Abstract: There is provided a mold fabricated from thermoplastic material incorporatinog a thin flexible, substantially knife-edged rim projecting from the periphery of the mold cavity on both the male and female portions thereof, and having a reservoir to contain additional monomer, such reservoir being separated from the mold cavity by the conjunction or mating line of the peripheral rim projections.Such molds are useful for the molding of optical implants which do not require further machining or similar treatment.

Abstract: There is provided a mold comprising a male and a female mold member fabricated from thermoplastic polymeric materials which, in very thin sections are flexible under polymerization conditions, but, under said conditions are sufficiently inflexible in thick sections to retain their shape and surface characteristics. Said mold is provided, on either the male or the female member with a thin rim which, during the polymerization process, flexes and permits the mold members to approach each other and compensate for the shrinkage that occurs during polymerization. Said thin rim further forms the edge of the finished lens.

Abstract: There is provided a mold comprising a male and a female mold member fabricated from thermoplastic polymeric materials which, in very thin sections are flexible under polymerization conditions, but, under said conditions are sufficiently inflexible in thick sections to retain their shape and surface characteristics. Said mold is provided, on either the male or the female member with a thin rim which, during the polymerization process, flexes and permits the old members to approach each other and compensate for the shrinkage that occurs during polymerization. Said thin rim further forms the edge of the finished lens.

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.