A NEW METHOD FOR THE RAPID DETERMINATION OF GLASS TRANSITION TEMPERATURES,
Abstract
The method proposed is based on the response of a strain sensor (which is in intimate contact with the material) to the changes occurring in the material as it passes through the glass transition. While it cannot be used with powdery samples, it is otherwise restricted only by the temperature characteristics of the strain gauge, and can thus be used on any amorphous material with which the gauge can be brought into very intimate contact. There are two different methods of applying the strain gauge to the material. For systems in which the viscosity is sufficiently low (less than 100 poises) at temperatures at which the material is stable (this immediately excludes some high polymers) the gauge, together with a small thermocouple, is simply immersed in the liquid, and the container (usually a simple test tube) is cooled to below the Tg value. By this method, the Tg values of methyl methacrylate, glucose, selenium, sulfur and glycerine were determined. Whenever the embedding of the gauge and thermocouple is not convenient (due to possible decomposition of the material at the high temperatures needed to achieve low enough viscosities), the strain gauge can be glued to the material, be it a rubber or a glass, by means of epoxy cement or any other suitable glue, and again any convenient heating or cooling method employed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1963
- Accession Number
- AD0427332
Entities
People
- A. Eisenberg
- E. Rovira
Organizations
- University of California, Los Angeles