Examples of such materials are acrylates and especially methacrylates such as methyl acrylates, butyl methacrylates, methyl methacrylate, methyl methacrylate copolymers with other acrylates, ethyl methacrylates, isobutyl methacrylates, vinyl acetate/vinyl chloride copolymers of low molecular weight, and aliphatic polyesters.