Title

Aqueous Cationic Polymerization of P-Methoxystyrene Using Hydrophilic Phenylphosphonic Acids

Document Type

Article

Publication Date

2004

Department

Polymers and High Performance Materials

Abstract

The use of phosphonic acids [(HO)(2)P(O)R, R = Ph or Ph-o,m,p-NO2] in conjunction with a water-tolerant Lewis acid, ytterbium trifluoromethanesulfonate [Yb(OTf)(3)], induces the cationic polymerization of p-methoxystyrene (pMOS). The polymerization is performed by addition of pMOS to a suspension of either nitrophenylphosphonic acid (NO(2)PPA) or phenylphosphonic acid (PPA) in an aqueous solution of Yb(OTf)(3) at 23degreesC. Higher [NO(2)PPA](0) yielded higher initial polymerization rates, but had no effect on ultimate monomer conversion. Compared to PPA, NO(2)PPA yielded higher polymerization rates and higher ultimate conversions; however, PPA resulted in more controlled molecular weights and lower molecular weight distribution (MWD). The number-average molecular weights of the polymers increased with conversion while MWD decreased. The polymerization rate was affected by the presence of polar or non-polar solvents. Increasing the polymerization temperature dramatically increased the polymerization rate.

Publication Title

Journal of Macromolecular Science: Pure and Applied Chemistry

Volume

A41

Issue

3

First Page

257

Last Page

266