Abstract: This invention relates to blends based on vinyl aromatic polymers endowed with high mechanical characteristics, even after successive processings at temperatures equal to or greater than 200.degree. C., comprising:a vinyl aromatic polymer containing from 0.5 to 5% by weight of a vinyl aromatic monomer-conjugated diene linear block polymer and from 5 to 15% by weight of a diene rubber;a polyolefine; anda vinyl aromatic monomer-conjugated diene linear block polymer, having a diene content between 20 and 80% by weight;the sum of the three components being equal to 100%.

Abstract: Process for the continuous bulk production of high impact vinylaromatic copolymers in which the vinylaromatic monomer, and if present, a comonomer selected from the group consisting of acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid and their alkyl- or cyclo-alkyl-esters containing from 1 to 8 carbon atoms in the alkyl group, the rubber, a part of the diluent solvent and the catalyst are premixed in a premixer at a temperature under 100.degree. C. and fed to a plug-flow agitated tubular reactor, which is divided into several stages or zones. The excess mixture is recycled to the premixer and the remaining part of the diluent solvent is injected into the top of the reactor to prevent the formation of incrustations. In the first zone of the reactor, the temperature and the residence time of the mixture are regulated so to have the halving the catalyst life.

Abstract: Exapandable beads of blends of poly (phenylene-ether) and a vinyl aromatic polymer are prepared by carrying out the polymerization of the vinyl aromatic monomer in presence of the poly(phenylene-ether) and of an expanding agent.

Abstract: A process for the devolatilization of polymer solutions including:(a) feeding the solution to a zone of indirect thermal exchange in which the ratio between the surface of thermal exchange and the flow per hour of the solution is over 80 m.sup.2 /m.sup.3 /h;(b) moving the solution forward into each channel at a speed below 0.5 mm/second;(c) keeping the solution of the polymer in each channel for about 120-200 seconds; and(d) separating the volatile components from the devolatilized polymer solution.

Abstract: Modified impact-resistant vinylaromatic copolymers containing from 2 to 10% by weight of an ethylenically unsaturated nutrile and from 0 to 30% by weight of alpha-methyl-styrene and having a gel content higher than 23%, a cracking resistance, in an olive oil/oleic acid mixture under a load of 10 MPa, higher than 100 min., and a melt index below 1.5 g/10 minutes.

Abstract: Process for the continuous production in solution of styrene thermoplastic resins by polymerization of a vinyl-aromatic monomer and of a vinyl-nitrile monomer in the presence of an elastomer and of a starter, wherein polymerization is conducted in two or more steps, wherein the elastomeric component is fed, in solution in the solvent and/or in the monomers, to the first step, polymerization is carried out in the subsequent steps at temperatures ranging from 70.degree. to 150.degree. C., in each step the reaction mass is gently and homogeneously stirred and the reaction product is caused to flow to a thin evaporator heated at 150.degree.-300.degree. C.