Elastomer to metal

J. F. E. Ruffel Durham Raw Materials Ltd Paper "Elastomer to Metal Bonding" read at West England section Conference at Trowbridge 5th march 1968. Journal of the IRI, August 1969, Vol. 3, Number 4. 

R.Y. Ting, "Elastomer-to-Metal Adhesion in Sonar Transducer," to be published in Polymer News, 1984. 

This paper will review briefly a number of adhesion mechanisms that have been put forth to describe the joining of vulcanizing elastomers to metals. It will then be argued that some of these same mechanisms are equally useful to explain the adherence of vulcanizing elastomers to textiles. Considerable emphasis will... 

There are other examples of material approaches that have contributed to our interpretation of elastomer-to-metal bonding mechanisms, but all can be rationalized under one or more of the processes in the following schematic (Figure 6). Here, we have tried... 

It seems appropriate to close this discussion of textile-to-elastomer vulcanization bonding with the same type of schematic portrayal as was shown earlier for elastomer-to-metal adhesion (Figure 23). Not all of these phenomena or processes can be operative for any single bonding system, but each would appear to be a possibility in one or more of the material approaches that have been cited. 

However, recently developed adhesive primers improve the bond of these elastomers to metal. Surface treatment of the adherend before priming should be according to good standards. 

Cambridge, UK, 15th-17th Sept. 1999, p.55-60 TIME DEPENDENT MECHANICAL FAILURE OF STRONG ELASTOMER-TO-METAL BONDS CHEMICAL OR PHYSICAL MECHANISM Albihn P Chapman A V Lake G J Lawrence C C Swedish Institute for Fibre Polymer Research Malaysian Rubber Producers Research Assn. East London, University (lOM Communications Ltd.)... 

G.K. Cowell and D.J. Cherry, Metal deactivators as adhesion promo-tors for vulcanizable elastomers to metals, US Patent 3994987, assigned to Ciba-Geigy Corporation (Ardsley, NY), November 30,1976. 

Bonding Elastomers to Metals with MDI-50, Elastomers Division Bulletin, BL-241 (Apr. 30, 1951), E. I. du Pont de Nemours Co., Wilmington, Del. 

Polyurethane Polyurethane adhesives are created from isocyanates. Often used for bonding polymers (especially elastomers) to metal. A specific example is the bonding of SMC that is used in automotive body panels to steel. 

Adhesion. Commercially available 1- or 2-coat adhesive systems produce mbber failure in bonds between ethylene—acryflc elastomer and metal (14). Adhesion to nylon, polyester, or aramid fiber cord or fabric is greatest when the cord or fabric have been treated with carboxylated nitrile mbber latex. 

There have been other approaches to obtaining rubber/metal adhesion besides primers or additives consisting of phenolics or epoxies plus halogenated elastomers. For example, carboxylated polymers (olefins and diolefins copolymerized with acrylic acid monomers) have shown excellent adhesion to metals. Very little carboxyl is necessary, and polymers with carboxyl contents as low as 0.1% show good adhesion when laminated to bare steel. When these materials possess... 

Formulation of a solvent-borne CR. A typical formulation of a solvent-borne CR adhesive may include the following components (fillers are not commonly added and curing agents are added to improve heat resistance) (1) polychloroprene elastomer (2) metal oxides (3) resins (4) antioxidants (5) solvents (6) fillers (7) curing agents (8) other modifiers. 

Ball valves are limited in temperature by the elastomer material used in their seats. Many designs have a secondary metal-to-metal seat to provide a seal in case of fire. Ball valves are not suitable as a throttling valve, but can be used on start-up and shut-down in the partially open position to bleed pressure into or out of a system. 

When metal inserts require hermetic sealing, consider coating them with a flexible elastomer such as an RTV rubber, polyurethane, or epoxy system. A second method is to design an annular space or reservoir at one end of the insert from which to dispense the flexible elastomers to effectively create a hermetic seal. Flexible sealants are also used to compensate for differences in the thermal coefficient of expansion between metal and plastic. 

Radiation In general, plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. The materials that will respond satisfactorily in the range of I010 and 10n erg per gram include... 

However, not all properties are improved by filler. One notable feature of the mechanical behaviour of filled elastomers is the phenomenon of stresssoftening. This manifests itself as a loss of stiffness when the composite material is stretched and then unloaded. In a regime of repeated loading and unloading, it is found that part of the second stress-strain curve falls below the original curve (see Figure 7.13). This is the direct opposite of what happens to metals, and the underlying reasons for it are not yet fully understood. 

Most mechanical and civil engineering applications involving elastomers use the elastomer in compression and/or shear. In compression, a parameter known as shape factor (S—the ratio of one loaded area to the total force-free area) is required as well as the material modulus to predict the stress versus strain properties. In most cases, elastomer components are bonded to metal-constraining plates, so that the shape factor S remains essentially constant during and after compression. For example, the compression modulus E. for a squat block will be... 

The commercial products contain one chlorine atom per 2-3 repeat units and about one chlorosulfonyl group per 70 repeat units. The chlorosulfonyl groups allow the elastomer to be vulcanized with metal oxides such as lead or magnesium oxide by the formation of metal sulfonate linkages ... 

When aggressive gases or vapors have to be pumped, valves made of stainless steel and sealed with VITILAN sealant are usually used. For nuclear technology, valves have been developed that are sealed with special elastomer or metal gaskets. We will be pleased to provide further design information for your area of application upon request. 

Similarly, the coammonolysis of a mixture of dimethyldichlorosilane and vinyltrichlorosilane can yield polyvinylmethyldimethylsiloxane varnish, which has a relatively high adhesion to metals, glass and rubber based on silicone elastomers this varnish is also used in glue compositions. The coammonolysis of a mixture of dimethyldichlorosilane and phenyltrichlorosilane produces polydimethylphenylsilazane varnish. 

Borosilicate glass is a range of glasses based on boric oxide, silica, and a metal oxide. It has excellent thermal shock resistance and chemical resistance. A recent patent claimed the use of borosilicate glass powder (50-100 phr) in conjunction with expandable graphite (100 phr) or vermiculite in polyolefin, epoxy, or elastomers to achieve good fire retardancy (as evidenced by the Cone Calorimeter test at 35 kW/m2).99... 

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