Oil extenders

When water is injected into a water-wet reservoir, oil is displaced ahead of the injected fluid. Injection water preferentially invades the small- and medium-sized flow channels or pores. As the water front passes, unrecovered oil is left in the form of spherical, uncoimected droplets in the center of pores or globules of oil extending through intercoimected rock pores. In both cases, the oil is completely surrounded by water and is immobile. There is htde oil production after injection water breakthrough at the production well (5). 

Until the 1960s, reclaimed mbber was an important raw material in molded and extmded mbber products, eg, tires, mbber mats, and hard mbber battery cases. With the advent of vinyl, other plastics, and less expensive oil-extended synthetic polymers, reclaimed mbber sales stabilized and decreased. In 1973, the oil embargo and rising energy costs increased costs of the energy-intensive mbber reclaiming process to the point where they matched virgin polymer costs. Increased radial tire production required crack resistance that could not be provided by reclaimed mbber compounds (46). 

Natural mbber was also used extensively in its oil-extended form in winter tires in the 1970s (57). Use of oil-extended natural mbber treads, found to have excellent traction on ice and snow, superseded studded synthetic mbber treads when studs were banned in certain countries and states owing to the damage they cause to partially cleared roads. This concept has been extended into aH-season tires, which account for over 75% of original equipment and replacement tires in the United States. It has been shown (58) that part replacement of styrene—butadiene mbber (SBR) in the formulation of aH-season tire tread compounds with oil-extended natural mbber increases ice and snow traction, reduces rolling resistance, and has no effect on normal wet grip. Also, there is only a minor trade-off in wear performance, because below a tire surface temperature of approximately 32°C, the wear of natural mbber is superior to SBR, whereas above this temperature the reverse is tme (59). Thus, wear of an aH-season tire ultimately depends on the surface temperature of the tread over its annual cycle of temperatures. 

Black masterbatch can be made with or without oil-extended SBR. Commercially there are available, worldwide, 11 numbered ESBR cold black masterbatches and 15 ESBR cold oil-black masterbatches (27). These types range in black type and content as well as oil type and amount. Of course, not every listed product is available from every supplier. 

The initial production of GR-S mbber required a learning period in processing before mbber workers were comfortable with the new synthetic mbber. Although softer and more plastic initially, the GR-S did not break down as much as natural mbber. Once familiar with the differences, processing GR-S was handled quite comfortably. The same was tme when the cold GR-S was introduced, followed by the oil-extended version, and SSBR. 

Catalyst residues, particularly vanadium and aluminum, have to be removed as soluble salts in a water-washing and decanting operation. Vanadium residues in the finished product are kept to a few ppm. If oil-extended EPDM is the product, a metered flow of oil is added at this point. In addition, antioxidant, typically of the hindered phenol type, is added at this point. 

Evaluation procedures, ISO 4097 Jihher, ethylene—propylene—diene (EPDM), Non-oil extended raw general-purpose types, 1992. 

The development of oil-extended SBR in which a rubbery polymer of very high molecular weight is blended with substantial amounts of hydrocarbon oil. This provides a lower cost alternative to a polymer of more conventional average molecular weight. 

Chemistry of SBR. There are three steps in the manufacturing of SBR polymerization, monomer recovery and finishing. The polymerization step determines the basic characteristics of SBR, whereas the product form (latex or dry rubber, oil extended or not) depends on the finishing step. 

These data for typical properties of EP polymers are either as measured or as advertised by respective manufacturers. This table is not intended to be definitive either in terms of the total grade slate or the specific data reported for each producer. Note that the molecular weight distribution data are based on a qualitative comparison of GPC curves. Mooney viscosities are repotted for final product form (i.e.. in the case of oil-extended rubbers, the viscosity is that of the EP plus oil. 

It is thus apparent that at the commencement of vegetation of the peppermint the oil is rich in menthol, hut only a small amount is present in the esterified condition. Menthone only exists in small quantity. As the green parts of the plant develope, the proportion of esterified menthol increases, as has heen found to be the case with other alcohols. This esterification, however, only takes place in the leaves, and when the essential oil extends towards the flowering tops, it becomes poorer in esters. 

