The SRT™ measures the swelling ratio of crosslinked polymers as they are placed in a good solvent. From Flory's network theory, the data can be used to calculate the crosslink density, molecular weight between crosslinks, and the number of crosslinks/chain. Download more information below, or go to the applications notes section. The SRT test is in compliance with ASTM F2214-02 “Standard Test Method for In Situ Determination of Network Parameters of Crosslinked Ultra High Molecular Weight Polyethylene (UHMWPE)”. This instrument was developed under an SBIR grant from the NSF.
A test sample is placed in a temperature controlled chamber, which is filled with the solvent. A probe sits on the sample. As the temperature is raised to the desired temperature, a laser micrometer monitors the position of the probe, effectively determining the time-dependent change in height of the sample. Both the kinetics and the steady state swell ratio can be monitored.
The SRT™ is a compact instrument that can easily fit in a fume hood or on a benchtop. Using the custom SRT software, a laptop computer controls the instrument and collects the sample swelling data according to user defined test methods. The software has a data analysis module and calibration subroutine. An add-on software module allows users to program multiple temperature steps during a single run to determine temperature-dependent swelling behaviors.
CPG recently introduced a 3-station SRT (the SRT-3™), which allows simultaneous testing of 3 samples at once, all run from a single computer. The SRT-3 includes an elevating sample chamber for easier sample loading.
For more Information contact CPG using our contact us page.
More information can be found in our application notes section.
A report prepared by the Naval Surface Warfare Center evaluating the SRT-1 is available for download.