Abstract: Composition based on a crosslinkable polyethylene comprising from 0.05 to 0.24 hydrolysable silane groups per 100 —CH2— units and having a standard density SD of at least 954 kg/m3 and a melt flow index MI5 of less than 1.5 g/10 min. Pipes for the transportation of fluids under pressure, which can be obtained by extruding this composition and then hydrolysing it.

Abstract: Multi-layered pipe comprising a main layer of polyethylene compound having a resistance to stress cracking NPT measured according to ISO 13479 standard of less than 8000 hours and an internal layer of polyethylene compound having a resistance to stress cracking NPT of higher than 8000 hours, the thickness of the internal layer being between 1 and 25% of the total pipe thickness but not less than 0.3 mm.

Abstract: Composition based on a crosslinkable polyethylene comprising from 0.05 to 0.24 hydrolysable silane groups per 100 —CH2— units and having a standard density SD of at least 954 kg/m3 and a melt flow index MI5 of less than 1.5 g/10 min. Pipes for the transportation of fluids under pressure, which can be obtained by extruding this composition and then hydrolysing it.

Abstract: Polyphenylene sulphide-based compositions essentially containing 60 to 99.5% by weight of polyphenylene sulphide and 0.5 to 40% by weight of a combination (C) containing a compound (C1) chosen from olefinic elastomers containing epoxy groups and a compound (C2) chosen from crosslinking agents containing functional groups which are reactive towards the epoxy groups of the compound (C1) and are chosen from amino, hydroxyl, carboxyl and carboxylic acid anhydride groups. They are obtained by melt-blending polyphenylene sulphide with each of the compounds (C1) and (C2) of the combination (C) successively and in any order.

Abstract: Compositions comprising one or more olefin polymers functionalized by at least one functionalization agent chosen from carboxylic acids, their esters, their anhydrides and their metal salts and one or more stabilizing agents comprising one or more sterically hindered phenol groups and at most one ester functional group. Process for their preparation and use of these compositions for compatibilizing olefin polymers with polymers, fillers and metal substrates which are incompatible with olefin polymers.

Abstract: Multi-layered pipe comprising a main layer of polyethylene compound having a resistance to stress cracking NPT measured according to ISO 13479 standard of less than 8000 hours and an internal layer of polyethylene compound having a resistance to stress cracking NPT of higher than 8000 hours, the thickness of the internal layer being between 1 and 25% of the total pipe thickness but not less than 0.3 mm.

Abstract: Polyphenylene sulphide-based compositions essentially containing 60 to 99.5% by weight of polyphenylene sulphide and 0.5 to 40% by weight of a combination (C) containing a compound (C1) chosen from olefinic elastomers containing epoxy groups and a compound (C2) chosen from crosslinking agents containing functional groups which are reactive towards the epoxy groups of the compound (C1) and are chosen from amino, hydroxyl, carboxyl and carboxylic acid anhydride groups. They are obtained by melt-blending polyphenylene sulphide with each of the compounds (C1) and (C2) of the combination (C) successively and in any order.

Abstract: Polyphenylene sulphide-based compositions with improved impact strength and process for preparing them Polyphenylene sulphide-based compositions essentially containing 60 to 99.5% by weight of polyphenylene sulphide and 0.5 to 40% by weight of a combination (C) containing a compound (C1) chosen from olefinic elastomers containing epoxy groups and a compound (C2) chosen from crosslinking agents containing functional groups which are reactive towards the epoxy groups of the compound (C1) and are chosen from amino, hydroxyl, carboxyl and carboxylic acid anhydride groups. They are obtained by melt-blending polyphenylene sulphide with each of the compounds (C1) and (C2) of the combination (C) successively and in any order.

Abstract: Containers or linings formed from thermoplastic polymeric materials are provided which are suitable for use in transport and storage of aqueous oxidizing agents and the thermoplastic polymeric materials themselves. The thermoplastic polymeric materials such as polyethylene, forming the container or linings are stabilized against embrittlement caused by interaction with peracid solutions they contact by the incorporation of a thioether and preferably a hindered phenol anti-oxidant. The thioether particularly comprises additionally a hindered phenol and is, for example, a thiobisphenol. The stored peracid solutions exhibited improved storage stability. The containers or linings are particularly suitable for storing or transporting aqueous peracid solutions in locations enjoying relatively high ambient temperatures.

Abstract: Continous process for grafting a polyolefin within a melt including a polyolefin of linear olefin containing from 2 to 8 carbon atoms, a graftable functional monomer and a radical-generator, in an extruder including at its exit a compression zone followed by a discharge zone, in which at least one antioxidant additive is introduced into the melt not later than before the latter enters the compression zone of the extruder.Stabilized grafted polyolefin obtained by means of this process.

Abstract: Continuous process for grafting a polyolefin within a melt including a polyolefin of linear olefin containing from 2 to 8 carbon atoms, a graftable functional monomer and a radical-generator, in an extruder including at its exit a compression zone followed by a discharge zone, in which at least one antioxidant additive is introduced into the melt not later than before the latter enters the compression zone of the extruder.Stabilized grafted polyolefin obtained by means of this process.

Abstract: Propylene polymer containing monomer units derived from at least one functional compound (A) comprising at least two vinyl unsaturations and one or a number of aromatic rings which exhibits a structural stress-hardening.

Abstract: Thermoplastic composition comprising at least:a polyolefin (A),a thermoplastic polymer (B), andat least one compound (C) derived from functional compound(s) (D) containing one or more groups chosen from carbon-carbon double and triple bonds and substituted carboxylic groups, obtained by melt blending the polymers (A) and (B) in the presence of the compounds (D).

Abstract: Process for the synthesis of polyamides by polycondensation in a closed reactor of one or a number of dicarboxylic acids with a diamine compound containing not less than 60 mol % of-m-xylyenediamine, in which all the amount of diamine compound stoichiometrically necessary for the polycondensation reaction is quickly brought into contact with the molten acid, the temperature of the reaction mixture is raised to a value greater than the melting point of the polyamide produced, the pressure is only allowed to rise to a value sufficient to prevent solidification of the reaction mixture and a substantial loss of diamine compound and, at the end of the reaction, the pressure of the reaction mixture is reduced and the polyamide formed is recovered.