Chemigum SL—An Elastomeric Polyester-Urethane

1954 ◽  
Vol 27 (2) ◽  
pp. 430-438 ◽  
Author(s):  
N. V. Seeger ◽  
T. G. Mastin ◽  
E. E. Fauser ◽  
F. S. Farson ◽  
A. F. Finelli ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Polyester Urethane ◽  
Patent Literature ◽  
Work Done ◽  
Very High ◽  
Made In

Abstract A great deal of interest has been aroused in recent years in isocyanate chemistry by the announcement of new elastomers based on diisocyanate modification of polyesters. Early du Pont patent literature described diisocyanate modified alkyds, and Vulcaprene A, an elastomeric diisocyanate modified polyesteramide, has been offered to the rubber trade by Imperial Chemical Industries, Ltd., England. Several articles also have been published on Vulcollan by Bayer and associates on work done in the laboratories of Fabenfabriken Bayer Co., Leverkusen, Germany. More recently a new elastomeric polyester-urethane, Chemigum SL, was described by the Goodyear Tire and Rubber Co. These rubbers are first made in the form of processible and storable raw gums, having many of the characteristics of pale crepe natural rubber. They can then be mixed on the mill or in the Banbury with additional curatives, such as diisocyanates and other compounding agents, and cured in standard rubber molds. The cured physical properties of Chemigum SL are very similar to Vulcollan; both exhibit unusual toughness. Tensile strength is very high, as is resistance to cutting and chipping. Since the polyester-urethanes are saturated, cut-growth resistance is excellent. Even when cuts are initiated by sharp objects, there is no tendency to grow, even under stress. In this respect a vast superiority is shown over natural rubber or GR-S.

Pigment Incorporation in GR-S through Latex

1945 ◽  
Vol 18 (1) ◽  
pp. 122-129
Author(s):  
W. McMahon ◽  
A. R. Kemp
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Magnesium Oxide ◽  
Natural Rubber Latex ◽  
Calcium Carbonates ◽  
Carbon Blacks ◽  
Zinc Oxides ◽  
Made In

Abstract The physical properties of GR-S gum stock are decidedly inferior to those of natural-rubber gum stock, and they have to be greatly enhanced for practical use of the elastomer. At present these physical properties are augmented to the greatest degree by compounding with reinforcing pigments, especially carbon blacks. Furthermore, experience has shown that, for a given pigment, the reinforcement it affords is proportional to the degree to which it is dispersed in the elastomer. A thorough dispersion of pigment on the mill or in the Banbury mixer is not feasible with schedules which can be applied in the factory, particularly with those pigments which are more difficult to disperse. A study of the relation between the characteristics of pigments used as fillers in GR-S and their reinforcing properties indicated that the particle size of the pigment was the predominant characteristic associated with reinforcing ability. The finer carbon blacks yielded the greatest reinforcement, measured by ultimate tensile strength; also, a fine grade of magnesium oxide yielded compounds with tensile strengths approximately equal to stocks made with blacks of the same particle size. Stocks made from a coarser magnesium oxide were considerably lower in tensile strength, and zinc oxides and calcium carbonates fell roughly in the order of their particle sizes. The calcium carbonates, zinc oxides, and magnesium oxides had to be worked on the mill much more than the carbon blacks to develop maximum reinforcement; and, even though well worked, the finest zinc oxide and calcium carbonate did not yield compounds with properties which their particle size indicated they should have. It was felt that this was due to inability to disperse these materials properly on the mill; thus their effective particle size in the compound was much greater than their ultimate size. Accordingly, a better means was sought to disperse fillers in GR-S than that afforded by milling. It was known that excellent dispersions of pigments could be made in water with the aid of dispersing agents. It was also reported that the polymer particles in GR-S latex were very finely divided, less than one-tenth the diameter of particles in natural rubber latex. If, then, a water suspension of well dispersed pigment was mixed with latex, and the filler and polymer were precipitated or coagulated simultaneously, it was thought that the pigment might be more thoroughly dispersed in polymer than it would be through dry milling; the physical properties of compounds made in this manner should then show improvement over those made on the mill.

