Abstract: Reinforced polyolefinic thermoplastic composition comprising a polyolefin, an aluminum and/or magnesium silicate and a maleamic silane.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part including titanium, magnesium, chlorine and alkoxylic groups and is obtained: by suspending an activated silica in a solution of magnesium chloride and titanium tetraalcoholate in a liquid aliphatic acid ester; eliminating the aliphatic acid ester from the resulting suspension to recover a solid; and making this solid react with an aluminium alkyl chloride. It is preferable to add also some measured quantities of a silicon halide to the solution in aliphatic acid ester.

Abstract: A supported solid component of catalyst, for the stereospecific polymerization of propylene and other .alpha.-olefins, is obtained by making a non-activated silica interact in succession with: (i) a magnesium dialkyl or halide of magnesium alkyl; (ii) a halogenating agent selected from silicon, tin and antimony halides; (iii) a titanium tetrahalide; and (iv) a Lewis base. A catalyst for the stereospecific polymerization of propylene and other .alpha.-olefins is composed of: (A) the solid component of catalyst; (B) an aluminium trialkyl or aluminium alkyl halide; and (C) an electron donor compound, capable of forming a complex compound with component (B).

Abstract: Process for producing foamable particles of styrenic polymers, which consists in submitting said particles to a partial loss of foaming agent, performed in an oven at a lower temperature than the glass transition temperature (Tg) of said particles.

Abstract: Thermoplastic compositions having improved mechanical characteristics and particularly an improved impact resistance, especially when measured on test pieces having high thickness, comprising:(A) an impact resistant vinyl aromatic graft copolymer containing an amount comprised between 0.1 and 2% by weight of an ethylenically unsaturated compound having a carboxylic group or one of its derivatives in the molecule; and(B) a polyamide resin.

Abstract: Thermoplastic compositions with improved mechanical characteristics, including:a) a graft impact-resistant vinylaromatic copolymer containing a quantity of between 0.1 and 2% by weight of an ethylenically unsaturated compound having a carboxylic group or one of its derivatives in the molecule;b) a polyamide resin andc) a polyolefin.

Abstract: A thermoplastic composition based on a polyolefin and a vinyl aromatic polymer, having an improved combination of physical, mechanical and thermal properties, comprising:from 40 to 80% by weight of a vinyl aromatic polymer (A) containing, as an elastomeric component, from 0.5 to 5% by weight of a vinyl aromatic monomer - conjugated diene linear block polymer and from 5 to 15% of a diene rubber, from 5 to 50% by weight of a polyolefin (B) and from 10 to 50% by weight of an olefinic elastomer (C) containing, grafted thereon, a vinyl aromatic polymer, wherein the molar ratio between the vinyl aromatic polymer and the olefinic elastomer in the grafted phrase is greater than 0.8, the sum of components (A), (B) and (C) being equal to 100%.

Abstract: A supported Ziegler-Natta catalyst active in ethylene polymerization and in the copolymerization of ethylene with alpha-olefins consists of:(A) a cocatalyst in the form of an organometallic compound of aluminium, and(B) a solid catalyst component obtained by:(i) impregnating a granular solid support with a solution of a titanium alcoholate and magnesium chloride in a liquid aliphatic hydrocarbon, followed by evaporation of the hydrocarbon solvent;(ii) impregnating the support treated in (i) with a solution of magnesium chloride in a liquid aliphatic ester, followed by evaporation of the ester solvent; and(iii) activating the support treated in (ii) by contact with an alkyl aluminium halide.In a preferred embodiment, measured quantities of a silicon halide are introduced in stage (i) and/or (ii), this considerably improving catalytic activity.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene, including magnesium, halogen and titanium, is prepared:(i) by dissolving a magnesium dialkyl, a silicon halide and at times also an alkyl halide, in an inert organic solvent and maintaining contact until a granular solid precipitates;(ii) putting this granular solid in contact and making it react with a titanium halide, alkoxide or halogen-alkoxide, to produce a solid component of catalyst; and(iii) activating this solid component of catalyst by contact with aluminium alkyl halide, if a titanium alkoxide or halogen-alkoxide has been used in phase (ii).

Abstract: Flame-retardant thermoplastic composition including a styrene polymer containing thoroughly incorporated therein an effective quantity of a synergetic mixture composed of a chlorinated hydrocarbon compound containing at least 40% by weight of combined chlorine, an inorganic compound containing oxygen of a metal belonging to group III or IV of the periodic table, and polytetrafluoroethylene having a particle size which is less than 20 microns.

Abstract: Thermoplastic compositions having improved mechanical, thermal and rheological characteristics comprising a blend of:(A) an impact resistant vinyl aromatic copolymer containing a vinyl aromatic monomer, an ethylenically unsaturated nitrile and a substrate of an olefinic elastomer;(B) a polyamidic resin;(C) a compatibilizing polymer containing from 0.01 to 4% mol. of a functional group reactive with the polyamide resin and(D) a polyolefin.

Abstract: A process for preparing aromatic polyesters having excellent physico-mechanical and solvent-resistance properties, consisting in reacting at least a dialkyl ester of an aromatic diacid with an aromatic polycarbonate and/or an aromatic dialkyldicarbonate in the presence of an esterification or transesterification catalyst.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part which includes titanium, magnesium, chlorine and also alkoxy groups, and is obtained: by suspending an activated silica in an ethanolic solution of magnesium chloride; by contact of the suspension with an alkoxy or halogen alkoxyde of titanium and with a silicon halide; by eliminating the ethanol from the resulting suspension in order to recover a solid matter; and by making this solid react with an aluminium alkyl chloride.

Abstract: A solid component of a catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part which includes titanium, magnesium, chlorine and also alkoxy groups, and is obtained: by suspending an activated silica in an ethanolic solution of magnesium chloride; by contact of the suspension with an alkoxy or halogen alkoxyde of titanium and with a silicon halide; by eliminating the ethanol from the resulting suspension in order to recover a solid matter; and by making this solid react with an aluminum alkyl chloride.

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: Rapidly-crystallizing polyester compositions comprising a polyester thermoplastic resin and a styrene polymer having an essentially syndiotactic structure.

Abstract: Compositions comprising from 5 to 50% by weight of a polyphenylene ether and from 95 to 50% by weight of a styrene polymer having a syndiotactic structure. Such compositions are endowed with enhanced mechanical properties compared to those containing amorphous polystyrene, or polystyrene having an isotactic structure.

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.