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: Process for preparing shaped bodies with integrated polyurethane skin, which process comprises:(a) charging to a closed mould for rotational moulding a first premixed reactive polyurethane system;(b) causing the mould to rotate, according to rotational moulding technology, for a long enough time to form a thin layer of partially polymerised material on the inner surface of said mould; and(c) discontinuing the rotation and charging to the mould a reactive material which will fill the inner mould hollow.

Abstract: A procedure is described for the preparation of a vanadium bis-arene, [V(arene).sub.2 ], starting from vanadium oxychloride, aluminium metal, aluminium trichloride and an arene, wherein:(a) vanadium oxychloride (VOCl.sub.3), active aluminium metal, and aluminium trichloride are put in contact with each other, in a liquid arene, to transform the vanadium oxychloride into the complex compound [V(arene).sub.2 ].sup.+ [AlCl.sub.4 ].sup.- ;(b) a liquid cyclic or acyclic or acyclic ether is added to the reaction product of step (a) to reduce [V(arene).sub.2 ].sup.+ to [V(arene).sub.2 ]; and(c) the vanadium bis-arene [V(arene).sub.2 ] is recovered from the reacton product of step (b).The vanadium bis-arenes thus obtained are use in the preparation of catalysts for the polymerization of olefins.

Abstract: Thoughened thermoplastic compositions are described having a good balance of mechanical, thermal and process properties, comprising:at least a polyphenylene ether,at least a polyamide,an elastomeric copolymer containing a vinyl aromatic polymer grafted on an olefinic elastomer, andan organic diisocyanate.

Abstract: Polymeric compositions characterized by their excellent thermal stability containing a polyphenylene ether or one of its blends with at least one (co)polymer of styrene and at least one compound belonging to the group of linear and/or cyclic beta diketones.Beta-diketones are capable of giving polyphenylene ether and/or its blends with styrenic polymers a long-lasting thermal stability in the molten state and of guaranteeing sufficient fluidity to ensure better processability compared to the same polymers in the known art.

Abstract: Polymeric compositions based on at least one polyphenylene ether, obtained from the (co)polymerization by oxidative coupling of one or more substituted phenols, either alone and/or together with at least one (co)polymer of styrene, are thermically stabilized by adding at least one compound having the structural formulaR--C.tbd.C--COOH (I)where R has the meaning described in the text. These compositions are characterized by the fact that they have excellent thermal stability in the molten state, are long-lasting and have a much better fluidity and processability compared to the corresponding polymeric blends which do not contain (I).

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.