DURIMPHY

Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Yield Strength ◽  
Physical Properties ◽  
Precipitation Hardening ◽  
Heat Treating ◽  
High Yield ◽  
High Yield Strength ◽  
Precision Alloys ◽  
Very High

Abstract Durimphy is a maraging steel with 1724 MPa (250 ksi) tensile strength and a very high yield strength due to precipitation hardening. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: FE-140. Producer or source: Metalimphy Precision Alloys.

ATI 35N

Alloy Digest ◽  
2021 ◽  
Vol 70 (2) ◽  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Heat Treated ◽  
Cold Worked ◽  
Multi Phase ◽  
Very High

Abstract ATI 35N is a wrought, multi-phase Co-Ni-Cr-Mo alloy that can be heat treated to achieve very high strength, while maintaining excellent toughness, ductility, and corrosion resistance. To achieve tensile strength levels of 1795 to 2070 MPa (260 to 300 ksi), the alloy is cold worked and then precipitation hardened. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Co-133. Producer or source: ATI.

Vulcanization Characteristics of Mercaptobenzothiazole Derivatives

1937 ◽  
Vol 10 (2) ◽  
pp. 329-335 ◽  
Author(s):  
M. W. Harman
Keyword(s):  
Hydrogen Atom ◽  
Physical Properties ◽  
Mercapto Group ◽  
Preliminary Processing ◽  
The Past ◽  
Curing Characteristics ◽  
Patent Literature ◽  
Commercially Important ◽  
Derivatives Of ◽  
Made In

Abstract WITHIN the past few years much progress has been made in the development of rubber vulcanization accelerators of the semi-ultra type which exhibit no prevulcanization or scorch during the preliminary processing. Most of the commercially important members of this class are derivatives of mercaptobenzothiazole in which the hydrogen atom of the mercapto group is replaced by an organic substituent. The increasing use of these products can be attributed to their favorable curing characteristics and to the valuable physical properties which they impart to the cured stock. Naunton and his co-workers (4), Twiss and Jones (8), and Shepard (6) discussed a number of these compounds in recent papers. Numerous references to their preparation and use also appear in the patent literature (1,2,3,5,7,10).

Measurement of the Absorption of Oxygen by Vulcanized Rubber in Air

1939 ◽  
Vol 12 (2) ◽  
pp. 261-268
Author(s):  
A. G. Milligan ◽  
J. E. Shaw
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Tensile Tests ◽  
Direct Measure ◽  
Mean Values ◽  
Reasonable Time ◽  
Aging Period ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Made In

Abstract It is generally agreed that oxidation is the controlling factor in the decay of rubber compounds. Measurements of the decay of any physical properties—commonly tensile strength—can be made in a convenient time only if the decay is greatly accelerated, and there is always a grave doubt about the equality of the acceleration for different materials. There is also a difficulty in selecting a universally suitable aging period, since the decay of the physical properties is not linear. A direct measure of the rate of oxidation is, in our view, more fundamental and less equivocal. It can, moreover, be made in a reasonable time at a temperature not far removed from service temperatures. Again, whereas tensile tests require several samples of each point in the timecurve to give acceptable mean values, here a single sample suffices for the whole test, and this sample can be simply prepared from a specimen of any form by rasping. The merits and simplicity of the method should commend it to rubber technologists.

