Thermosetting poly(thio)urethane formulation comprising at least one block copolymer and use thereof in optics for the production of organic lenses having improved toughness

A liquid polymerizable mixture comprising:

• a thermosetting polymerizable composition, which is the precursor, by polymerization, of a first thermoset polymer material, wherein the thermosetting polymerizable composition comprises at least one polythiol and/or at least one polyol, and at least one polyiso(thio)cyanate;
• and
• a second polymer material solubilized in said thermosetting polymerizable composition, wherein:
• the second material comprises at least one block copolymer comprising at least two polymer blocks, A and B, said block A being an elastomer block and said block B being able to absorb an amount of water of at least 2% of its weight, wherein:
• the block A is a block homopolymer or copolymer comprising at least one monomer unit further defined as 2-methoxyethyl acrylate, butyl acrylate, methyl acrylate, benzyl acrylate, or 2-phenoxyethyl acrylate, and
• the block B is a poly(N,N-dimethyl acrylamide) block homopolymer, poly(N-vinylpyrrolidin-2-one) block homopolymer, poly(ethylene oxide) block homopolymer, block copolymer comprising a N,N-dimethyl acrylamide monomer unit, block copolymer comprising a N-vinylpyrrolidin-2-one monomer unit, block copolymer comprising an ethylene oxide monomer unit, or block copolymer comprising a mixture of at least two of N,N-dimethyl acrylamide, N-vinylpyrrolidin-2-one, or ethylene oxide monomer units;
• the second material forms, after polymerization at a temperature ranging from 80 to 140° C. of the polymerizable mixture, elastomer block A-rich areas dispersed within the first material, wherein the largest area size is less than 80 nanometers;
• and
• the second material represents from 5 to 50% by weight of the polymerizable mixture.