VULCANIZATION OF LIQUID POLYBUTADIENE (III)

Liquid chromatography/mass spectrometry identification of intermediates and vulcanization products by using squalene as vulcanization model compound.

RATIONALE Sulfur-vulcanized rubber is a three-dimensional polymer network, insoluble in all organic solvents. For this reason, vulcanization products are difficult to study and identify by conventional analytical techniques. To simplify this task, low molecular weight olefins have been used as model compounds (MCs) in place of rubber in vulcanization experiments. METHODS In this work, the vul...

Theory & Practice Of Vulcanization

High temperature liquid chromatography of triazole fungicides on polybutadiene-coated zirconia stationary phase.

High temperature liquid chromatography using water-rich and superheated water eluent is evaluated as a new approach for the separation of selected triazole fungicides, hexaconazole, tebuconazole, propiconazole, and difenoconazole. Using a polybutadiene-coated zirconia column at temperatures of 100-150 degrees C, clear separations were achieved when 100% purified water was utilized as organic-fr...

Critical behaviour for vulcanization processes

2014 We consider a polymer melt, with polymerization index N and a fraction p of cross linked monomers, for values of p close to the gelation threshold (p = 03C1c + 039403C1). Using a Ginsburg argument, we find that (in three dimensions) the Flory theory is qualitatively correct whenever N > (03C1c/039403C1)3. For shorter chains the critical exponents are expected to be of the percolation ...

Density-correlator signatures of the vulcanization transition

Certain density correlators, measurable via various experimental techniques, are studied in the context of the vulcanization transition. It is shown that these correlators contain essential information about both the vulcanization transition and the emergent amorphous solid state. Contact is made with various physical ingredients that have featured in experimental studies of amorphous colloidal...