Elf Atochem S.a.

Philippe Bayard

Philippe Teyssie

Bruno Vuillemin

Philippe Heim

Jin-shan Wang

Roger Fayt

Sunil K Varshney

Jinshan Wang

Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Anionically copolymerized living random (meth) acrylic copolymers and

Anionically copolymerized living random (meth)acrylic copolymers and

An initiation system for the anionic polymerization of (meth)acrylic monomers and, optionally, nonacrylic vinyl monomers is disclosed. The initiation system comprises (1) a functional initiator and (2) an alkali metal alcoholate having the formula R'OM', in which M' is an alkali metal and R' is a group R.sup.1 (OR.sup.2).sub.m where R.sup.1 is a C.sub.1 -C.sub.6 alkyl or arylalkyl radical, R.sup.2 is a C.sub.2 -C.sub.4 alkylene radical and m is equal to 1, 2 or 3. The initiation system is applied to the formation of (meth)acrylic homopolymers and block copolymers of (meth)acrylic monomers and, optionally, nonacrylic vinyl comonomers.

Initiation system for the anionic polymerisation of (meth)acrylic

A diblock copolymer obtained by polymerizing acrylic, methacrylic or nonacrylic vinyl monomers in the presence of a polymerization initiating amount of an initiation system including (1) at least one functional initiator and (2) an alkali metal alcoholate. The alcoholate has the formula:

Initiation system for the anionic polymerization of (meth)acrylic

Thermoplastic, elastomeric, conjugated diene (e.g., butadiene)/methyl methacrylate block copolymers having elevated Tg and improved impact strength, well suited as polymer impact strength-modifiers and for conversion into pressure-sensitive adhesives, are prepared by (a) anionically polymerizing a conjugated diene monomer in an apolar solvent medium to provide a living polydiene, (b) next adding an alkali metal alkoxyalcoholate ligand to the medium comprising the living polydiene thus formed, (c) block copolymerizing the step (b) living polydiene with methyl methacrylate comonomer to provide a living copolymer, and (d) reacting the step (c) living copolymer with at least one protonic compound, e.g., water, alcohol and/or acid, and completing the polymerization thereof, with the proviso that polymerization of the conjugated diene and the methyl methacrylate comonomers is strictly carried out in the apolar solvent medium, in particular in toluene, benzene or ethylbenzene.

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Stavelot, Belgium

Philippe Bayard