Atofina

Elf Atochem S.a.

Denis Bertin

Bernard Boutevin

Pascal Nicol

Patrice Robert

Denis Germain

Alain Bouilloux

Laurent Teze

Jean-Jacques Robin

Thierry Vivier

The invention relates to a process for the polymerization of at least one monomer which can be polymerized via a radical route, in the presence of a stable free radical and of a polymerization initiator, such that, per 100 mol of monomer, the molar amounts of stable radical (SFR) and of initiator (INIT) are such that [(SFR)&#xd7;F]/[(INIT)&#xd7;F]&#x3c;0.15 and F&#xd7;(SFR)&#x3c;0.2 mol, in which Frepresents the functionality of the stable free radical and Frepresents the functionality of the initiator. The process according to the invention has advantageous kinetics, allows the production of grafted or block copolymers and can be carried out in an extruder.

Controlled radical polymerization process using a small amount of stable free radical

This process for the production of a controlled-rheology resin of a propylene homopolymer or copolymer or a composition that comprises a propylene homopolymer or copolymer in the absence of a functional monomer, whereby said process brings about an increase of the fluidity index of the resin by cuts of the chains, is characterized by the fact that at least one stable free radical is incorporated into said resin in the viscous state, since a solid product that has an increased fluidity index is formed. In particular, the stable free radical or radicals is or are selected from among nitroxyl radicals, comprising at least one &boxH;N&mdash;O&prime; group.

Method for the production of a controlled rheological polypropylene resin

The invention relates to a thermoplastic composition comprising: a matrix-forming thermoplastic polymer (M), rigid nodules obtained by radical polymerization, and optionally an impact modifier (S). It also relates to a process comprising, in a first stage, forming a homogeneous solution of precursor of the nodules in the thermoplastic (M) in the molten state, in a second stage, introducing the initiator while remaining at a temperature below which the initiator becomes active, and, in a third stage, heating to a temperature sufficient to cause crosslinking of the precursor and to form rigid nodules while kneading the composition, the impact modifier being introduced during the first or the second stage.

Thermoplastic resin compositions comprising a rigid dispersed phase

Composition based on an ethylene-vinyl alcohol copolymer and its use

Polymerization in the presence of a stable free radical and of a free radical initiator

Copolymer grafted via radical polymerization in the presence of stable radicals, its preparation and its uses

Polymerization in the presence of a stable free radical and of an iniferter

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Motteville, France

Denis Bertin