Oil - resistant rubber with the system
First, oil-resistant rubber
Oil resistance usually refers to non-polar oils: fuel, mineral oil and synthetic lubricants.
Rubber according to oil resistance classification (polar rubber): CR, NBR, HNBR, ACM, AEM, CSM, FKM, FMVQ, CO, PUR.
Non-oil resistant rubber classification (non-polar rubber): NR, IR, BR, SBR, IIR, EPR, EPDM.
1 Fuel resistance:
Fluorocarbon FKM and Fluorosilicone Rubber FMVQ have the best resistance to fuel oil. The chloroprene rubber and chlorinated polyethylene rubber CPE fuel resistance of the worst. The flammability of the rubber was improved with the increase of the acrylonitrile content. Chlorohydrin rubber is better resistant to oil than nitrile rubber.
2 resistant to mixed fuel:
Fluorosilicone rubber FMVQ and Fluoroelastomer FKM have the best resistance to mixed fuel oil. Acrylic rubber resistant to the best combination of fuel resistance. The blending resistance of the rubber was improved with the increase of the acrylonitrile content. Fluorine rubber with high fluorine content is better for mixed fuel
Adhesive Gasoline / Methanol 85/15 Average Solubility (54 °) /% Gasoline / Ethanol 85/15 Average Solubility (54 °) /%
ECO 92 74
NBR 89 61
VITON A / FPM2601 23-28 16-20
VITON GH 19 15
BITON VI-R-4590 13 13
3 Acidic oxidation Fuelability:
For acidic oxidized fuels, the hydrogen peroxide in the acid oxide fuel can vulcanize the performance of vulcanized rubber, so in the fuel system commonly used Dingqing rubber, chloroprene rubber is difficult to meet the long-term use requirements. Only fluorine-containing elastomers such as fluorine rubber FKM, fluorosilicone rubber FMVQ, fluorinated phosphorus clear and hydrogenated Dingqing rubber performance is better. Ordinary Dingqing rubber compound, can not work in 125 degrees of acidic gasoline for a long time. Only the use of cadmium oxide activated low sulfur - sulfur and white carbon black as the main raw material of Dingqing rubber, in order to better acid gasoline. Increasing the amount of acrylonitrile can reduce the permeability of acidic gasoline.
Resistance to mineral oiliness:
Dingqing rubber is commonly used in mineral oil-resistant rubber. The mineral oil resistance of the Dingqing rubber increases with the increase of the acrylic clear content.
But the high acryl content of Dingqing rubber heat resistance is limited. When the oil temperature reaches 150 degrees, should be used hydrogenated nitrile rubber, fluorine rubber FKM, fluorosilicone rubber FMVQ and acrylic rubber.
Oil temperature reached 150 degrees, the fluorine rubber FKM, fluorine silicone rubber FMVQ the best. But the cost is high, in order to reduce costs, can be incorporated in the fluorine rubber FKM 50% of the following acrylic rubber, and after the vulcanizate performance decreased by no more than 20%.
Acrylic rubber is resistant to mineral oil is better than butyl rubber. Ethylene acrylate rubber rubber rubber heat-resistant oily, better than butyl acrylate rubber.
4 resistant synthetic lubricating oil:
Similar to the principle of compatibility: polar polymer soluble in polar solvents, non-polar polymer dissolved in non-polar solvent, EPDM rubber is hydrogen, in the hydrogen oil in the extreme expansion of silicone rubber in silicone oil , Fluorine rubber in the perfluoro with hydrogen liquid, there are a lot of volume expansion.
