Not only failed to inhibit the radical poly-merization but also induced the formation of carbenium ion in the EB dispersion, which resulted in the increase of branched degree and trans-vinilenovoy (--CH=CH--).
Differ with conventional cationic initiating system (e.g., [H.sub.2]O/Lewis acid, halogen alkyl/Lewis acid) 110, 111, [A1Cl.sub.3] mainly interact with PE molecular fragments produced by the dispersion of ER to target and then produce carbenium ions (12).
This addition of monomer results in monomer being in between carbenium ion and its negative gegenion.
The propagation step involves H: shift and :CH3 group shift to form tertiary carbenium ion which is more stable and abundantly available during propagation.
The former is a vinyl polymerization and proceeds through carbenium ion
formation while the latter is ring opening generating an active species known as an onium ion.
One very early application of the superacid 100% [H.sub.2.SO.4] was the preparation of stable solutions of aryl carbenium ions
such as the triphenyl carbenium ion
[(C.sub.6.H.sub.5).sub.3.C.sup.+] from the corresponding alcohol.
Akzo has established, from quantum chemical calculations, a rule for judging the charge distribution on carbenium ions
- products of the metabolism of nitrosamines (figure 5).
Ron Childs, FCIC, has an international reputation for his studies of homoaromaticity and thermal and photochemical pericyclic reactions of carbenium ions
. His most recent efforts have been directed towards solid-state NMR and x-ray crystallographic studies of isolable carbocations, the thermal and photochemistry of iminium salts related to the visual pigments, and the use of photochemical methods for the fabrication of charge-mosaic piezodialysis membranes.