| 초록 |
The effect of curing temperature on adhesion characteristics was investigated. Thecuring temperature of rubber compounds was varied from 130 oC to 190 oC interval of 15 oC.Curing time of adhesion samples was determined by T90 time of OD rheometer atcorresponding temperature. The pullout force of unaged adhesion sample decreased withincreasing curing temperature (Table 1). The pullout force of thermally aged adhesion sampleappeared to be same trend as that of unaged adhesion sample. The rubber coverage ofthermally aged adhesion sample is not indedendent of curing temperature except to lowcoverage of adhesion sample cured at 190 oC. The decrease in pullout force for unaged andthermally aged adhesion sample with increasing curing temperature can be explained as thephysical properties of vulcanizate, especially tensile strength. The volcanoe curve of pulloutforce of humidly aged adhesion sample with increasing curing temperature suggested thatcuring temperature affected not only physical properties of vulcanizate but also the formationand degradation of adhesion layer forming during curing and humid aging. The good flow ofrubber compound at lower curing temperature can not be explained as this phenomenum. The adhesion layer of entact adhesion layer for simulation adhesion sample composedof brass film on glass plate and rubber compound was analyzed by Auger ElectronSpectroscopy and this argon sputtering. The depth profile of adhesion layer with unagedadhesion sample varying curing temperature did not show noticeably change except ZnO peakat adhesion interface. The higher curing temperature of adhesion sample, the more sharp ZnOpeak at adhesion interface. The dezincification was occurred very fast very in higher curingtemperature. The depth profile of humidly aged adhesion sample appeared to be very differentpattern from that of unaged adhesion sample. The sulfur signal thickened during hunid agingof adhesion sample especially cured 130 oC and 145 oC. Over 175 oC of curing temperature,adhesion layer did not grow significantly. In humidly aged adhesion sample cured at 130 oC,zinc peak did not detect noticeably but sulfur peak and copper peak broadened and intensified.The lower curing temperature resulted in the formation of less ZnO regardedas copper-diffusion barrier at adhesion interface. Therefore, excessive copper sulfide formedand adhesion interface can be deformed easily under humid condition. In humidly agedadhesion sample cured over 175 oC, insignificant growth and deformation of adhesion layerresulted from the thick ZnO at adhesion interface and the lack flow of rubber compound intoadhesion interface. Therefore, optimum curing temperature should be determined in views ofthe flow of rubber compound and adhesion interface balanced Cu, Zn, S and O.
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