Polybutadienes of Controlled Cis, Trans and Vinyl Structures

1959 ◽  
Vol 32 (2) ◽  
pp. 614-627 ◽  
Author(s):  
J. N. Short ◽  
G. Kraus ◽  
R. P. Zelinski ◽  
F. E. Naylor
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Natural Rubber ◽  
Physical Properties ◽  
Abrasion Resistance ◽  
High Hardness ◽  
High Modulus ◽  
High Tensile Strength ◽  
Truck Tires ◽  
Wide Range

Abstract The physical properties of polybutadiene vulcanizates have been measured as a function of polymer microstructure. Although the over-all properties of any one polybutadiene are determined by the relative ratio of cis, trans and vinyl units in the polymer chain, marked changes in physical properties do not occur until a relatively pure configuration is approached or unless the raw polymer displays crystallinity. Thus, polybutadienes containing more than 85 per cent cis, trans or vinyl units are characteristically different from each other and the differences are accentuated as the isomeric forms approach 100 per cent of a given configuration. Polybutadiene of 95 per cent cis configuration displays very low heat generation and high resilience (equaling natural rubber in these properties) and excellent abrasion resistance. trans-Polybutadiene (90 per cent), a crystalline plastic in the raw state, becomes rubbery after vulcanization. Gum vulcanizates possess high tensile strength, and tread stocks display high modulus and tensile strength, high hardness and fair hysteresis properties. Vulcanizates of amorphous 94 per cent vinyl polybutadiene are characterized by fair tensile properties, low hysteresis, and poor low temperature properties. Crystalline syndiotactic polybutadiene, 70 per cent vinly, displays much higher gum and tread tensile strengths than its amorphous counterpart. Amorphous polybutadienes containing less than 70–80 per cent of any one configuration are generally similar in most properties, and resemble emulsion polybutadiene in many respects. The wide range of properties of the various polybutadienes makes them suitable for many applications. cis-Polybutadiene is an excellent tire rubber, which has given as much as 40 per cent greater abrasion resistance than natural rubber in passenger tire tests. Heavy duty 10:00 × 20 truck tires fabricated with a 1:1 blend of cis-polybutadiene and natural rubber in the treads have given slightly better abrasion ratings and lower running temperatures than control tires fabricated entirely from natural rubber. Amorphous 80 per cent cis-polybutadiene has been found to possess exceptionally good low temperature properties, far superior to present arctic-type unsaturated elastomers, trans-Polybutadienes by virtue of their high modulus, high tensile strength, and high hardness could be utilized in the preparation of hard rubber goods, floor tiles, and shoe soles. While none of these polybutadienes is yet available commercially, their unusual properties and potential applicability in many areas should lead to their manufacture in the future.

Effect of Carbon Black on Curing Behavior, Mechanical Properties and Viscoelastic Behavior of Natural Sponge Rubber-Based Nano-Composites

2012 ◽  
Vol 510-511 ◽  
pp. 532-539 ◽  
Author(s):  
M.A. Bashir ◽  
M. Shahid ◽  
R.A. Alvi ◽  
A.G. Yahya
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Physical Properties ◽  
Viscoelastic Behavior ◽  
Nano Composites ◽  
Curing Behavior ◽  
Auxetic Materials ◽  
Viscosity Variation

Natural rubber (polymer designation cis-1-4 polyisoprene, is obtained from the sap ("latex") of several rubber-yielding plants (e.g.,HeveaBrasiliensisandPartheniaargentatum) by coagulation with chemicals, drying, electrical coagulation, and other processes. Foamy or sponge structure of natural rubber (NR) is very useful in aerospace and as auxetic materials (exhibiting negative poisons ratio) for use in application of homeland security.The main aim of this research to estimate the influence of carbon black on mechanical properties, curing and viscosity variation behaviors of the natural rubber based composites. Different amounts of carbon black were used along with other fillers. The influence of carbon black on curing behavior and mechanicalproperties of natural rubber foams was investigated at different feedingratios of the carbon black. The physical properties of the foamed NRs were then measured as a function of carbon blacks content. The mechanical properties of the foamed NRs such as tensile strength,strength at break and modulus,were gradually increased with increasingcarbon black content whereas elongation decreasedat break.

