| abstract |
Polymerizable compositions are described comprising: (a) a mixture of thio(meth)acrylate functional monomers comprising: (a)(i) a first thio(meth)acrylate functional monomer, e.g., bis(thiomethacrylate)-1,2-ethylene; and (a)(ii) a second thio(meth)acrylate functional monomer, which is chain extended; (b) an aromatic monomer having at least two vinyl groups, e.g., divinyl benzene; (c) a polythiol monomer having at least two thiol groups, e.g., pentaerythritol tetrakis(3-mercaptopropionate); and (d) a comonomer selected from: (d)(i) an anhydride monomer having at least one ethylenically unsaturated group, e.g., methacrylic anhydride; (d)(ii) a monomer having at least three (meth)acryloyl groups, e.g., pentaerythritol tetrakis(acrylate); and (d)(iii) mixtures of monomers (d)(i) and (d)(ii). A polymerizate of the polymerizable composition has a refractive index of at least 1.57 and an Abbe number of at least 33. |