7 different HNBR compounds are produced and to understand the chemical resistance of these compounds several liquid immersion tests at elevated temperatures (ageing) have been conducted and checked for its change in the hardness, tensile strength and elongation at break before and after the ageing. While there has been noticable changes in the above menttioned properties, few compounds show less variation while the others show huge variation in the properties. Therefore, to investigate further I would like to determine the cross link density of all the compounds and correlate this with their performance with the ageing. I have the results of cure charateristic curve (MDR-2000) for all the compounds and would like to know the correlation of this curve with the crosslink density.
If you have MDR data at different temperatures, there are many well established empirical models.. many papers on this topic especially in RCT.. ex: 10.5254/rct.14.85968
One can calculate the crosslink density of rubber using MDR cure curves by DIN 53529 (1983) procedures. but this procedure works well with unfilled rubber system. If the rubber is highly filled it does not work due to the filler-polymer interaction and filler-filler interaction effect. In this case better to go with Flory-Rhener swelling concepts and low field proton NMR experiments.
Crosslink density is calculated as per the Flory-Rehner equation
Reference.
[1] B. Ellis, and G.N. Welding, Rubber Chem. Technol., 37,571 (1964).
[2] P. J. Flory, J. Chem.Phys., 18, 108 (1950).
[3] K.K.Sasidharan, R.Alex and Thomas Kurian, Rubber Chemistry and Technology, Vol.87, No.2, pp250-263 (2014)
Hi
You can get an overall idea about the quantification of cross-link density in the following article.
Article ENTANGLED NETWORK INFLUENCED BY CARBON BLACK IN SOLUTION SBR...
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys
- Steel