Abstract: High impact strength cast sheet materials having an unnotched Charpy impact strength of at least 60 kJ/m.sup.2 comprise an interpenetrating network of a major amount of a reticulated methyl methacrylate polymer and from 3% to 8% by weight of an elastomeric polyurethane.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

Abstract: A component system for surgical cement, based on at least one acrylic monomer and at least one acrylic polymer comprising a powder and a liquid. The powder comprises: (a) from 50 to 70 weight percent of at least one acrylic polymer having a particle size of between 20 and 150 microns; and (b) a polymerization initiator. The liquid comprises: (a) from 30 to 50 weight percent of a mixture comprising at least 65 weight percent of at least one acrylic monomer and up to 35 weight percent of at least one acrylic polymer; (b) at least one polymerization activator; and (c) from 0.05 to 1 weight percent, relative to the total amount of acrylic monomer, of at least one chain stopper chosen from the group consisting of diunsaturated monocyclic terpenes and monounsaturated bicyclic terpenes. Application to the manufacture of surgical cements.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.