Background technology
In oil production, oil refining, aerospace, automobile, machinofacture and other industrial production, need a large amount of rubber items, and along with the continuous development of industrialized level, to the requirement of the mechanical property of rubber item and frictional behaviour harshness more and more.
Paracril (NBR) is the multipolymer of divinyl and vinyl cyanide.Owing to contain itrile group in the NBR molecular structure, thereby have oil-proofness preferably.But again because the bond energy of itrile group is big inadequately, content is restricted again, so paracril has certain limitation aspect oil-proofness simultaneously.In addition, as paracril use key areas---the dynamic seal goods also require material to have good tribological property.Variation and the friction of material in medium always begins from the surface; Thereby it is closely related with the performance on surface; People have proposed the method for kinds of surface modification to paracril for this reason, like surface chemical modification (halogenation, sulfonation etc.) and surface physics modification (top coat, plasma technology, surface grafting polymerization etc.).
The halogenation modification is exactly to handle rubber item with the metal halide of fluorine, chlorine, bromine, iodine, interhalogen compound and gas etc.Through factors such as controlling concn, time, temperature; Make rubber surface generation oxidation, addition reaction, form several microns surface-modification structures layers approximately, though can improve the anti-attrition wear resisting property of rubber item to a certain degree to tens micron thick; But because of the modified layer thinner thickness; Hardness improves little, and mechanical property descends to some extent, and these have all influenced its modified effect.Because of halogenation gas toxicity is very strong, very high in addition to processing units and processing requirement.The rubber surface sulfonation uses the vitriol oil or sulfide carbon-carbon bond that it is surperficial to open usually; The carbon atom oxidation generates carbonyl, hydroxyl and carboxyl isopolarity group; The chemically inert surface becomes the surface that polar group is arranged, thereby makes rubber surface activation or polar.Sulfonation can make the rubber surface free energy improve, and it is excellent that wetting property becomes, and helps improving bond strength; But can make rubber surface form trickle slight crack simultaneously, degree of treatment is difficult for grasping during production in enormous quantities, and a large amount of concentrated acid can pollute environment.There are the modified layer thin thickness in surface physics modification technology such as plasma treatment, graft copolymerization, bionical coating etc., are prone to peel off, poor stability, complete processing is loaded down with trivial details wait not enough.
Summary of the invention
Goal of the invention
The present invention is a kind of method of utilizing oxidizing solution to the paracril surface chemical modification; Its objective is the paracril surface microstructure that makes after handling through this method polarization group that changes; Mechanics, tribological property increase substantially, and increase the service life; In addition, the paracril surface modified membrane can not produce with matrix and peel off, and surface-treated do not influence the character of material body, and technology is simple, and is with low cost.
Technical scheme
A kind of method of utilizing oxidizing solution to the paracril surface chemical modification; It is characterized in that: said surface modifying method is the surface oxidation method; Oxidizing solution is for contain the mixing solutions of 30%-60% sulfuric acid, 10%-15% potassiumiodide, 5%-10% Potassium Bromide by mass percentage, and step is following:
(1), surface treatment: paracril is soaked in the mixing solutions that contains 30%-60% sulfuric acid, 10%-15% potassiumiodide, 5%-10% Potassium Bromide at ambient temperature, and soak time is 3-7 days;
(2), drying treatment: the paracril after the above-mentioned surface treatment was positioned in 100-110 ℃ the dry environment 1-2 hour.
Oxidizing solution is for contain the mixing solutions of 50% sulfuric acid, 10% potassiumiodide, 5% Potassium Bromide by mass percentage, and at room temperature soak time is 3 days.
Pending paracril before surface treatment with all need successively to use volume(tric)fraction be that 95% acetone, volume(tric)fraction are that 98% industrial spirit, deionized water are as medium after the surface treatment; In ultrasonic washing instrument, cleaned 3 ~ 7 minutes, and removed paracril surface and oil contaminant and impurity.
In ultrasonic washing instrument, cleaned 5 minutes.
Advantage and effect
The present invention is a kind of method of utilizing oxidizing solution to the paracril surface chemical modification, has the following advantages and beneficial effect:
(1), surface modifying treatment of the present invention, make rubber surface produce carbonyl, hydroxyl and carboxyl isopolarity group, thereby the polarity of making, wellability become excellent, oil-proofness promotes significantly; Hardness increases, and mechanics and tribological property increase substantially;
(2), adopt process for surface oxidation that paracril is carried out surface-treated, will overcome existing surface-treated polarity technology as existence such as plasma treatment, graft copolymerization, bionical coating peel off, deficiency such as poor stability, technology are loaded down with trivial details;
(3), technology of the present invention is simple, with low cost.