5 resistant synthetic hydrogen lubricants:
The oil resistance of Dingqing rubber increased with the increase of acrylonitrile content. The expansion effect of aromatic hydrogen on NBR is greater than that of aliphatic hydrogen. High acrylic clear content of Dingqing rubber, for high hydrogen content of synthetic hydrogen oil. In the acrylic clear content of Dingqing rubber, for low hydrogen content of synthetic hydrogen oil. Low acryl clear content of NBR, for low expansion using synthetic oil such as paraffin oil. Or low temperature flexibility than oil resistance is more important occasions. The use of hydrogenated nitrile rubber can improve heat resistance, ozone resistance and improve resistance to additives. Hydrogenated Dingqing rubber for 140-150 degrees hot oil occasions. Oil resistance heat resistance between the Dingqing rubber and fluorine rubber. Fluorine rubber can withstand 200 degrees of synthetic hydrogen lubricants long-term work. Silicone rubber can withstand 200 degrees of synthetic hydrogen lubricants long-term work. And maintain good flexibility at -60 degrees. It is good for paraffin oil and PAOS. But not resistant to low viscosity synthetic hydrogen oil. Will produce a great expansion. Chlorohydrin rubber can work in the -40 to +120 degrees of synthetic hydrogen lubricants long-term work, with low permeability and good ozone resistance. Defects are the corrosion of the mold and the phenomenon of returning to the original after high temperature aging. Chlorosulfonated polyethylene rubber resistance to synthetic hydrogen-based lubricants, with the increase in chlorine content increased. In the range of -20 to +120 degrees, can only be used in high paraffin mineral oil Kazakhstan PAOS, naphthenic oil and aromatic oil in the expansion of great. Polyurethane rubber AU / EU / also resistant to synthetic hydrogen-based lubricating oil but its compression deformation with temperature (more than 70 degrees) has a tendency to deteriorate. In addition, the hydrolysis resistance is not good.
6 polyalkylene glycol (PAG) synthetic lubricants
Under normal circumstances, the formula appropriate Dingqing rubber, chloroprene rubber, EPDM vulcanized rubber, resistant to PAG synthetic lubricants. But neoprene, EPDM intolerant mineral oil. If the system a little bit of mineral oil, may cause extreme expansion. Fluorine rubber intolerant PAG synthetic lubricants. Resistant organic ester synthetic lubricants, organic ester synthetic lubricants are divided into two categories: dicarboxylic acid esters and polyol esters. Usually use the appropriate coordination of the NBR and fluorine rubber resistant phosphate synthetic lubricants. Silicone rubber can be resistant to phosphate synthesis of lubricating oil, but the physical properties are poor, the use of restricted. EPDM rubber and butyl rubber can only be resistant to pure phosphate, if there is a small amount of mineral oil mixed, will expand. Fluorine rubber is not resistant to phosphate synthetic lubricating oil. Binary ethylene propylene rubber, EPDM rubber and butyl rubber, in the 121 degrees below the phosphate synthesis of lubricants in the long-term work.
Resistant to silicon containing synthetic lubricants.
In general, silicone oil is not easy to cause rubber expansion, but can be rubber in the plasticized out. Non-plasticized styrene butadiene rubber, EPDM rubber, NBR rubber, hydrogenated Dingqing rubber, fluorine rubber are resistant to silicone liquid.
7 Fluorine-containing oil
Poly perfluoroether is a non-flammable liquid and can be used in the temperature range of 230-260. In the known rubber, there is no one in the temperature range of long-term work. EPDM rubber can be used in 100% fluorine-containing oil. Viton can be used at 150 ° C.
8 resistant polyphenylene ether liquid
Polyphenyl ether is the most resistant to radiation of the liquid, and the high temperature and oxidation abnormal stability. EPDM rubber can be used in 100 degrees polyphenyl ether. Viton can be used at 200 ° C. But the fluorine rubber is not resistant to radiation.
9 Chlorine-resistant liquid
Chlorine hydrogen synthesis liquid is non-water-based flame retardant liquid. Fluorine rubber and silicone rubber works well.
Second, the oil-resistant rubber with the system
1. vulcanization system
In general, increasing the cross-linking density can improve the oil resistance of the vulcanizate. In the oxidation of fuel, with peroxide or semi-effective curing system vulcanized Dingqing rubber, sulfur vulcanization than the oil resistance. Peroxide vulcanization system vulcanized Dingqing rubber, the best stability at 40 degrees, 125 degrees in the oxidation of fuel is not ideal. And the use of cadmium oxide and sulfur system to vulcanize the Dingqing rubber, 125 degrees in the oxidation of oil resistance to long-term heat aging performance is better.
2. Filling system and plasticizer
Increase the carbon black and white carbon black can improve the oil resistance softener should be easy to use oil out of the softener. It is best to use low molecular weight polymers such as low molecular weight polyethylene, oxidized polyethylene, polyester plasticizers and liquid rubbers. Polarized, large molecular weight softener or plasticizer, beneficial to oil resistance.
Mainly to add easy to be extracted from the antioxidant. DNP / SANTO FLEX IP / FLEXZONE 3C