Polymer Plating Research Articles

Direct Joining between Ethylene Propylene Rubber and Cast Iron with Functional Polymeric Nanofilm

A novel technique was developed for direct joining between ethylene propylene rubber and high ductile spheroidal-graphite cast iron using functional polymeric nanofilm without any adhesive. The functional polymeric nanofilm was created on the surface of cast iron by means of polymer plating with a synthesized organic compound of 6-diallylamino-1,3,5-triazine-2,4-dithiol monosodium salt. High peel strength joints of the rubber to polymer-plated cast iron were achieved by adding an accelerating agent of perhexane 3M under crosslinking condition of 418 K for 7 min. As the thickness of polymeric nanofilm was around 8.5 nm, peel strength of the joints was high to 8.9 kN/m and its broken-out section was rubber cohesive failure with 100% rubber coverage. Rubber/cast iron joints possessed good heat-resistant property. The film thickness and perhexane content had large effects on water resistance of joints. It is considered that high joining property results from chemical bond at interface between polymer-plated cast iron and rubber chain.

Polymer Plating of 6-(N-Allyl-1,1,2,2- Tetrahydroperfluorodecyl)Amino-1,3,5- Trazine-2,4-Dithiol Monosodium on Aluminum in Magnetic Field and its Electrostatic Capacity

Polymer plating of 6-(N-Allyl-1,1,2,2-tetrahydro perfluoro decyl) amino-1,3,5-trazine-2,4-dithiol monosodium (ATP) on aluminum was investigated in the presence and absence of magnetic field and a film capacitor was fabricated using the polymer film deposited on aluminum. Polymer plating of ATP was performed in NaNO/sub 2/ aqueous solution at 5/spl deg/C, with film thickness found to increase proportional to the square root of plating time according to the parabolic law, both in the presence and absence of magnetic field. Polymer films were considerably thicker when fabricated in the presence of a magnetic field than that in the absence. The rate of film formation, however, was slightly higher in the presence of a magnetic field. For ATP polymer plating at a current density of 2 A/cm/sup 2/, the potential applied during film deposition increased with plating time and was considerably higher in the presence of a magnetic field. This shows that the presence of magnetic field leads to the formation of insulating polymer films. From FT-IR results, polymer films were found to be more closely packed and highly ordered in the presence of a magnetic field than in the absence. Fabricating polymer film in the presence of a magnetic field provides higher electrostatic capacitance than in the absence of a magnetic field. Electrostatic capacitance was found to increase with magnetic flux density. Polymer films having dielectric constants of 200 to 450 were obtained suggesting organic ferroelectrics.

Electropolymerization of Monosodium Salts of Triazine Thiols in Magnetic Field

The effect of magnetic field on the polymer plating of the 6-substituted groups triazine natrium salts such as 6-(dibutylamino)-1,3,5-triazine-4,6-dithiol monosodium salt, 6-(dihexylamino)-1,3,5-triazine-4,6-dithiol monosodium salt stepwise to 6-(dioctadecylamino)-1,3,5-triazine-4,6-dithiol monosodium salt on stainless surfaces were studied. The electropolymerizations were carried out in a magnetic field of superconducting magnet at varying magnetic flux density 0-5 T. The working (stainless) electrodes were placed parallel or perpendicular to the direction of the external magnetic field. The electropolymerization was conducted without agitation. The supporting electrolyte Na/sub 2/CO/sub 3/ in concentration of 0.1 M was used. The increase of polymerization yield on surface of stainless electrodes was examined, comparing a chronopotentiometric polymerization in the magnetic field with nonmagnetic polymerization. The evaluation of magnetic field orientation versus working electrode showed that magnetohydrodynamic effect (MHD) at parallel configuration of electrodes to the magnetic field occurred. MHD affected the convection in solution of monomers and consequently the yield of reaction. Effect of current density, polymerization time and monomer concentration on the weight of polymerized film under various magnetic flux density were examined. Results showed that the effect of magnetic field on the electropolymerization depends on its density.

