Surface modification of EPDM rubber adhesive poly FEP film
|Keywords||FEP film EPDM Solution of sodium - Naphthalene Electron irradiation graft Adhesive strength|
Fluorinated ethylene propylene (FEP) have excellent chemical stability, resistant to acids, alkalis, and strong oxidizing agents, which are widely used in the field of corrosion; ethylene-propylene-diene rubber (EPDM), ethylene, propylene and a small amount of non-conjugated dienes using a solution method or a suspension method and prepared by copolymerizing, has excellent chemical stability, and also has good flexibility after curing, and is widely used as a sealing material. Both composite both excellent performance of anti-corrosion and sealing, used in the chlor-alkali industry the membrane electrolyzer these needs anti-corrosion a sealed heavy anti-corrosion field. However, the FEP as perfluoro polymer material, and polytetrafluoroethylene (PTFE), the same as having a minimal surface polarity, difficult to composite with other materials, so that the composite is required before subjected to surface treatment in advance on the FEP. Surface Modification of fluorine plastic at home and abroad, most are concentrated in the PTFE material for FEP materials is relatively small, the FEP and EPDM bonding rarely reported. Therefore, in this paper, the less of the current domestic and international research, drawing on the basis of the work of our predecessors chose the the FEP film's surface modified chemical and electron irradiation grafting method study to explore the the FEP film's modified mechanism and research adhesive properties of the FEP and the EPDM. Conventional chemical method is used in tetrahydrofuran (THF) as a solvent sodium - naphthyl solution to be processed A method of modifying the surface of the FEP film, having the advantages of simple operation, the effect of rapid and direct, and therefore is widely used in the domestic. However, this method has many deficiencies, such as exposure to the air VALID rapid, rapid response is difficult to control, after processing films exhibited brown, the solvent is volatile with a certain toxicity. To this end, in this paper the use of stable, non-toxic and non-ether-based organic compounds 1,3 - dimethyl -2 - imidazolidinone (DMI) as the solvent system to take Sodium - naphthyl treatment liquid, and the effect of the surface modification were compared with the modification effect of THF solvent used in sodium - naphthyl treatment liquid. The results showed that, except that slight advantage in wettability with THF as a solvent, the treatment liquid, the treatment liquid as a solvent in the processing of the film with EPDM adhesive, DMI handling the adhesive strength of the film and EPDM better than THF as a solvent treatment liquid, the DMI as a solvent, the treatment liquid was significantly superior to the THF as a solvent, the treatment liquid and the treatment liquid to save time. In addition, the paper also studied the impact of the treatment solution concentration on the effect of surface modification, wetting angle and EPDM adhesive strength is found to achieve the best value in the same concentration. By infrared spectral analysis on the modified FEP film that the modified surface of the film portion F atom, are substituted by H atoms produced CH 2 group, which makes the surface of the film properties are improved, thereby forming a good bonding composite with EPDM. Modified FEP film using electron irradiation, the irradiation dose and energy of the electron beam can be generated in the surface of the film an anionic radical, these free radicals are very unstable and can be used with small molecules monoethylenically The organics graft. This article used in an air environment energy of 1.2MeV electron beam on FEP film were the irradiation dose of 300 kGy and 250kGy After irradiation, respectively were grafted with acrylamide and methyl methacrylate. Of the film after the modified XPS analysis, and the modification effect tested. XPS analysis shows that the the FEP film after graft treatment after irradiation and introduced to the surface of the other atoms other than the addition to the C, F, especially in the later and acrylamide grafted film appeared on the surface of the N atom, which shows indeed acrylamide connected grafted to the irradiated surface of the FEP film, and the number of atoms relative ratio F / C decreased from 1.95 before modification to the modified 0.914. The wetting properties of the modified film has been greatly improved, distilled water wetting angle from the surface of the film is reduced to 128.4 ° before the modified modified about 85 °; EPDM adhesive properties has also been a certain degree of improvement, but its adhesive strength is obviously not enough, also need to be studied further.