Powdered rubbers

Several authors have discussed the ion exchange potentials and membrane properties of grafted cellulose [135,136]. Radiation grafting of anionic and cationic monomers to impart ion exchange properties to polymer films and other structures is rather promising. Thus, grafting of acrylamide and acrylic acid onto polyethylene, polyethylene/ethylene vinyl acetate copolymer as a blend [98], and waste rubber powder [137,138], allows... 

Handbook of elastomers , A.K. Bhowmick and H.L. Stephens Marcel Dekker (1988) Series Plastics Engineering, Volume 19 ISBN 0824778006. This handbook systematically addresses the manufacturing techniques, properties, processing, and applications of rubbers and rubber-like materials. The Handbook of Elastomers provides authoritative information on natural rubbers, synthetic rubbers, liquid rubbers, powdered rubbers, rubber blends, thermoplastic elastomers, and rubber-based composites— offering solutions to many practical problems encountered with rubber materials. 

Rubber powder from scrap tires readily absorbs oil floating on water and forms a cohesive mass, which can be easily removed. The amount of oil take up and weight of oil absorbed depends on the particle size of waste tire powder, temperature, and type of oil the weight of oil absorbed is directly proportional to the amount of rubber powder [65]. The oil uptake time decreases as the particle size decreases. 

The ductility of GRT-polyethylene blends drastically decreases at ground rubber concentration in excess of 5%. The inclusion of hnely ground nitrile rubber from waste printing rollers into polyvinyl chloride (PVC) caused an increase in the impact properties of the thermoplastic matrix [76]. Addition of rubber powder that is physically modihed by ultrasonic treatment leads to PP-waste ethylene-propylene-diene monomer (EPDM) powder blends with improved morphology and mechanical properties [77]. 

FIGURE 38.5 Elongation at break of polypropylene-maleic anhydride grafted polypropylene (PP-MA-g-PP)-rubber powder composites as a function of rubber powder content. (Reprinted from Shanmugharaj, A.M., Kim, J.K., and Ryu, S.H., Polymer Test., 24, 739, 2005. Courtesy of Elsevier, U.K.)... 

Wagenknecht, U., Steglich, S., Wiessner, S., and Michael, H., Rubber Powder—A perspective fiber of thermoplastics, Macromol. Symp., 221, 237, 2005. 

The first step — hydrogenation of coal — was the same for fuels and rubber. Powdered coal suspended in oil was pumped under great pressure with hydrogen over a catalyst and was converted into a synthetic crude oil. From this crude oil came Leuna gasoline, diesel fuel, iso-octane for aviation gasoline, ethylene oxide, and many other synthetic products. Coal, treated with scalding steam, was also processed into methanol. 

GLOVES SURGEONS RUBBER POWDER-FREE SZ 7.5 STERILE DISPOSABLE 50S 6515012534260 PG 65 88 ... 

Shellac, boiled linseed oil, resins, paraffin wax, beeswax, litbographic varnish and acaroid resin are used in various pyrotechnic formulations. Similarly chlorinated rubber powder has also been used successfully as a binder. Some of tbe waxes and resins which are of natural origin are still popular and are in use. In order to improve quahty and avoid batch-to-batch variation, manufacturers of pyrotechnics are moving from natural binders to man-made binders. 

Romenesko DJ, Mullan SP (1993) Poly(phenylene ether) resin modified with silicone rubber powder. EP Patent 543 597... 

Chung JYJ, Mason JP (1996) Toughened aromatic polycarbonate containing silicone rubber powder as molding composition. US Patent 5556908... 

D. Boukadir et al.. Preparation of a convenient filler for thermoplastics by pyrolysis of rubber powder recovered from tyres. Journal of Analytical and Applied Pyrolysis, 3, 83-89 (1981). 

Vulcanizate Components. A rubber powder (50-100 micron grain size) recovered from old tires was used. The composition of this material was 55 percent rubber hydrocarbon, 14 percent acetone extractables... 

In a typical process rubber powder, mainly SBR of old tires with 1.6% sulfur, was treated with different species of Thiobacillus, i.e., Thiobacillus ferrooxidans, Thiobacillus thiooxidans, and Thiobacillus thioparus in shake flasks and in a laboratory reactor. The sulfur oxidation depends to a large extent on the particle size. The best results were obtained with T. thioparus with a particle size of 100-200 pm. Of the total sulfur of the rubber powder, 4.7 /o was oxidized to sulfate within 40 days.f ... 

Fillers, such as graphite and rubber powder, also increased the sould absorption while affecting only Insignificantly the rebound and hysteresis. 

As rubber has a much better coefficient of friction compared with polyoleflns, it might be helpful to add rubber powder or small particles into, say, HDPE-based composite matrix. Coarse grades of calcium carbonate could serve the same purpose (this would be again a certain trade-off in properties of the flnal composite material). Additional benefits can be obtained if the same additive/ filler enhances both friction and impact resistance (a rubber might be a good candidate in this case). 

PE/hydrolyzed collagen (98) PE/hydrolyzed collagen (98) PE/acrylonitrile-co-butadiene (100) PE/scrap rubber powder (165)... 

Accetta A. and J.M. Vergnaud. 1982. Rubber recycling. Upgrading of scrap rubber powder by vulcanization, n. Rubber Chem. Technol. 55 961-66. 

The rubber material is obtained by curing a scrap rubber powder at various times and temperatures, and the various values of the state of cure are calculated from the partial heat evolved from the cure reaction measured by calorimetry, as already shown in Chapter 4. The dynamic properties in compression are determined at room temperature by using several samples for which the state of cure is ranging from 36 to 90%. The apparatus used enables the measurement of the visco-elasticity of the rubber sample under various conditions such as compression, traction, shear (vis-coelasticimeter from Metravib, France). 

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