Abstract: The invention concerns a method for preparing stable (co)polymer dispersions in a polyol by polymerising in situ a monomer or a mixture of ethylenically unsaturated monomers, in the presence of one or several azocarboxylic acid ester(s).

Abstract: This composition, which is useful as a binder in the preparation of synthetic resin concretes or mortars, bonding primers or finishing coats, comprises (A) a system of monomers comprising: (a1) 50-90 parts of a dicyclopentenyloxyalkyl eater: where R=H or CH3; n=1 or 2; and R1=C2-C6 alkylene; (a2) 0-25 parts of at least one heavy (meth)acrylate giving a homopolymer with a Tg higher than that of a homopolymer of (a1); (a3) 0-25 parts of at least one heavy (meth)acrylate giving a homopolymer with a Tg lower than that of a homopolymer of (a1); (a4) 0-25 parts of at least one monomer containing at least two (meth)acrylic unsaturations; and (B) 5-30 parts of at least one poly(allyl glycidyl ether); and (C) an initiating system chosen from (C1) to (C4): (C1) 0.1-3 parts of at least one organic peroxide derived from a C3-C18 hydrocarbon compound and 0.1-2 parts of at least one aromatic amine; (C2) 0.