Abstract: Process for the preparation of polyalkenyl acylating agents which comprises: a. reacting at a temperature higher than 180° C. a reactive polyalkene, having a number average molecular weight Mn ranging from 500 to 5000 and having a content of terminal vinylidene groups greater than or equal to 30%, with an enophile; b. thermally carrying out the reaction for a time sufficient for having a conversion of the terminal vinylidene groups higher than 15%; c. completing the reaction always under heat in the presence of a reaction accelerator consisting of a Lewis acid selected from a tin, zinc, aluminum or titanium halide.

Abstract: Electrochemical devices allowing high performances in resistance, thermal stability and conductivity comprising polymeric ionic exchange membranes and ionomers are described.

Abstract: A thermoplastic elastomeric material includes a vulcanized rubber in a subdivided form surface-grafted with at least one vinyl polymer, wherein the amount of the surface-grafted vinyl polymer is not lower than 60% by weight, preferably not lower than 70% by weight, more preferably not lower than 80% by weight, with respect to the total weight of the surface-grafted vinyl polymer and the vulcanized rubber in a subdivided form.

Abstract: A process for manufacturing a thermoplastic elastomeric material includes at least one elastomeric phase and at least one thermoplastic phase by the following steps: surface-treating a vulcanized rubber in a subdivided form with an effective amount of at least one organometallic polymerization catalyst; and polymerizing at least one ethylenically unsaturated monomer in the presence of the surface-treated vulcanized rubber in a subdivided form to obtain at least one thermoplastic phase.

Abstract: The present invention relates to a controlled radical grafting process of a polyolefin derived from monomeric units including ?-olefins. This process comprises the reaction of the polyolefin and at least one radical reaction initiator with a grafting system which comprises at least one grafting compound having an electron donator heterocyclic aromatic ring conjugated to at least one —HC?CR1R2 group in which at least one of R1 and R2 is an electron acceptor functional group. The process can be performed continuously in an extruder or discontinuously in a mechanical mixer.

Abstract: A process for manufacturing a thermoplastic elastomeric material includes the following steps: surface treating a vulcanized rubber in a subdivided form in order to provide radically transferable atoms or groups on its surface; grafting at least one vinyl monomer to the surface treated vulcanized rubber in the presence of at least one transition metal compound and at least one ligand so as to obtain a vinyl polymer grafted onto the surface of the vulcanized rubber in a subdivided form.

Abstract: Process for the preparation of polyalkenyl acylating agents which comprises: a. reacting at a temperature higher than 180° C. a reactive polyalkene, having a number average molecular weight Mn ranging from 500 to 5000 and having a content of terminal vinylidene groups greater than or equal to 30%, with an enophile; b. thermally carrying out the reaction for a time sufficient for having a conversion of the terminal vinylidene groups higher than 15%; c. completing the reaction always under heat in the presence of a reaction accelerator consisting of a Lewis acid selected from a tin, zinc, aluminum or titanium halide.

Abstract: The present invention relates to a controlled radical grafting process of a polyolefin derived from monomeric units including ?-olefins. This process comprises the reaction of the polyolefin and at least one radical reaction initiator with a grafting system which comprises at least one grafting compound having an electron donator heterocyclic aromatic ring conjugated to at least one —HC?CR1R2 group in which at least one of R1 and R2 is an electron acceptor functional group. The process can be performed continuously in an extruder or discontinuously in a mechanical mixer.

Abstract: Described herein are polyolefins functionalized with maleic anhydrid and at least one high-boiling ester of the latter, and a process for their preparation in high yields, with high degrees of functionalization, without the production of by-products of cross-linking or degradation. The process, which may be carried out either continuously or discontinuously, is characterized by the use of inorganic substances having a specific porosity, grain size, density and humidity, as vehicles of the functionalizing monomers; the presence of maleic ester contributes to enhancing the reaction efficiency. Likewise described herein is a double-screw extruder devised for carrying out the said process, and the use of products obtained as compatibilizing additives in the field of adhesive and reinforcing polymers.

Abstract: A catalyst for the polymerization of vinylaromatic monomers, and particularly styrene, with a high yield and a high syndiotacticity index, comprises the product consisting of the following two components in contact with each other: A) an &eegr;5-cyclopentadienyl complex of titanium; B) an organo-oxygenated compound of aluminum; and contains a sufficient amount of at least one carboxylated product having the following general formula: R—COO—G  (I) wherein R—COO is a carboxylic group comprising the organic radical R having from 1 to 30 carbon atoms, and G represents a hydrogen atom, an aliphatic or aromatic hydrocarbon group having from 1 to 20 carbon atoms or a metal atom, possibly substituted, linked to said carboxylic group.

Abstract: Ethylene homopolymers and ethylene copolymers with alpha-(C.sub.3 -C.sub.10)-olefins are obtained by polymerizing the monomers with a polymerization catalyst formed by:a) an alkyl-aluminum; andb) a modified solid catalyst component obtained by treating with a Lewis' base a non-modified solid component to be defined by means of the following formula, expressed as atomic proportions:Ti(1), hf(0.5-3), Si (1-6), Mg (0.5-15) Al (0.5-15),X (20-60, ROH (1-10)wherein:X represents either chlorine and bromine, andR represents either a linear or branched alkyl radical of from 1 to 6 carbon atoms.The catalyst is particularly useful for controlling the molecular weight and the molecular weight distribution of ethylene hompolymers and copolymers.