화학공학소재연구정보센터
KAGAKU KOGAKU RONBUNSHU, Vol.23, No.2, 272-279, 1997
Measurement of surface tensions for straight and thermal degradation asphalts
This paper examines the close relationship which exist between asphalt temperature and surface tension in order to learn more about the surface chemistry of asphaltic materials and various kinds of aggregate materials. The relationship which is basically indicative of one of the most important properties of the asphalt can be established by measuring the contact angle of the asphalt meniscus formed in response to polyethylene.The well-known relationship between temperatures and surface tensions of alpha-bromonaphthalene has enabled the surface tension of polyethylene to be obtained by repeating the above procedure. Furthermore, it has been found that both the total surface energy and the surface entropy remain almost the same throughout the measurement. Surface tension and the surface entropy at a temperature of 293 K were found to be about 10(-2)N/m and about one order higher than the respective ones obtained by Saal. Asphalt specimens with a penetration of 60-80 are used in a thermal degradation test. Special attention is paid to what influence was time exerted on thermal degradation of the asphalt surface. It is concluded that the total surface energy and the surface entropy increase in all cases where thermal degradation is in progress.