Diamond Shamrock Corp.

Room temperature swelling experiments of sulfonyl fluoride fluoropolymers (Nafion) indicated that compounds having high relative volatility, F atoms, tertiary N groups, or cyclic ether O may be effective solvents for the polymers.Chlorotrifluoroethylene telomers barely swell the Nafions, but at high relative volatility they are completely dissolved.As the solution cools it becomes turbid at a temperature dependent upon both equivalent weight and solids content.Below this temperature the polymer forms a translucent gel and exudes a portion of the solvent.A number of F-containing solvents form relatively transparent gels with Nafions as they cool.

The optimum size exclusion chromatog. (SEC) method for poly(vinylpyrrolidone) (I) [9003-39-8] was based upon a stationary phase of diol-derivatized SiO₂ of pore sizes 3000, 500, and 75 Å and a mobile phase of 50:50 (volume/volume) MeOH [67-56-1]-water containing 0.1M LiNO₃.Sample recovery under identical conditions varied for the com. packings investigated and was inversely related to mol. weightThe latter phenomenon was rationalized on the basis of a limited number of active substrate sites available for binding.MeOH was a more effective mobile phase modifier than either DMF  [68-12-2] or MeCN [75-05-8], apparently because of its ability to function as a proton donor in H-bonding with I.Chromatog. evidence for the existence of a semipolyampholyte character in I is presented.A procedure for the construction of a column set log-linear in calibration and of extended dynamic range is described and is based upon hydrodynamic volume theory.

A series of 2-benzylsulfonylpyridine 1-oxides is described in which the identity of substituents on the pyridine ring, on the benzene ring, and in the α-benzyl position are varied.Preparation via several routes is described including the following: (1) condensation of a 2-halopyridine or a 2-halopyridine-1-oxide with a benzyl mercaptan followed by oxidation, (2) condensation of a 2-mercaptopyridine with a benzyl halide followed by oxidation, and (3) a novel 3-step onepot reaction involving metalation, sulfurization, and alkylation of a pyridine-1-oxide unsubstituted in the 2-position.A clear relationship is shown to exist between herbicidal activity and the identity of substituents on each part of the mol.Good turf growth retardation activity is also described for some compounds in this series.