Handbook of Solvents - George Wypych - ChemTech - Ventech!

818 Maw-Ling Wang
(F) Polymerization by PTC
Poly(ethylene glycol)-block-poly(butylacrylate), synthesized by radical polymerization,
56 were obtained by PTC in the Williamson reaction. The morphology and the
crystallinity of the cast film of the block polymer were significantly affected by the organic
solvent.
The technique of phase-transfer catalysis has been extensively applied to the
two-phase polycondensation using various phase-transfer catalysts, such as quaternary ammonium
and phosphonium salts, crown ethers and poly(ethylene glycol)s. 8,11,30,46,53,75,87,119,151
Various types of condensation polymers such as aromatic polysulfonates and polysulfides,
aromatic polyethers, aliphatic and aromatic polysulfides, and carbon-carbon chain polymers
of high molecular weights by the phase-transfer catalyzed polycondensation from
combinations of aromatic disulfonyl chlorides, phosphonic dichlorides, activated aromatic
dichlorides, and aliphatic dihalides, with bisphenol, aliphatic and aromatic dithiols, and active
ethylene compounds. The two-phase polycondensation was generally carried out in a
water-immiscible organic solvent-aqueous alkaline solution system at room temperature.
The method of polycondensation offers a highly versatile and convenient synthetic method
for a variety of condensation polymers.
Aromatic polysulfonates of high molecular weights can be prepared from aromatic
disulfonyl chlorides and alkaline salts of bisphenols by interfacial polycondensation technique
using onium salt accelerators. In the absence of the catalyst, only low molecular
polysulfonate III was obtained, even though the reaction was continued for 254 hours,
whereas the addition of these quaternary ammonium salts and crown ethers increased the
average molecular weight of the polymer remarkably.
[13.3.11]
Among the catalysts, TBAC and DC-18-C-6 were found to be highly efficient, leading
to the formation of the polysulfonate with an inherent viscosity [η] of as high as 1.4 dLg -1 .
Similarly, aromatic polysulfonates and aromatic polyether were synthesized from the
polycondensation of phenylphosphonic dichloride (IV) with bisphenol A (II) leading to a
polyphosphonate (V), aromatic dihalides (VI) with alkaline salts of bisphenols (VII), under
various phase transfer catalysis in two-phase system, i.e.,
[13.3.12]