Mooney viscosity

Poljraer Specific gravity Mooney viscosity Tensde strength, MPa Elongation, % Ash, % Acetone extract, %... 

Filler loading Volume, parts Mooney viscosity Optimum cure (at 141°C), min Modulus (at 300%), MPa Tensde strength, MPa Elongation, % Hardness, Shore A NBS abrasion (ASTMD1630) Rebound, %... 

Type Monomer ratio styrene/butadiene Mooney viscosity, ML-4 SoHds, wt % pH Emulsifier ... 

High stmcture blacks ia unvulcanized mbber give higher Mooney viscosities, lower die swell, faster extmsion rates, and better and more rapid dispersion after iacorporation. In vulcanized mbber higher modulus is obtained. High stmcture blacks give lower bulk densities and high vehicle demand ia paint systems. 

An antioxidant such as phenyl-(3-naphth larnine, was then added to the latex (1.25 parts) prior to coagulation by salt—acid mixtures and drying of the mbber cmmb, which was compressed into 34-kg bales. The SBR produced by this recipe had a Mooney viscosity of about 50 and a number-average molecular weight M of 100,000—200,000. 

Ziegler-Natta type catalysts can generate a very high cis-1,4 stmcture (>90%), which is the choice polymer for tires. It is made to specifications similar to SBR, ie, molecular weight average of 100,000—200,000, Mooney viscosity 50, and od-extended. Lithium catalysts on the other hand yield variable chain stmctures, depending on the solvent used, ie, mixed stmctures of cis-1,4 and trans-1,4 and 1,2. These polymers are generally ia the lower... 

Molecular Structure. The chain stmcture is as shown in Table 1 and molecular weights of 300,000—500,000 are achieved. The Mooney viscosities are in the range of 40—70 leading to a soft elastomer, which requires carbon black reinforcement for higher modulus. 

Polymerization. Emulsion polymerization is used, but the latex is too unstable for use and all the latex is coagulated to dry mbber. The molecular weight range is 100,000—200,000 with a Mooney viscosity of 50—70. 

The uncured property most often used for CSM in dry appHcations is Mooney viscosity, alow shear bulk viscosity (ca 1.6 ) determined at 100°C. 

Mooney viscosity is a mbber industry standard used to predict raw mbber and compound processibiUty, ie, mixing, extmsion, mol ding, etc. 

The bulk viscosity control parameter for CSM, as with other elastomers, is molecular weight M and molecular-weight distribution (MWD). Mooney viscosity for CSM is determined by selection of the polyethylene precursor. 

As the polymer molecules form and dissociate from the catalyst, they remain ia solution. The viscosity of the solution increases with increasing polymer concentration. The practical upper limit of solution viscosity is dictated by considerations of heat transfer, mass transfer, and fluid flow. At a mbber soflds concentration of 8—10%, a further increase in the solution viscosity becomes impractical, and the polymerisation is stopped hy killing the catalyst. This is usually done by vigorously stirring the solution with water. If this is not done quickly, the unkilled catalyst continues to react, leading to uncontrolled side reactions, resulting in an increase in Mooney viscosity called Mooney Jumping. 

Moonej Viscosity. This is a measurement of the viscosity of the polymer that is commonly used ia the mbber iadustry. Mooney viscosity values typically range from 25 to 100. Mooney viscosity generally relates to polymer molecular weight, with the lower Mooney viscosity polymers providing improved flow and processiag characteristics and the higher Mooney NBRs providing improved physical properties. 

Mooney viscosity, MLl -specific gravity refractive index... 

Specifications for soHd i7j -l,4-polyisoprenes are shown in Table 5 and include analyses for volatile matter, extractables, ash, and Mooney viscosity at 100°C. Standard method ASTM D1416 includes chemical analysis methods for volatile matter, extractables, and total ash, while ASTM D1646 includes Mooney viscosity (82). The Monsanto rheometer data for vulcanizates prepared by a standard recipe may also be specified. This formulation for vulcanizate (ASTM D3403) is mixed in a Banbury mixer in two passes with all but sulfur and accelerator added in first pass ... 

Other polymers used in the PSA industry include synthetic polyisoprenes and polybutadienes, styrene-butadiene rubbers, butadiene-acrylonitrile rubbers, polychloroprenes, and some polyisobutylenes. With the exception of pure polyisobutylenes, these polymer backbones retain some unsaturation, which makes them susceptible to oxidation and UV degradation. The rubbers require compounding with tackifiers and, if desired, plasticizers or oils to make them tacky. To improve performance and to make them more processible, diene-based polymers are typically compounded with additional stabilizers, chemical crosslinkers, and solvents for coating. Emulsion polymerized styrene butadiene rubbers (SBRs) are a common basis for PSA formulation [121]. The tackified SBR PSAs show improved cohesive strength as the Mooney viscosity and percent bound styrene in the rubber increases. The peel performance typically is best with 24—40% bound styrene in the rubber. To increase adhesion to polar surfaces, carboxylated SBRs have been used for PSA formulation. Blends of SBR and natural rubber are commonly used to improve long-term stability of the adhesives. 

Trade Type Grade Oil content Mooney viscosity (T + 8 )... 

Manufacturer Trade Type Grade name elastomer designation Oil content (phr) Mooney viscosity (T + 8 ) at 127 C Ethylene content Diene type Diene content Molecular weight distribution classification... 

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