Abstract: Polyurethane polymers characterized by a molecular weight above 6,000 and having lactone groups and hydroxyl groups in the polymer backbone are prepared by reacting a mixture of polyglycols proportioned so as to provide the desired polymer properties, a polyfunctional lactone and a polyfunctional isocyanate. The product is soluble in alkaline solutions and may be used for light sensitive photographic layers on films, paper or glass; in drug delivery systems, as burn dressings, in body implants such as vascular prosthesis, and in the manufacture of catheters. The novel polymers also find use in the manufacture of artificial finger nails, finger cots, adhesives, and in protective and hydrostatic drag resistant coatings. The water absorptivity of the polyurethane lactone polymers is above 10%, preferably above 20%, and these polymers may range to completely gel-like high water absorptive polymers.

Abstract: Hydrophilic polymers, i.e., hydrophilic cellulose esters, hydrophilic cellulose ethers, hydrophilic polyurethanes, hydrophilic vinyl lower alkyl ether polymers, vinyl alcohol group containing polymers, partially hydrolized polyacrylonitrite, ethylene-maleic anhydride copolymer, stryene-maleic anhydride copolymer, proteins, high molecular weight polyalkylene oxides or phenoxy resins, having encapsulated therein either or both anti-fouling agents or pigments is applied as a coating to underwater portions of a marine structure so as to reduce the drag of said structure.

Abstract: A process for preparing hydrophilic cross-linked polymers and products prepared thereby, said process comprising admixing in a solvent-free system in the presence of a free radical, vinyl polymerization catalyst and reacting a major amount of a water-soluble polymerizable monoester of an olefinic acid having at least one substituted functional group with a minor amount of a polymerizable diester of one of said olefinic acids having at least two esterifiable hydroxyl groups. The novel products include a solid friable foam which can be disintegrated to powder. Shaped bodies can be prepared in the form of articles which can be cast with additives such as fragrances, medicinals, flavors, chemicals and the like, which are gradually released from the article when it is wetted in water or alcohol. Liquid casting syrups adapted to be polymerized in situ with or without additives can be formed.