High-impact vinylaromatic polymer obtained from a rubber bearing a group which generates a stable free radical
AssigneeAtofina
InventorsJean-Marc Boutillier, Nathalie Forges
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Abstract
The invention relates to a process for preparing a composition comprising a vinylaromatic polymer matrix and particles of rubber, which comprises a step of polymerizing at least one vinylaromatic monomer in the presence of a rubber comprising a group which generates a stable free radical. The process makes it possible to obtain morphologies other than salami morphologies, such as the labyrinth, onion or capsule morphology, with the aim, for example, of enhancing the gloss of the high-impact vinylaromatic polymer.
Claims29
A process for preparing a rubber which carries a group which generates a stable free radical, including a step of heat treatment of an elastomer in the presence of a stable free radical, of a free-radical initiator which is capable of withdrawing a proton from the elastomer, and of a solvent and in the absence of vinylaromatic monomer, such that the rubber carries on average from 0.1 to 10 groups which generate a stable free radical per rubber chain.
Rubber, comprising on average from 0.1 to 0.9 groups which generate stable free radicals per rubber chain.
Composition comprising a matrix of vinylaromatic polymer surrounding particles of rubber and comprising a stable free radical and/or a group which generates a stable free radical, forming part of a polymer chain, characterized in that at least some of the rubber particles are in labyrinth form.
Composition comprising a matrix of vinylaromatic polymer surrounding particles of rubber and comprising a stable free radical and/or a group which generates a stable free radical, forming part of a polymer chain, characterized in that at least some of the rubber particles are in onion form.
Composition comprising a matrix of vinylaromatic polymer surrounding particles of rubber and comprising a stable free radical and/or a group which generates a stable free radical, forming part of a polymer chain, characterized in that at least some of the rubber particles are in capsule form.
Composition comprising a matrix of vinylaromatic polymer surrounding particles of rubber and comprising a stable free radical and/or a group which generates a stable free radical, forming part of a polymer chain, characterized in that at least 95% of the rubber particles are in capsule form.
A process for preparing a rubber which carries a group which generates a stable free radical, including a step of heat treatment of an elastomer in the presence of a stable free radical, of a free-radical initiator which is capable of withdrawing a proton from the elastomer, and of a solvent and in the absence of vinylaromatic monomer, such that the rubber carries on average from 0.1 to 0.9 groups which generate a stable free radical per rubber chain, wherein the number (SFR) of moles of stable free radical, the number (INIT) of moles of free-radical initiator and the number (ELAST) of moles of elastomer are such that:
- F INIT × ( INIT ) F SFR × ( SFR ) is between 0.1 and 10 , ( ELAST ) ( SFR ) × F SFR is between 0.1 and 10 ,
- FSFR representing the functionality of the stable free radical, meaning the number of sites on the same stable free radical molecule which exhibit the stable free radical state, and FINIT representing the functionality of the free-radical initiator, meaning the number of free radicals which each molecule of initiator is capable of generating, and the elastomer has a number-average molecular mass of from 50,000 to 350,000 and a weight-average molecular mass of from 100,000 to 500,000, and the elastomer is a homopolybutadiene.
Dependencies are inferred from the claim text.