Description of drawings
Fig. 1 is the scanning electron microscope image of paracril of being untreated;
Fig. 2 is the scanning electron microscope image of embodiment 1 gained paracril;
Fig. 3 is the scanning electron microscope image of embodiment 2 gained paracrils;
Fig. 4 is the scanning electron microscope image of embodiment 3 gained paracrils;
Fig. 5 is the scanning electron microscope image of embodiment 4 gained paracrils;
Fig. 6 is the scanning electron microscope image of embodiment 5 gained paracrils;
Fig. 7 is the scanning electron microscope image of embodiment 6 gained paracrils;
Fig. 8 is the paracril surface infrared spectrum image that is untreated;
Fig. 9 is embodiment 1 a gained paracril surface infrared spectrum image;
Figure 10 is embodiment 2 gained paracril surface infrared spectrum images;
Figure 11 is embodiment 3 gained paracril surface infrared spectrum images;
Figure 12 is embodiment 4 gained paracril surface infrared spectrum images;
Figure 13 is embodiment 5 gained paracril surface infrared spectrum images;
Figure 14 is embodiment 6 gained paracril surface infrared spectrum images;
Figure 15 be untreated, the hardness value of embodiment 1,2,3 curve over time;
Figure 16 be untreated, the mechanical properties value of embodiment 1,2,3 curve over time;
Figure 17 be untreated, the frictional coefficient of embodiment 1,2,3 curve over time;
Figure 18 be untreated, the abrasion loss of embodiment 1,2,3 curve over time.
Embodiment
Below in conjunction with accompanying drawing and concrete embodiment the present invention is done further explanation:
The acid with strong oxidizing property that the present invention adopts---the vitriol oil is opened the C-C key on paracril surface, and the carbon atom oxidation generates carbonyl, hydroxyl and carboxyl isopolarity group, and the chemically inert surface becomes the polar group surface, thereby makes surface active or polar.Oxidation can make surface free energy improve, and it is excellent that wetting property becomes, and tribological property is improved.
The present invention relates to a kind of method of utilizing oxidizing solution to the paracril surface chemical modification; It is characterized in that: said surface modifying method is the surface oxidation method; Oxidizing solution is the mixing solutions of sulfuric acid, potassiumiodide, Potassium Bromide, contains 30%-60% sulfuric acid, 10%-15% potassiumiodide, 5%-10% Potassium Bromide by mass percentage, all the other are deionized water; Concrete steps are following:
(1), surface treatment: paracril is soaked at ambient temperature contains 30%-60% sulfuric acid (H
2SO
4, analytical pure is the preparation of 98% the vitriol oil by the solute massfraction), in the mixing solutions of 10%-15% potassiumiodide (KI, analytical pure), 5%-10% Potassium Bromide (KBr, analytical pure), soak time is 3-7 days;
(2), drying treatment: the paracril after the above-mentioned surface treatment was positioned in 100-110 ℃ the dry environment 1-2 hour.
Above-mentioned oxidizing solution is for contain the mixing solutions of 50% sulfuric acid, 10% potassiumiodide, 5% Potassium Bromide by mass percentage, and at room temperature soak time is 3 days, and this moment, effect was preferable.
Above-mentioned pending paracril before surface treatment with surface treatment after (promptly with oxidizing solution soak forward and backward) all to need successively to use respectively concentration (volume(tric)fraction) be that 95% acetone, concentration (volume(tric)fraction) they are that 98% industrial spirit, deionized water are as medium; In ultrasonic washing instrument, clean and (promptly used the acetone of volume(tric)fraction 95% in ultrasonic washing instrument, to clean 3 ~ 7 minutes in 3 ~ 7 minutes as medium; Using volume(tric)fraction again is that 98% industrial spirit cleaned in ultrasonic washing instrument 3 ~ 7 minutes as medium; Use deionized water in ultrasonic washing instrument, to clean 3 ~ 7 minutes at last) as medium; Scavenging period was advisable with about 5 minutes; Removing paracril surface and oil contaminant and other impurity, thereby guarantee the degree of cleaning of pending paracril.
Embodiment 1
Paracril is soaked in the mixing solutions that contains 50% sulfuric acid, 10% potassiumiodide, 5% Potassium Bromide (mass percent), and at room temperature soak time is 3 days; Be positioned over then in 100 ℃ the dry environment 1 hour, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 5 minutes in ultrasonic washing instrument.
Embodiment 2
Paracril is soaked in the mixing solutions that contains 50% sulfuric acid, 10% potassiumiodide, 5% Potassium Bromide (mass percent), and at room temperature soak time is 5 days; Be positioned over then in 100 ℃ the dry environment 1 hour, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 5 minutes in ultrasonic washing instrument.
Embodiment 3
Paracril is soaked in the mixing solutions that contains 50% sulfuric acid, 10% potassiumiodide, 5% Potassium Bromide (mass percent), and at room temperature soak time is 7 days; Be positioned over then in 100 ℃ the dry environment 1 hour, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 5 minutes in ultrasonic washing instrument.