Development of polymer‐molding‐releasing metal mold surfaces with perfluorinated‐group‐containing polymer plating

AbstractThe polymer‐molding‐releasing properties of metal molds were found to be related to the following factors: (1) interfacial chemical bonding between the surfaces of polymers and metal molds and (2) a friction force or friction coefficient between polar substances and/or low‐molecular‐weight components in the polymers and physical factors on mold surfaces. We theoretically and experimentally confirmed that metal molds with good polymer‐molding‐releasing properties had very small surface free energies. We also proved that the surface free energies in the resulting polymer moldings were lower than before shaping. The molding releasing properties improved with decreasing friction force and friction coefficient between the surface of polymers and metal molds and with decreasing surface free energy. To obtain metal molds with lower surface free energies, we developed a polymer plating method with perfluorinated‐group‐containing triazine dithiol. The Metal mold treated by polymer plating had lower critical surface tension (7.5 mJ/m2) than Teflon (18 mJ/m2), indicating that the surface consisted of CF3− groups. The treated mold showed excellent durability in its releasing properties, which was better than that of the untreated mold. This technique was developed for the production of molds for the Fθ lens and the naturally bright focusing screen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2549–2556, 2003

Electrochemical Reaction in the Polymer Plating of Triazine Dithiols

The polymer plating of 6-substituted groups-1,3,5-triazine-2,4-dithiol on metal electrodes in organic solvents was studied with respect to the effect of triazine dithiols, metal electrodes, and organic solvents on electrochemi-cal reactions. Cyclic voltammograms of 6-dioctylamino-1,3,5-triazine-2,4-dithiol (DO) on Pt plate in an acetonitrile solution of tetrabutyl ammonium hexafluoro phosphate revealed three peaks due to oxidation and reduction. The substituted groups in triazine dithiols were found to have a large influence on the reaction in polymer plating as well as their dissociation constant and oxidation potential. The type of metal electrodes was also found to affect the reactions significantly, attributable to differences in oxidation potential. Solvents accelerated the formation of radical cations for DO and bithiyl radicals for DO monosodium salt. As an overall mechanism, it was determined that thin polymer film is formed by the coupling of radical cations formed by electrochemical reaction of DO.

有機めっき処理金属とゴムとの直接架橋接着に関する研究（第４報）有機めっき処理スチールと過酸化物架橋系ＥＰＤＭとの直接架橋接着

It was found recently that ethylene-propylene diene rubber (EPDM) compounded with peroxide could be adhered directly to steel during vulcanization after a polymer plating of steel in 6-diallylamino-1, 3, 5-triazine-2, 4-dithiol monosodium (DAN)/sodium carbonate aqueous solution. The rubber adhesion of the polymer plated steel is studied here with emphasis on the effect of the polymer film thickness and the contents of the compounding ingredients, such as HAF carbon black, process oil and peroxide. In order to evaluate the effect of the compounding ingredients, a three variable central composite designed experiment based on a Box-Wilson response surface methodology is employed. The results show that the thickness of the polymer plating film should be controlled in an optimum range from about 20nm to 200nm in order to obtain enough peel strength of adherend. On the other hand, the peel strength is affected by carbon black, process oil and peroxide contents, and high interactions among these factors are observed. These factors show their respective optimum contents, which is explained as a result of the balance of reactions between peroxide/rubber and peroxide/polymer plating film occurred at the adhesion interface during vulcanization. The adherends under the optimum compounding show excellent heat aging resistance, moisture aging resistance, and water aging resistance.

Accelerating effect of NaNO2 on the polymer plating of 6‐substituted‐1,3,5‐triazine‐2,4‐dithiol mono sodium salts

AbstractOrganic polymer plating properties of 6‐substituted‐1,3,5‐triazine‐2,4‐dithiol mono sodium salts were investigated in the presence of various supporting electrolytes. Among these, the NaNO2 supporting electrolyte greatly accelerated the film formation rate in polymer plating. The accelerating effect of NaNO2 was further confirmed by comparing plating potentials in the presence of NaNO2 and Na2CO3. The potentiostatic polymer plating of DAN in the presence of the NaNO2 supporting electrolyte took place in the potential range of 1.65–1.8 V (compared against saturated calomel electrode reference). Film formation was influenced by such factors as the pH of solution and both the chemical structure and the concentration of triazine dithiol. In polymer platings, NO anions are thought to be electrochemically oxidized to yield NO radicals and these radicals react with DAN to yield new thiyl radicals. The thiyl radicals in the DAN molecules couple with each other by means of disulfide bonds, resulting in the growth of polymer film. Organic polymer plating films are shown to contain disulfide bonds, monosulfide bonds obtained by the reaction between allyl groups and thiyl radicals, and network chains. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2300–2309, 2001

