Relating the performance and properties of rubber products and rubber composites to their chemical microstructure and the chemistry of their production.
A variety of techniques have been developed for:
Determining both total crosslink densities and the levels of the different types of crosslink.
Chemical analysis of the fate of the components of the cure system.
Determination of the distribution of crosslinks between the components of blends of rubbers (in particular using a swollen-state NMR spectroscopy technique developed in-house);
Evaluation of the interactions between rubbers in blends and between rubber and filler (especially using a ‘network visualisation’ technique). ‘Network visualisation’ involves swelling the vulcanisate to equilibrium with styrene, polymerising the styrene, sectioning the embedded, swollen vulcanisate, and staining with osmium tetroxide to reveal a rubber mesh structure, when observed by transmission electron microscopy (TEM). Measurement of this structure reveals a linear correlation between the mean mesh diameter and the molecular weight between crosslinks.
Network visualisation provides information about the interfaces between different rubbers and between rubber and fillers that cannot be readily obtained by any other technique. It also enables observation and measurement of localised crosslink densities and has been applied to the study of latex films.
For further information please contact Dr Andy Chapman.