|Sammler, R - DOW CHEMICAL|
Submitted to: Rheologica Acta
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 23, 2000
Publication Date: N/A
Interpretive Summary: Opening new, value-added applications for the utilization of agricultural materials is the long-term goal of this research project. One of the most cost-effective methods to develop materials for new applications is to combine, or blend, two or more materials together. The physical properties and processing behavior of the resulting blends are controlled, in part, by the adhesion of the components which, in turn, is related to the surface properties and the interfacial tension between the components. There is little information available in the literature on the surface properties of polymers. In this work the methodology to be used in these studies has been developed using pairs of commercial polymers. The procedures are applicable to the investigation of biological polymers of agricultural significance (starches, proteins) and can be utilized to investigate and understand the effects of polymer processing variables such as pressure and temperature on the properties of blends of biological or agricultural polymers in new blend applications.
Technical Abstract: The effect of temperature on the interfacial tension for PS/PMMA, PS/PE, and PMMA/PE was measured using the imbedded fiber retraction method. Interfacial tensions for PS/PMMA, PS/PE, and PMMA/PE were measured over temperature ranges of 160-250, 140-220, and 140-220 deg C, respectively. The interfacial tension was found to follow a dependence of 3.6-0.013T, 7.6-0.015T, and 11.8-0.017T dyn/cm for PS/PMMA, PS/PE, and PMMA/PE, respectively. Comparison of the data with the mean field theory of Helfand and Sapse were made; however, a simple linear fit to the data described the temperature dependence as well as the predictions of the mean field theory.