I need to determine the Mw of polydimethylsiloxane polymer by SEC. I determined the Mw of polyphenylsiloxane by SEC as phenyl groups absorb in UV-spectrum. For methyl groups other detector is needed. Could anyone suggest one?
Answers were provided to you as you already asked this question before (https://www.researchgate.net/post/Hi_everyone_What_kind_of_chromatography_is_better_to_use_SEC_or_HPLC_to_analyse_polymers_with_molecular_weight_of_about_6000Da?)
PDMS can be run on SDV (styrene divinyl benzene) columns typically in toluene using RI-detection.
Since PDMS is isorefractive in THF, you will need to use toluene as solvent.
Regards
Wolfgang
MW of all polymers can be detected by RI detector if they are soluble in appropriate solvents.
It really depends on the type of sample and the expected concentration. RI is used for 'neat' PDMS samples since you can only detect ~0.1% (1000 ppm).
ELSD is used for much lower concentrations but it depends on the specificity of the method (other stuff will be detected).
- Badges
- Science topic