Rubber bonding

Rubbers differ in their resistance to ozone. All the highly unsaturated rubbers (natural rubber, styrene-butadiene rubber, butyl rubber, nitrile rubber) are readily cracked while the deactivated double carbon-carbon bonds rubber (such as polychloroprene rubber) shows moderate ozone resistance. 

A.N. Gent and P.B. Bindley, Internal rupture of bonded rubber cylinders in tension, Proc. R. Soc. (London), A249, 195-205, 1958. 

I.H. Gregory and A.H. Muhr, Stiffness and fracture analysis of bonded rubber blocks in simple shear, in Finite Element Analysis of Elastomers, ed. by D. Boast and V.A. Coveny, Professional Engineering Publications, Bury St. Edmunds, United Kingdom, 1999, pp. 265-274. 

Cracking of the surface of stretched rubber exposed to ozone. The ozone will only crack unsaturated (i.e., containing double bonds) rubbers when they are subjected to tensile strain, the cracks are at 90° to the direction of the strain. Ozonide... 

Polyurethane adhesives are used for bonding wood, plastics, metals and leather. They can bond rubber to rubber, metal, glass or synthetic fibres. 

Ellul, M.D. and Emerson, R.J. (1988a). A new pull-out test for tire cord adhesion-Part I, Hot bonding. Rubber Chem. Technol. 61, 293-308. 

Protein glues are good for bonding rubber to steel, cork to plywood. Asphalt makes a good adhesive for roofing of homes. 

Bonding agent - An adhesive used to bond rubber to metal or fabric. 

The ability to infiltrate the surface of a host material decreases with molecular size. Molecules ofM > 5 x 103 can hardly diffuse through a porous-free membrane. Self-diffusion is when a molecule moves, say in the melt, during crystallization. Also, when bonding rubber, the so-called tack is explained by the self-diffusion of the molecules. The diffusion coefficient for self-diffusion is of the order of... 

Cox, D. R., Some Aspects of Rubber to Metal Bonding, Rubber Journal, April/May 1969. 

Use Paint and varnish drier, bonding rubber to steel and other metals. 

Use Production of polyurethane foams and elastomers, in phenol-formaldehyde resins to improve water and alkali resistance bonding rubber to rayon or nylon. 

Use Preparation of polyurethane resin and spandex fibers bonding rubber to rayon and nylon. 

OTHER COMMENTS useful in bonding rubber to rayon and nylon used in two-component polyurethane coating systems used for aircraft, tank trucks, and truck trailers also used to produce polyurethane lacquer coatings applied to certain automobile body components other uses are in production of thermoplastic polyurethane resins and spandex fibers. 

The best-known elastomer is natural rubber, poly-isoprene (Scheme 6.10). Isoprene (Scheme 6.10a) is a liquid at room temperature, which polymerises readily to give the elastomer polyisoprene (Scheme 6.10b). The polymerisation produces two main geometrical isomers (see Section S2.1.) Natural rubber is the aU-c form of polyisoprene (Scheme 6.10c), in which the methyl (—CH3) groups and hydrogen (H) atoms are on the same side of the carbon-carbon double bond. Rubber latex, a milky liquid, is a suspension of rubber in water. It is found in many plants (e.g. in dandelions) as well as mbber... 

Efforts to bond rubber to metal without the use of metal plating led to what is believed to be the first research efforts in surface preparation prior to adhesive bonding. Strong and durable bonds of rubber to metal were necessary for rubber shock mounts for automobiles in the late 1920s, but they were limited to proprietary formulations used on specific metals. In 1927 solvent-based thermoplastic rubber cements for metal-to-rubber bonding were prepared from rubber cyclized by treatment with sulfuric or other strong acids. With these rubber cements strong bonds could be made to either vulcanized or unvulcanized rubber. 

During World War II, synthetic rubber and resin-modified phenolics were used to bond aluminum sheets (available only in in. thickness at that time) into billets from which airplane propellers were carved, thus replacing laminated wood, which often shattered on impact with a bullet. Similar adhesives were used to bond rubber to metal in a variety of vibration-damping applications. The most successful widely known product of the new technology was the automotive bonded brake lining first introduced in 1947, and now regarded as a symbol of quality and integrity [12, p. 490]. 

FIGURE 1.19 Sketch of a bonded rubber block under a small compression. The distributions of normal stress a and shear stress t acting at the bonded surfaces are represented by the upper portions of the diagram (from Tobolsky and Mark, 1971). 

Uses Bonding agent for bonding rubber doughs, sol n. coatings, and solv.-based dips to a variety of syn. textiles, rec. for adhesives, esp. those based on polychloroprene and on chlorinated rubbers Properties Dk. bm. low vise, liq. dens. 1070 kg/m (20 C) 54% act. Toxicoiogy Harmful by inh. irritating to skin, eyes, and respiratory tract may cause sensitization by inh. 

Chem. Descrip. Disp. of polymers, org. resins, and fillers in org. soivs. Uses Cover coat and post vulcanization bonding agent adhesive for bonding rubbers to metal and other substrates during vulcanization and post-vulcanization... 

Chem. Desetip. One-component fluoroelastomer based on Viton Uses Sealant/caulk for industrial applies, such as Joint sealant for steel and concrete, door gasket adhesive on industrial ovens, adhesives for flue duct expansion Joints, acid-resist. Joint sealant for industrial flooring, hazardous abatement material, coatings for fuel inj. hoses in automobiles, coatings for equip, subject to corrosive liq., and adhesives for bonding rubber gaskets to metal... 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes Uses Drier for paint, varnish, in food-contact coatings drier migrating from food pkg. adhesion promoter bonding rubber to steel and other metals catalyst accelerator in unsat. polyester resins accelerator in food-contact crosslinked polyesters Regulatory FDA 21CFR 175.300, 177.2420, 181.25... 

Phenol-formaldehyde resin Phenolic resin bonding rubber to rayon/nylon... 

Pofycarbonate is exceptional in this respect. Most pofymers are embrittled by large voids or debonded rubber particles, which act as nuclei for crazes and cracks, whereas the same pofymers are toughened by small well-bonded rubber particles, which generate similar stress concentrations, and are also capable of forming voids, by cavitating under stress. The key hictor appears to be the size of the voids, which determines whether they nucleate crazes and cracks (see Sections 5.3 and 5.4), or promote shear yielding. 

The structural class can be divided into 10 groups, based on particular approach to the problem as, for example, hydrodynamic theories. They belong models of Guth and Gold and Smallwood, but some authors include also the occluded volume theory of Medalia and theories of filler and bonded rubber compact spheres of Brennan and Jermyn and some others. The groups can be described as ... 

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