Embodiment 4
Paracril is soaked in the mixing solutions that contains 30% sulfuric acid, 15% potassiumiodide, 10% Potassium Bromide (mass percent), and at room temperature soak time is 6 days; Be positioned over then in 100 ℃ the dry environment 1 hour, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 3 minutes in ultrasonic washing instrument.
Embodiment 5
Paracril is soaked in the mixing solutions that contains 60% sulfuric acid, 12% potassiumiodide, 8% Potassium Bromide (mass percent), and at room temperature soak time is 4 days; Be positioned over then in 110 ℃ the dry environment 2 hours, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 7 minutes in ultrasonic washing instrument.
Embodiment 6
Paracril is soaked in the mixing solutions that contains 40% sulfuric acid, 13% potassiumiodide, 7% Potassium Bromide (mass percent), and at room temperature soak time is 7 days; Be positioned over then in 105 ℃ the dry environment 1.5 hours, and can obtain hardness height, polarity paracril that anti-friction wear-resistant property is good.Wherein paracril before surface treatment with surface treatment after all need successively with concentration (volume(tric)fraction) be 95% acetone, concentration (volume(tric)fraction) be 98% industrial spirit and deionized water as medium, cleaning is 5 minutes in ultrasonic washing instrument.
The modified butadiene acrylonitrile rubber of the foregoing description 1 ~ 6 gained is carried out various performance tests, and the result is following:
Extremely shown in Figure 7 like Fig. 1; The paracril of above-mentioned six embodiment gained is analyzed with ESEM, under 5000 times of magnifications, observed, and compare with the paracril that does not carry out surface-treated; Find that surface topography takes place obviously to change; Along with the prolongation of soak time, the surface is Paint Gloss, shows that the wellability of rubber becomes excellent.
Extremely shown in Figure 14 like Fig. 8; The paracril of above-mentioned six embodiment gained is observed with ir spectra; And compare with the paracril that does not carry out surface-treated, find that surface microstructure takes place obviously to change, along with the prolongation of soak time; Polar group increases, and shows that the rubber oil-proofness becomes excellent.
Shown in figure 15, hardness test is carried out on the paracril surface of the foregoing description 1,2,3 gained, adopt LX-A type durometer.And compare with the paracril that does not carry out surface-treated, find that hardness takes place obviously to change, along with the prolongation of soak time, hardness increases gradually.
Shown in figure 16; Mechanical test is carried out on the paracril surface of the foregoing description 1,2,3 gained; Press the GB/T528-92 standard, sample is cut to dumb-bell shape, the tensile property of the TCS-2000 type pulling force aircraft measurements sample of High Speed Rail Testing Instruments ltd in Taiwan; Gauge length 20mm, draw speed are 500mm/min.And compare with the paracril that does not carry out surface-treated, find that mechanical property takes place obviously to change, along with the prolongation of soak time, intensity increases gradually.
Shown in figure 17; The frictional coefficient test is carried out on the paracril surface of the foregoing description 1,2,3 gained; Use the reciprocation type microcomputer control wear test machine of Jinan general industry mechanical & electrical technology ltd that paracril is carried out dry friction and wear experiment, load 98N, reciprocating frequence 1Hz; Reciprocal distance 0.02m, wearing-in period 3600s.And compare with the paracril that does not carry out surface-treated, find that frictional coefficient takes place obviously to change, along with the prolongation of soak time, frictional coefficient reduces gradually.
Shown in figure 18; The abrasion loss test is carried out on the paracril surface of the foregoing description 1,2,3 gained; Use the reciprocation type microcomputer control wear test machine of Jinan general industry mechanical & electrical technology ltd that paracril is carried out dry friction and wear experiment, load 98N, reciprocating frequence 1Hz; Reciprocal distance 0.02m, wearing-in period 3600s.And compare with the paracril that does not carry out surface-treated, find that abrasion loss takes place obviously to change, along with the prolongation of soak time, abrasion loss reduces gradually.
Table 1 is the test value of the various performances of embodiment 4,5,6, and is as shown in table 1, and hardness test, frictional coefficient test, abrasion loss test are carried out in the paracril surface of the foregoing description 4,5,6 gained; And compare with the paracril that does not carry out surface-treated; Discovery is along with the oxidation susceptibility enhancing of solution and the prolongation of soak time, and each test performance takes place obviously to improve, and hardness increases; Frictional coefficient reduces, and abrasion loss reduces.
Following table 1 is the test value of the various performances of embodiment 4,5,6.
The present invention adopts the mixing solutions oxidation style, and each composition is processed oxidizing solution according to a certain percentage.This method makes rubber surface generation oxidation, addition reaction, forms millimetre-sized surface-modification structures layer, and its hardness, mechanical property, tribological property are increased substantially, and prolongs its work-ing life, enlarges its scope of application.In addition, the paracril surface modified membrane can not produce with matrix and peel off, and surface-treated do not influence the character of material body, and technology is simple, and is with low cost.