By exposing a micro cantilever which is composed by different two materials to vapor atmosphere, slight deflection of micro cantilever due to humidity change can be observed. As increasing relative humidity, the micro cantilever composed by Au and Si3N4 multi layer films bends slightly toward the side of Si3N4 thin film. When the both sides of micro cantilever is composed by the same material, no deflection can be detected. The micro cantilever has a differential sensitivity to moisture adsorption on to each surface of the micro cantilever. Based on activation energy at nucleation of moisture cluster, deflection mechanism of the micro cantilever can be analyzed. It is capable to apply the micro cantilever as a humidity sensor.

View full abstract

By using the laser-beam measuring equipment, the system to obtain the retardation spectrum of the pressure sensitive adhesive was completed. The exponential regression of the measurement data that contained the flow term was done. Then the smoothed measured data was numerically differentiated, and the retardation spectrum was obtained. In polymer/tackifier pressure sensitive adhesive system, the effect of the chemical structure and of the softening point of the tackifier resin were investigated. From the investigation, it becomes clear that the short time region of the retardation spectrum shape depends on the chemical structure of the tackifier, while the long time region of it depends on the softening point. This is the same as a past investigated result to base polymer. The mechanical properties of the pressure sensitive adhesives are clarified by studying the retardation spectrum. And this method will back up to design the pressure sensitive adhesive.

View full abstract

The influence of the addition of NaOH on the modification of the Al(OH)3 surface with g-mercaptopropyltrimethoxysilane (MGPS) was investigated. The Al(OH)3 particles were modified with MGPS in methanol solution containing until 0.1wt% of NaOH or NaNO3 for Al(OH)3. Vulcanized EPDM filled with MGPS-modified Al(OH)3 was prepared by mixing roll and compression press. The influence of the interfacial structure in vulcanized EPDM on mechanical properties of vulcanizates filled with the modified Al(OH)3 was discussed. The amount of detected MGPS on Al(OH)3 surface increased with increasing NaOH concentration the surfaces, whereas it was not so influenced by the addition of NaNO3. Tensile strength of vulcanized EPDM increased with increasing the amount of detected MGPS on the surfaces, but it decreased with increasing in NaOH concentration of the surfaces. Three hundred % Modulus (M300) of vulcanized EPDM specimens prepared in the presence of NaNO3 (0.1wt%) and NaOH (<0.04wt%) was improved by modification of Al(OH)3 with MGPS. However, M300 of vulcanized EPDM specimens prepared in the presence of 0.1wt% NaOH was not markedly improved.

View full abstract