Sulfonated polymers

A shaped polymer, to which hydrophilic character has been imparted by the method comprising:

• contacting the shaped polymer with a gaseous mixture consisting essentially of sulfur dioxide and a source of oxygen, in which the mixture has a mole ratio of sulfur dioxide to the source of oxygen which is equal to or greater than a stoichiometric ratio;
• and
• continuously exposing the shaped polymer and gaseous mixture to ultraviolet light while the shaped article is in contact with the gaseous mixture;
• wherein contacting and exposing are carried out at a pressure of less than 1 atmosphere;
• wherein said polymer is selected from the group consisting of alkyd resins, allylic resins, amino resins, epoxy resins, phenolic resins, polyesters, silicones, urethanes, polyacetals, acrylic and methacrylic polymers, polyamides, parylenes, polyaryl sulfones, polyesters, polyaryl sulfides, polyimides, polyethylene, polypropylene, poly(1-butene), poly(2-butene), poly(1-pentene), poly(2-pentene), poly(3-methyl-1-pentene), poly(4-methyl-1-pentene), 1,2-poly-1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene, polyacrylonitrile, poly(vinyl acetate), polystyrene, and copolymers thereof.

A sulfonated polymer that has not been discolored, said sulfonated polymer prepared by the method comprising:

• continuously exposing a gaseous mixture consisting essentially-of sulfur dioxide and a source of oxygen to ultraviolet light, in which the mixture has a mole ratio of sulfur dioxide to the source of oxygen which is equal to or greater than a stoichiometric ratio;
• and
• contacting the polymer with the exposed gaseous mixture;
• wherein exposing and contacting are carried out at a pressure of less than 1 atmosphere and continuous exposure is carried out for as long as the exposed gaseous mixture is in contact with the polymer;
• wherein said polymer is selected from the group consisting of alkyd resins, allylic resins, amino resins, epoxy resins, phenolic resins, polyesters, silicones, urethanes, polyacetals, acrylic and methacrylic polymers, polyamides, parylenes, polyaryl sulfones, polyesters, polyaryl sulfides, polyimides, polyethylene, polypropylene, poly(1-butene), poly(2-butene), poly(1-pentene), poly(2-pentene), poly(3-methyl-1-pentene), poly(4-methyl-1-pentene), 1,2-poly-1,3-butadiene, 1,4-poly-1,3-butadiene, polyisoprene, polyacrylonitrile, poly(vinyl acetate), polystyrene, and copolymers thereof.