Study of Cure Synergism of the Thiocarbamylsulfenamide-Dibenzothiazyl Disulfide Accelerator System in the Vulcanization of Natural Rubber

1983 ◽  
Vol 56 (4) ◽  
pp. 827-837 ◽  
Author(s):  
D. Pal ◽  
B. Adhikari ◽  
D. K. Basu ◽  
A. K. Chaudhuri
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Structural Characterization ◽  
Crosslink Density ◽  
Synergistic Activity ◽  
Elongation At Break ◽  
Equimolar Concentration ◽  
Accelerator System

Abstract N-cyclopentamethylenethiocarbamyl-N′-cyclopentamethylenesulfenamide (CPTCS) and dibenzothiazyldisulfide (MBTS), as binary accelerators in a mixture have been found to provide significant mutual enhanced activity with regard to modulus, tensile strength, hardness, and elongation at break in the vulcanization of NR gum stocks. The synergistic activity of the CPTCS-MBTS system is very much dependent upon the accelerator ratios, concentration of sulfur and accelerator, as well as the temperature of vulcanization. Investigations carried out with the Monsanto rheometer also corroborate the above results. It is suggested that the synergism arises out of the interaction between CPTCS and MBTS which produces intermediate accelerators. N,N-Diethylthiocarbamyl-N′-cyclohexylsulfenamide (DETCS) in conjunction with MBTS, produces similar results in the vulcanization of NR. Structural characterization of the vulcanizates obtained at 140 and 160°C reveals that predominantly monosulfidic linkages are obtained with CPTCS or DETCS and MBTS combinations. The intermediate combinations, at near equimolar concentration of the two accelerators, exhibit maximum crosslink density. An attempt has been made to correlate physical properties with crosslink density as well as various types of crosslinks.

Rupture of Rubber. IV. Tear Properties of Vulcanizates Containing Carbon Black

1957 ◽  
Vol 30 (2) ◽  
pp. 584-595
Author(s):  
H. W. Greensmith
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Physical Properties ◽  
Different Types ◽  
Tear Properties

Abstract A method of studying tear behavior has been described in a previous paper (Part III, subsequently referred to as III), and was illustrated by results obtained with natural rubber and GR-S gum vulcanizates, i.e., vulcanizates containing no added ingredients apart from those necessary for vulcanization. In the present paper the method is applied to vulcanizates containing different types of carbon black. Vulcanizates of this type are of considerable interest, since the carbon black can appreciably modify physical properties such as stiffness and tensile strength and can induce pronounced anisotropy in tearing, referred to by Buist as knotty tearing.

Physical Properties of Diene Polymers. Effects of Side Vinyl Groups and Other Structural Features

1948 ◽  
Vol 21 (3) ◽  
pp. 596-604
Author(s):  
James D. D'Ianni
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Molecular Structures ◽  
Acid Oxidation ◽  
Similar Data ◽  
Molecular Weight Range ◽  
Brittle Point ◽  
Organometallic Catalyst ◽  
Butadiene Styrene

Abstract The detailed molecular structures of natural rubber, emulsion polyisoprene, polyisoprene prepared with an organometallic catalyst, and sodium polyisoprene were studied by comparison of data available from infrared absorption spectra, perbenzoic acid titration, refractive index, density, iodine number, chromic acid oxidation, and hydrochlorination. These polymers showed decreasing amounts of 1,4-addition content in the order listed. Similar data were collected where possible for emulsion polybutadiene, polybutadiene prepared with an organometallic catalyst, and potassium polybutadiene (Buna-85), as well as for GR-S and corresponding butadiene-styrene copolymers prepared with an organometallic catalyst and with sodium. These two groups also showed decreasing 1,4-addition content in the order listed. Correlation of structure inferred from the above data with physical properties of corresponding tread stock vulcanizates indicated that for diene polymers with decreasing amount of 1,4-addition content the brittle point rose, the rebound value decreased, and the tensile strength increased, provided comparison was restricted to polymers of approximately the same molecular weight range made with the same monomer. Natural rubber occupied a unique position because it was substantially a linear high polymer with the cis-configuration around all the double bonds. For the butadiene-styrene 75/25 copolymers the brittle point rose with decreasing amount of 1,4-addition content, but no satisfactory correlation could be obtained for the tensile strength and the rebound value, probably because of the predominant effect of the phenyl side groups.

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