有機めっき処理金属とゴムとの直接加硫接着に関する研究 （第２報） 有機めっき処理マグネシウム合金ＡＺ９１Ｄとアクリルゴムとの直接加硫接着

The non-adhesive and corrosive magnesium alloy AZ91D can be adhered directly to acrylic rubber (ACM) during vulcanization through the polymer plating of AZ91D in 2-diallylamino-1, 3, 5-triazine-4, 6-dithiol monosodium (DAN) aqueous solutions. The triazine thiol film can be plated stably onto AZ91D only in the strong base solutions, though the anodic oxides such as Mg(OH)2 and MgO are formed simultaneously in the polymer plating process. The peel strength of the adherend of the polymer plated AZ91D to ACM is dependent strongly upon the absolute and relative content of the triazine thiol composition in the plating layer. Increasing the concentration of NaOH in the electrolytic solution, the composition ratio of triazine thiol to anodic oxides in the plating layer decreases and thereby the peel strength of the adherend decreases accordingly. Adding Na2CO3 into the electrolytic solution containing low concentration of NaOH, the composition ratio of triazine thiol to anodic oxides, and consequently the peel strength of the adherend can be increased. Moreover, in order to obtain adherend with high peel strength, AZ91D should be polymer plated in the optimum range of current density and time, and at low temperature under 20°C. The adherend has good heat aging resistance and excellent oil resistance.

有機めっき処理金属とゴムとの直接加硫接着に関する研究 （第３報） 有機めっき処理金属とゴムとの直接加硫接着性に及ぼす有機めっき被膜構造の影響

Thin organic films formed on stainless steel SUS 304 BA substrates by polymer plating of different 6-substituted-1, 3, 5-triazine-2, 4-dithiol monosodium (RTDN) monomers were characterized using reflection absorption Fourier transform infrared spectroscopy (RAS FT-IR), specular reflection FT-IR, transmission FT-IR spectroscopy, Raman spectroscopy, and electron spectroscopy for chemical analysis (ESCA). The insoluble fractions of thin organic films in tetrahydrofuran (THF) were measured representing the cohesive strength or crosslinking extent of the films. RTDN monomers were electrochemically polymerized to triazine thiol polymers containing S-S bonds on the metal substrates through polymer plating treatment. The average orientation of the triazine rings and substituted groups in films was anisotropic and perpendicular to the substrates. The thin organic films were covalently bound to substrates through the S-Fe, or S-Cr bonds. The effect of film crosslinking extent and reactivity to rubber molecules or curing agents on the adhesion strength of adherend of polymer plated metal to peroxide cure system ethylene-propylene rubber (EPDM) was elucidated. In order to obtain high adhesion strength, it is necessary for the thin organic film to have three properties showed as follows: (1) to form chemical bonding at the film/metal interface, (2) to form chemical bonding at the film/rubber interface, (3) to have enough film cohesive strength. The thin organic film by the polymer plating of RTDN monomer just like 6-diallylamino -1, 3, 5-triazine-2, 4-dithiol monosodium (DAN) acts as a reinforcing layer at the interface between metal and rubber to improve the adhesion strength of the adherend.

有機めっき処理金属とアクリルゴムとの直接加硫接着

A novel technique for the direct adhesion between acrylic rubber (ACM) and metals, such as iron, nickel and stainless steel SUS 304 during vulcanization was developed. The metals are first plated with thin polymer films through the electrochemical polymerization of 6-diallylamino-1, 3, 5-triazine-2, 4-dithiol monosodium (DAN), and then adhered directly to acrylic rubber during vulcanization. The modification of metal surface has been also called polymer plating compared with the traditional metal electroplating. The thickness of the polymer film has a significant effect on the peel strength of the adherend of polymer plated metal to ACM. The peel strength of the adherend increases rapidly with the film thickness within about 25nm, and beyond the thickness, maintains enough peel strength showing the rubber cohesive failure with 100% rubber coverage. The peel strength of the adherends decreases with the increase of the amounts of the curing agents but shows rubber cohesive failure in the normal compounding amounts. The curing temperature and time of the rubber have only a little effect on the peel strength of the adherend. The adherend has excellent heat aging resistance and oil resistance.

