

Since ABS degrades by the simultaneous action of high temperamre and atmospheric oxygen, the only products that may be used for extmsion and thermoforming are those with exceptional heat stability. Both ABS/elastomer blend series (Terluran ), those with butylacrylate elastomer, BA, and with polybutadiene, PB, satisfy this requirement. The ABS/BA series is especially suitable for critical pale shades. Vented extmders are preferred with L/D = 25-30 and compression ratio of 3 in both sections. 

Uses Heat stabilizer for PVC, ABS, polyolefins, elastomers, acrylics, adhesives, nylon, PC, PU, PS, coalings, PET food pkg. adhesives, coatings, nibber articles, polymers, closures with sealing gaskets for food containers... 

Chem. Descrip. Trisnonylphenyl phosphite CAS 26523-78-4 EINECS/ELINCS 247-759-6 Uses Processing stabilizer, heat stabilizer for polyolefins, acrylics, adhesives, elastomers, nylon, PC, PU, PS, PVC, coatings, ABS, and PET, food-contact pkg., m lcal devices, color-critical polyolefins, sfyrene block copolymers... 

Features Paintable greater heat stability in release film reactive with sulfur and peroxide cured elastomers Properties Straw clear to hazy liq., mild sulfur odor sol. In aliphatic and aromatic hydrocarbons insol. in water sp.gr. 1.00 dens. 8.0 Ib/gal vise. 1000-3000 cSt b.p. > 600 F flash pt. (PMCC) > 149 C 100% act. Toxicology May cause temporary eye discomfort, mild redness, dryness on direct contact no irritation to respiratoiy passages on acute inh. swallowing Ig. amts, may cause digestive discomfort TSCA listed Hazardous Ingredients None... 

CAS 6683-19-8 EINECS/ELINCS 229-722-6 Uses Antioxidant, heat stabilizer for org. and polymeric materials, polyolefin, elastomer, acetal, acrylic, PET, PU, PMMA, PVC, food-contact adhesives/coatings/paper/polymers, petrol, prods., coatings Features Nondiscoloring, nonstaining U.S. patents3,285,855 and 3,644, 482... 

CAS 3896-11-5 EINECS/ELINCS 223-445-4 Uses UVabsorber tabilizerforABS, PE, PP, PS, PU, PVC, unsat. polyester resins and coatings, other polymers, elastomers, food pkg. heat stabilizing effect in PVC Features Improves weathering resist. 

Chem. Descrip. Polytetrafluoroethylene CAS 9002-84-0 EINECS/ELINCS 204-126-9 Uses Lubricant, antiwear agent, antisticking agent, conosion inhibitor, heat stabilizer in elastomers or plastics dry-film lubricant improves release, mar resist., slip, chem. resist., weatherability, moisture repellent chars, in paints/coatings, printing inks (for scuff resist.), oils and greases Features UV resist. 

Uses Heat stabilizer for vinyl resins, lacquers, elastomers lubricant for flexible vinyls catalyst for PU foam and silicone elastomers catalyst forfood-contact PU resins and PU resins in food-pkg. adhesives plasticizer... 

PCL is commonly used in the manufacture of polyurethanes because of its imparting good water, oil, solvent, and chlorine resistance to the polyurethane produced. In 1934, Carothers et al. [103] prepared epsilon-caprolactone for the first time. Under the condition of heat epsilon-caprolactone is converted to a polyester of high molecular weight. The 1965, Magnus [104] published details of his study of effects of components and varying -NCO/-OH or -NCO/-NH2 group ratio on the low-temperature properties, hydrolytic and heat stability, and solvent and chemical resistance of the polyurethane elastomers. It was found that... 

TPO materials are defined as compounds (mixtures) of various polyolefin polymers, semicrystalline thermoplastics, and amorphous elastomers. Most TPOs are composed of polypropylene and a copolymer of ethylene and propylene called ethylene—propylene rubber (EPR) [2]. A common rubber of this type is called ethylene propylene diene monomer rubber (EPDM), which has a small amount of a third monomer, a diene (two carbon-carbon double bonds in it). The diene monomer leaves a small amount of unsaturation in the polymer chain that can be used for sulfur cross-linking. Like most TPEs, TPO products are composed of hard and soft segments. TPO compounds include fillers, reinforcements, lubricants, heat stabilizers, antioxidants, UV stabilizers, colorants, and processing aids. They are characterized by high impact strength, low density, and good chemical resistance they are used when durability and reliability are primary concerns. 

Polyamide thermoplastic elastomers are characterized by their high service temperature under load, good heat aging, and solvent resistance. They retain serviceable properties >120 h 302°F (150°C) without adding heat stabilizers. Addition of a heat stabilizer increases... 

Recently, impact modifiers have been developed for plastics other than PVC. Polybutylene and other olefinic thermoplastic elastomers, for example, are being used to enhance the processability, toughness, and heat stability of polypropylene film. Hydroxy-terminated polyethers are being used to increase the impact resistance of polystyrene. Other conunon applications are polycarbonate, polyurethane, thermoplastic polyester, epoxy, and polysulfone. 

Recent developments include systems with better colour fidelity and handling properties. Dover s Doverphos HiPure 4 and 4-HR are high-purity tris-nonylphenyl phosphite (TNPP) processing and heat stabilizers, claimed to reduce overall costs. With 0.1% residual nonyl phenol, they are FDA-approved for food-contact applications and also used in medicals, colour-critical polyolefins, and styrenic block copolymers. They are effective also in acrylics, elastomers, nylon, polycarbonate, polyurethanes, polystyrene. PVC. ABS, and PET. 

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