Abstract: Process for producing ethylidenorbornene (ENB) comprising a stage of thermal cracking of DCPD to CPD carried out in an inert fluid to which it is fed a stream of DCPD comprising virgin DCPD from cracking containing up to 10% wt of tetrahydroindene (THI) and recycled DCPD containing THI coming from the subsequent stage of formation of vinylnorbornene. The contact time of DCPD with the heat transfer fluid is of few seconds and it is sufficient to achieve a conversion of said DCPD ?95%, with little formation of oligomers. THI is then separated from the heat transfer fluid substantially free from DCPD and enriched in THI to a fractionation column.

Abstract: Process for the preparation of elastomeric copolymers of ethylene, wherein ethylene is copolymerized with an .alpha.-olefin, and possibly with a diene as termonomer, in the presence of a Ziegler-Natta catalyst including a solid component of catalyst based on titanium and aluminium, supported on magnesium chloride and obtained, in accordance with a special procedure, in the form of a spherical granular solid. This process produces elastomeric copolymers having a low crystallinity even with a high content of linked ethylene.

Abstract: Thermoplastic rubbers comprising propylene-ethylene copolymers containing from 50% to 90% by weight of propylene and showing, on X-rays examination in the unoriented state, crystallinity of the polypropylene and/or polyethylene type are disclosed.Also disclosed is a method for preparing the thermoplastic rubbers by polymerizing mixtures of propylene and ethylene in the presence of a catalyst obtained by mixing(A) a catalyst-forming component which is (a) an addition and/or substitution product of an electron-donor compound (or a Lewis base) with an Al-trialkyl compound, or (b) the addition reaction product of an electron-donor compound with an Al-alkyl compound containing two or more aluminum atoms bound to each other through an oxygen or nitrogen atom, component (A) being further characterized in that it is prepared by reacting 1.0 mole of an Al-alkyl compound with 0.1-1.

Abstract: Thermoplastic rubbers comprising propylene-ethylene copolymers containing from 50% to 90% by weight of propylene and showing, on X-rays examination in the unoriented state, crystallinity of the polypropylene and/or polyethylene type are disclosed.Also disclosed is a method for preparing the thermoplastic rubbers by polymerizing mixtures of propylene and ethylene in the presence of a catalyst obtained by reacting.(A) a catalyst-forming component which is (a) an addition and/or substitution product of an electron-donor compound (or a Lewis base) with an Al-trialkyl compound, or (b) the addition reaction product of an electron-donor compound with an Al-alkyl compound containing two or more aluminum atoms bound to each other through an oxygen or nitrogen atom, component (A) being further characterized in that it is prepared by reacting 1.0 mole of a Al-alkyl compound with 0.1-1.