Polymer Plating of 6-Substituted-1, 3, 5-Triazine-2, 4-Dithiols on Magnesium Alloys and Applications of the Plated Alloys

Polymer plating of triazine dithiols on magnesium alloys and applications of the plated alloys were investigated, focusing on important factors for improvement of corrosion resistance and adhesion properties of magnesium alloys. Three kinds of triazine dithiols; 6-dihexylamino-1,3,5-triazine-2,4-dithiol monosodium salts (DHN), 6-diallylamino-1,3,5-triazine-2,4-dithiols (DAN), and 6-mercapto-1,3,5-triazine-2 4-dithiol (TTN), were prepared for imparting functions such as corrosion resistance and direct adhesion to magnesium alloys. In polymer plating of DHN, film thickness initially increases with current density, reaches a maximum at I A/m 2 , and then decreases. Film thickness initially increases with DHN concentration, reaches a maximum at 8 mol/m 3 , and then decreases. Polymer plating of DAN yields good polymer film on magnesium in terms of adhesion when 10 mol/m 3 NaOH/Na 2 CO 3 aqueous solution is used as an electrolytic solution. An 8 mol/m 3 DHN aqueous solution was found to impart the best corrosion resistance for reaction resistance and corrosion current density. In direct adhesion of EPDM to polymer-plated magnesium alloys, a film thickness of near 100 nm imparts the highest peel strength. In injection molding adhesion of PPS polymer to polymer-plated magnesium alloys, high tensile shear strength is obtained when mold temperature exceeds 140°C.

Effect of Triazine Dithiols on the Polymer Plating of Magnesium Alloys

2- Substituted (R)-1,3,5- triazine-4,6-dithiols (triazine dithiols ) with different alkyl chain lengths as substituents were prepared by the reaction of cyanuric chloride, dialkylamines and NaSH. Triazine dithiols were found to polymerize electrochemically on magnesium alloy (AZ91) plates. This method for coating metals is called polymer plating In the polymer plating of triazine dithiols on magnesium alloy plates, an aqueous 1M-NaOH solution was selected for the formation of polymer films and the suppression of side reactions. To select the optimal conditions for the formation of polymer films and the suppression of side reactions, plating factors such as the electrolyte, temperature, concentration, potential and current density were investigated. The films formed were composed of a polymer film, Mg(OH)2 and MgO, and the chemical structure of the films is discussed. The contact angle of the polymer films increased with the length of the alkyl chain and became constant for a chain length of six carbons. Polymer films with a 98° contact angle had a top surface completely covered all by CH3 - groups and not by - CH2- The alkyl chains were oriented in the vertical direction and were closely packed. Among the five polymer films studied real impedance (Rp) was the largest at about 27,000 Ω cm -2 - for the polymer film with a (C6H13)2N- subustituent The icorr of this polymer film was 5x 10 -7 A cm -2 2 The outstanding corrosion resistance of polymer film with a (C6H13)2N-subustituent is thought to result from the alkyl chains in the film that were highly oriented and closely packed.

６‐ジアリルアミノ‐１，３，５‐トリアジン‐２，４‐ジチオールの有機めっきにおよぽすＮａＮＯ２の促進作用

Organic polymer plating properties of 6-diallylamino-1, 3, 5-triazine-2, 4-dithiol monosodium (DAN) were studied for NaNO2 supporting electrolytes. Supporting electrolytes cause polymer film to form or not. NaNO2 electrolytes particularly accelerated the formation rate of polymer plating. The accelerating effect of NaNO2 was confirmed comparing plating potentials in the presence of NaNO2 and NaCO3. NO2- anions are electrochemically oxidized to yield NO2·radicals that react with DAN to yield thiyl radicals. DAN thilyl radicals between molecules, yielding disulfide bonds that grows into polymer films. Organic polymer plating films contained disulfide and monosulfide bonds produced by the reaction between allyl groups and thiyl radicals and network chains.

Polymer Plating of 2-Dioctylamino-1,3,5-triazine-4,6-dithiol to Magnesium Alloys

Polymer Plating of 2-Dioctylamino-1,3,5-triazine-4,6-dithiol to Magnesium Alloys