Some 70-85 per cent of failures and wear problems in lubricated machines are caused by oil contamination. Clean oil extends machine and oil life and gives greater reliability, higher productivity and lower maintenance cost. Hence, some type of filter is an essential part of virtually all lubrication systems. 

FIGURE 33.8 Strain dependence of G for oil extended solution SBR (OESSBR)/BR and natural rubber (NR) filled with a variety of fillers. 

Standardisation of EPDM characterisation tests (molecular composition, stabiliser and oil content) for QC and specification purposes was reported [64,65]. Infrared spectroscopy (rather than HPLC or photometry) is recommended for the determination of the stabiliser content (hindered phenol type) of EP(D)M [65]. Determination of the oil content of oil-extended EPDM is best carried out by Soxhlet extraction using MEK as a solvent [66], A round robin test was reported that evaluated the various techniques currently used in the investigation of unknown rubber compounds (passenger tyre tread stock formulations) [67]. 

SBR, 23.5% styrene oil-extended 27% oil. c Parts by weight per hundred parts resin. 

Process oils - Extender oils - Mineral oils Reclaiming agents Reducing agents Reinforcements... 

Petroleum and other hydrocarbons oils obtained from mineral sources. In rubber compounds they act as softeners and extenders. See Oil Extended Polymer. 

An oil extended polymer to which has been added at the latex stage a quantity of a reinforcing carbon black. 

A type of SBR with which has been mixed in the latex stage a quantity (usually 37.5 or 50 phr) of an emulsion of a mineral oil and the mixture coagulated and processed in the normal manner. Although other synthetic rubbers may be oil extended in this way, the abbreviation OEP usually refers only to SBR. See Oil Extension. 

The addition of a high proportion (40-50 phr) of a rubber processing oil to an elastomer with the object of improving the processibility of a tough polymer and/or cheapening the compound. See Oil Extended Polymer. 

NR is available in a granular form (powdered rubber), and in oil extended grades. 

NR requires a certain degree of mastication (reduction in molecular weight) to facilitate processing, although the advent of constant viscosity grades, and oil extended grades has substantially reduced the need for mastication. 

Oil extended SBR, and SBR carbon black masterbatches are supplied by the polymer producers and such grades give the advantage of reducing the necessity of further additions of filler and oil at the mixing stage. 

UV and/or heat stabilized, oil extended, low temperature, soft touch, transparent, ster-ilizable, food contact, for heavy soundproofing parts, high purity for medical or pharmaceutical applications, very low hardness, conductive, additives for modification of other polymers. .. 

Uses Solvent for nitrocellulose, ethyl cellulose, polyvinyl butyral, rosin, shellac, manila resin, dyes fuel for utility plants home heating oil extender preparation of methyl esters, formaldehyde, methacrylates, methylamines, dimethyl terephthalate, polyformaldehydes methyl halides, ethylene glycol in gasoline and diesel oil antifreezes octane booster in gasoline source of hydrocarbon for fuel cells extractant for animal and vegetable oils denaturant for ethanol in formaldehyde solutions to inhibit polymerization softening agent for certain plastics dehydrator for natural gas intermediate in production of methyl terLbutyl ether. 

Uses Oil extender solvent gasoline component organic synthesis. 

Most polystyrene products are not homopolystyrene since the latter is relatively brittle with low impact and solvent resistance (Secs. 3-14b, 6-la). Various combinations of copolymerization and blending are used to improve the properties of polystyrene [Moore, 1989]. Copolymerization of styrene with 1,3-butadiene imparts sufficient flexibility to yield elastomeric products [styrene-1,3-butadiene rubbers (SBR)]. Most SBR rubbers (trade names Buna, GR-S, Philprene) are about 25% styrene-75% 1,3-butadiene copolymer produced by emulsion polymerization some are produced by anionic polymerization. About 2 billion pounds per year are produced in the United States. SBR is similar to natural rubber in tensile strength, has somewhat better ozone resistance and weatherability but has poorer resilience and greater heat buildup. SBR can be blended with oil (referred to as oil-extended SBR) to lower raw material costs without excessive loss of physical properties. SBR is also blended with other polymers to combine properties. The major use for SBR is in tires. Other uses include belting, hose, molded and extruded goods, flooring, shoe soles, coated fabrics, and electrical insulation. 

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