Syrup (meth) acrylic liquid, method of impregnating a fibrous substrate with said syrup, and composite material obtained after polymerization of said syrup impregnation

The invention relates to a syrup (meth) acrylic viscous liquid comprising: a) a (meth) acrylic acid, b) a (meth) acrylic acid, c) an initiator to start the polymerization of (meth) acrylic acid, said initiator being in the form of a liquid peroxide compound in a temperature range between 0 ° and 50 ° C, said syrup being characterized in that the initiator is combined with an accelerator system comprising: d) a reducing compound, e ) a metal salt or mixture of metal salts not comprising Cobalt and f) a tertiary amine.