Tire materials rubber compounding

S. Bandyopadhyay, S. Dasgupta, S.L. Agrawal, S.K. Mandot, N. Mandal, R. Mukhopadhyay, A.S. Deuri, and S.C. Ameta, Use of recycled tire material in NR/BR blend based tire tread compound Part II (with ground cmmh mhher). Progress in Rubber, Plastics and Recycling Technology, 22(4), 269, 2006. 

In summary, materials scientists must consider the implications of their materials choices, from the quantity of energy to manufacture the product, to the performance during its useful life cycle, and Anally to disposal methods. US Environmental Protection Agency (EPA) also provides constraints that the materials scientists must consider in the design of compounds. As most rubber compounds contain approximately 6-20 different materials, not only the materials themselves must be clean and harmless, but any by-products that form during product tire manufacturing must also be harmless to humans and the environment. 

A final word in this short summary of impact modification concerns the amount of imagination compounders and polymer scientists continue to invest in the development of rubber-modified compoimds. Efforts are being made to decrease their compounding costs, to enhance their paintability, and to formulate them to replace more competing materials such as ABS, thermoset rubber, and PVC—thereby allowing more recyclable "aU-olefin" automotive interiors, for example. Recent efforts have even been made to incorporate ground vehicle tire rubber or other "ultrafine rubber particles into PP to create vulcanized elastomeric thermoplastics that cost less than half as much as standard TPVs. Similar concepts will continue to push impact-modified POs into new applications [7-26, 7-27, 7-28]. 

Py-GC/MS of samples (prepared as were the ICM samples) of the four materials thought to be the major sources of the tunnel air particulates — tire rubber, road salt, diesel exhaust, and gasoline exhaust — showed that road salt gave no pyrolysis products and the other three materials gave pyrograms of complexity similar to those of the ICM samples. The overlap of compound types and the absence of unique marker compounds made an assessment of the relative contribution of each of the three sources to the total impractical using the Py-GC/MS profiles. 

Dip [ME dippen, fr. OE dypparr, akin to OHGr tupfen to ash, Lithuanian dubus deep] (before 12c) v. (1) Immersion of a textile material in some processing liquid. The term is usually used in connection with padding or slashing process. (2) The rubber compound with which tire cords and other in-rubber textiles are treated to give improved adhesion to rubber. 

Materials. Tire compounds contain the following generalized ingredients in the approximate proportions noted. Industry practice is to formulate starting with 100 parts per hundred weight of the rubber (phr). Table 22 offers examples for various treads. 

Zinc oxide is essential in rubber technology because it is the most commonly used activator for sulfur cure systems. Just about every rubber compound that uses sulfur as the vulcanizing agent will most likely contain a small amount of zinc oxide to activate the cure. Also zinc is alloyed with copper to form brass. Special brass-plated steel tire cord is a primary reinforcing material for producing steel-belted radial tires. The brass coating of the steel tire cord enables very good rubber-to-metal adhesion. Therefore, zinc metal and zinc oxide are very important to the rubber industry. 

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