Natural and Synthetic Rubber. XVII. The Separation of Sol Rubber and Gel Rubber1

AbstractIn general, the main compositions of porcelain and bone china composed of 54-65%wt silica (SiO2), 23-34% wt alumina (Al2O3) and 0.2-0.7%wt calcium oxide (CaO) suitable for preparation high quality ceramic products such as soft-hard porcelain products for teeth and bones, bioceramics, IC substrate and magneto-optoelectroceramics. The quality of ceramic hand mold is depended on raw material and its properties (pH, ionic strength, solid-liquid surface tension, particle size distribution, specific surface area, porosity, density, microstructure, weight ratio between solid and water, drying time, and firing temperatures). The suitable firing conditions for porcelain and bone china hand-mold preparation were firing at 1270°C for 10 h which resulted in superior working molds for making latex films from natural and synthetic rubber. The obtained fired porcelain hand molds at 1270°C for 10 h provided good chemical durability (10%NaOH, 5%HCl and 10%wtNaCl), low thermal expansion coefficient (5.8570 × 10−6 (°C−1)), good compressive (179.40 MPa) and good flexural strength (86 MPa). While thermal expansion coefficient, compressive and flexural strength of obtained fired bone china hand molds are equal to 6.9230 × 10−6 (°C−1), 128.40 and 73.70 MPa, respectively, good acid-base-salt resistance, a smooth mold surface, and easy hand mold fabrication. Both obtained porcelain and bone china hand molds are a low production cost, making them suitable for natural and synthetic rubber latex glove formation.

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Natural and Synthetic Rubber. IV. 4-Methyl-4-Octene by Isoprene Ethylation

Rubber Chemistry and Technology ◽

10.5254/1.3535508 ◽

1930 ◽

Vol 3 (3) ◽

pp. 483-484

Author(s):

Thomas Midgley ◽

Albert L. Henne

Keyword(s):

Double Bond ◽

Synthetic Rubber ◽

Double Bond System ◽

Bond System ◽

Usual Behavior ◽

Natural And Synthetic ◽

Long Chains

Abstract Isoprene has been ethylated; 4-methyl-4-octene was formed exclusively. The structure of this nonene is in agreement with the usual behavior of a conjugated double bond system. This type of addition is further evidence in favor of the hypothesis which regards the polymerization of isoprene to synthetic rubber as the formation of long chains of isoprene units linked together- by ordinary valences in the 1,4-position.

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Molecular weight and chain-length of natural and synthetic rubber

Recueil des Travaux Chimiques des Pays-Bas ◽

10.1002/recl.19330521106 ◽

2010 ◽

Vol 52 (11) ◽

pp. 935-940

Author(s):

A. J. Wildschut

Keyword(s):

Molecular Weight ◽

Chain Length ◽

Synthetic Rubber ◽

Natural And Synthetic

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NATURAL AND SYNTHETIC RUBBER. XI. CONSTITUENTS OF THE MILLED RUBBER HYDROCARBON

Journal of the American Chemical Society ◽

10.1021/ja01347a056 ◽

1932 ◽

Vol 54 (8) ◽

pp. 3381-3383 ◽

Cited By ~ 1

Author(s):

Thomas Midgley ◽

Albert L. Henne ◽

Mary W. Renoll

Keyword(s):

Synthetic Rubber ◽

Natural And Synthetic

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Natural and Synthetic Rubber. XVI. The Structure of Polystyrene

Journal of the American Chemical Society ◽

10.1021/ja01301a038 ◽

1936 ◽

Vol 58 (10) ◽

pp. 1961-1963 ◽

Cited By ~ 8

Author(s):

Thomas Midgley ◽

Albert L. Henne ◽

Henry M. Leicester

Keyword(s):

Synthetic Rubber ◽

Natural And Synthetic

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The Synthesis of Isocyanate-Modified Novolak Resins for Use in Natural and Synthetic Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3535037 ◽

1980 ◽

Vol 53 (2) ◽

pp. 239-244 ◽

Cited By ~ 2

Author(s):

N. D. Ghatge ◽

B. M. Shinde

Keyword(s):

Tensile Strength ◽

Synthetic Rubber ◽

Natural And Synthetic

Abstract Resin-C and Resin-B give higher values for tensile strength, modulus, and hardness than all other resins.

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Effect of Storage and Temperature on Flexibility of Natural and Synthetic Rubbers

Rubber Chemistry and Technology ◽

10.5254/1.3546969 ◽

1948 ◽

Vol 21 (4) ◽

pp. 864-876

Author(s):

John B. Gregory ◽

Irving Pockel ◽

John F. Stiff

Keyword(s):

Low Temperature ◽

Low Temperatures ◽

Strain Curve ◽

Polymer Chains ◽

Stress Strain Curve ◽

Low Temperature Storage ◽

Synthetic Rubber ◽

Loading And Unloading ◽

Temperature Storage ◽

Natural And Synthetic

Abstract A new method for measuring the flexibility of rubber has been described. The method consists essentially in determining the stress-strain curve obtained by loading and unloading a loop formed from a one-inch by six-inch strip cut from a test slab. A coefficient of flexibility independent of the thickness of the sample and, in addition, information on per cent resilience were obtained. By the use of the method described, the behavior of various natural and synthetic rubber gas mask facepiece compounds was studied during one month to three months' exposure at various temperatures down to −20° F. Progressive stiffening probably due to crystallization was found for natural rubber, GR-I, and GR-M compounds at low temperatures. No tendency to crystallize was noted for the GR-S compound. Of the crystallizable polymers GR-I was the most resistant, and GR-M the least resistant to stiffening during low temperature storage. It is of course evident that different polymers have inherently different degrees of resistance to low temperatures. Disregarding these inherent differences the work reported indicates that the resistance of elastomer compounds to stiffening during prolonged low temperature storage is favored by the following: 1. Use of interpolymers made from monomer mixtures having a relatively large proportion of each component, thus obtaining mutual intereference with crystallization. 2. Use of a “tight” cure which probably so impedes the movement of the polymer chains as to make crystallization difficult.

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