VAPOR PRESSURE OSMOMETRY AS A MEANS OF DETERMINING POLYMER MOLECULAR WEIGHTS
Abstract
The application of vapor pressure osmometry to the determination of molecular weights of polymers has been investigated. The principles of the theory and operation of a commercially available vapor pressure osmometer are described and the effects of reading time and drop size are analyzed. It is shown that, for calibration with benzil in dihydroperfluorobutanol at 65 C, resistance readings reached a maximum after three to four minutes and then declined slowly. Extrapolation to zero time was essential. It is further shown that drop size variations measurably effect the resistances making it desirable to account for this effect by using a standard drop size and correcting the results accordingly. Some results obtained for the measurement of molecular weights of samples of polyhexamethylene sebacamide are quoted, and a discussion of potential errors and proper experimental procedures for minimum error is given.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1966
- Accession Number
- AD0487755
Entities
People
- A. C. Meeks
- Ivan J. Goldfarb
Organizations
- Air Force Research Laboratory