Abstract: A process for manufacturing a star shaped block polymer of formula (PA--PB--PC).sub.n --N--(PD--PE).sub.m wherein PA, PB and PC are respectively vinylaromatic/methacrylic blocks, acrylic blocks and methacrylic blocks. PD is a polymer block selected from vinylaromatic and/or methacrylic monomer units, PE is an acrylic polymer block, n is 2 to 20 and m is 0 to 18 with the proviso that m+n is .ltoreq.20. The process proceeds by anionic polymerization in the presence of a monofunctional initiator of formula (II),(R).sub.p --Mwherein M is an alkali or alkaline earth metal, p is 1 or 2 and R is a straight or branched alkyl radical having 2 to 6 carbon atoms or a C.sub.1 to C.sub.6 substituted alkyl radical.

Abstract: This invention relates to an initiating system for the anionic polymerization of acrylic monomers, and where necessary vinyl comonomers, including at least one R-M initiator in which M is a metal chosen from among the alkali and alkaline earth metals and R is a linear or branched chain alkyl, aryl, or arylalkyl radical. The polymerization may also take place in the presence of at least one R.sub.1 OM.sub.1 alkali metal alcoholate, in which R is an linear or branched chain alkyl, aryl, or arylalkyl radical and M.sub.1 is an alkali metal, on the condition that when M.sub.1 is lithium, then R is an aryl or arylalkyl radical. This invention also related to a process for the polymerization of primary, secondary, or tertiary alkyl acrylates, and possibly of vinyl comonomers, in the presence of the initiating system described above.

Abstract: 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.

Abstract: 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:R'OM'in which M' is an alkali metal and R' has the formula:R.sup.1 (OR.sup.2).sub.min which R.sup.1 is a linear or branched alkyl radical containing from 1 to 6 carbon atoms or an arylalkyl radical, R.sup.2 is a linear or branched alkylene radical containing from 2 to 4 carbon atoms, and m is the integer 1, 2 or 3.

Abstract: Novel N-substituted maleimide homopolymers having a number-average molecular weight ranging from 12,000 to about 100,000 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one organometallic polymerization initiator which comprises sec-butyllithium, a sodium alcoholate, diphenylmethylpotassium, naphthalenelithium or naphthalenesodium, and novel N-substituted maleimide homopolymers having a polydispersity index ranging from 1.1 to 1.5 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one alkali metal organometallic polymerization initiator and at least one inorganic or organic salt of an alkali or alkaline earth metal; novel block copolymers include blocks of the above maleimido homopolymers and, e.g., blocks of an acrylic or methacrylic polymer.

Abstract: The initiating system for the anionic polymerization of acrylic monomers, and where necessary, vinyl comonomers, including at least one R-M initiator in which M=a metal chosen from among the alkaline and alcaline earth metals and R=an alkyl with a linear or branched chain at C.sub.2 -C.sub.6 or aryl or arylalkyl, is characterized by the fact that the polymerization takes place in the presence also of at least one R.sub.1 OM.sub.1 alkaline metal alcoholate, in which R=an alkyl with a linear or branched chain at C.sub.1 -C.sub.6 or aryl or aryalkyl and M.sub.1 =an alkaline metal, on condition that when M.sub.1 is lithium, then R=an aryl or arylalkyl. Said process for the polymerization of primary, secondary, or tertiary alkyl acrylates, and possibly of vinyl comonomers, is characterized by the fact that the polymerization takes place in the presence of an initiating system as described above.

Abstract: Novel N-substituted maleimide homopolymers having a number-average molecular weight ranging from 12,000 to about 100,000 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one organometallic polymerization initiator which comprises sec-butyllithium, a sodium alcoholate, diphenylmethylpotassium, naphthalenelithium or naphthalenesodium, and novel N-substituted maleimide homopolymers having a polydispersity index ranging from 1.1 to 1.5 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one alkali metal organometallic polymerization initiator and at least one inorganic or organic salt of an alkali or alkaline earth metal; novel block copolymers include blocks of the above maleimido homopolymers and, e.g., blocks of an acrylic or methacrylic polymer.

Abstract: The application discloses a functionalized multiblock macromonomer of formula: ##STR1## or of formula: ##STR2## in which formulae: each of the blocks A, B and C represents a sequence of a monomer chosen from the acrylic, vinylaromatic, methacrylic, diene, vinylpyridine, vinylpyrrolidone, alkylene oxide, lactam, lactone and maleimide monomer classes, on condition that at least one of the blocks A and C is chosen from a different class to that of block B and that at least one of the blocks A, B or C is a (meth)acrylic sequence,m, n and p are integers representing the number of monomer units in the sequence under consideration, such that 3.ltoreq.n.ltoreq.1000, 0.ltoreq.m.ltoreq.1000 and 0.ltoreq.p.ltoreq.1000, on condition that m and p are not 0 at the same time, andF is a group terminated by O.sup.-, by OH, by an .alpha.,.beta.-ethylenic unsaturation, or by an oxirane groups.

Abstract: Novel N-substituted maleimide homopolymers having a number-average molecular weight ranging from 12,000 to about 100,000 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one organometallic polymerization initiator which comprises sec-butyllithium, a sodium alcoholate, diphenylmethylpotassium, naphthalenelithium or naphthalenesodium, and novel N-substituted maleimide homopolymers having a polydispersity index ranging from 1.1 to 1.5 are prepared by anionically polymerizing an N-substituted maleimide monomer, in solvent phase, in the presence of at least one alkali metal organometallic polymerization initiator and at least one inorganic or organic salt of an alkali or alkaline earth metal; novel block copolymers include blocks of the above maleimido homopolymers and, e.g., blocks of an acrylic or methacrylic polymer.

Abstract: This system for priming the animic polymerization of (meth)acrylates includes at least one primer of the formula R--M (I) in which M represents a metal selected from alkaline and alkaline earth metals and R represents an alkyl radical with a straight or branched chain containing 2 to 6 atoms of carbon or an aryl radical or an arylalkyl radical. H is characterized in that it further contains at least one organic derivative of an alkaline metal, with the proviso that said organic derivative is neither an alcoholate nor a carboxyl acid ester substituted in position .alpha. by said metal. Applications in the anionic polymerization of (meth)acrylates.

Abstract: Triblock copolymers containing a copolymer having a number-average molecular weight of from 3,000 to 300,000, a molecular weight polydispersity of from 1.05 to 2.0, and an A-B-C structure in which each of the blocks A and C may be a monomer sequence chosen from an acrylic, a vinylaromatic, a methacrylic or a maleimide monomer, and block B may be a monomer sequence chosen from an acrylic, a vinylaromatic or a methacrylic monomer, where at least one of the blocks A and C is different than block B.

Abstract: A process for the polymerization of acrylic monomers and optionally of vinyl comonomers using (i) an initiator of formula (I):R--M (I)in which M denotes a metal selected from the group consisting of alkali metals and alkaline earth metals and R denotes a straight-chain or branched alkyl radical containing 2 to 6 carbon atoms or an aryl radical, and (ii) at least one non-nitrogenous macrocyclic complexing agent.The polymerization process is used to make products of acrylic polymers having a narrow distribution of molecular masses.

Abstract: A process for the polymerization of acrylic monomers and optionally of vinyl comonomers using (i) an initiator of formula (I):R--M (I)in which M denotes a metal selected from the group consisting of alkali metals and alkaline earth metals and R denotes a straight-chain or branched alkyl radical containing 2 to 6 carbon atoms or an aryl radical, and (ii) at least one non-nitrogenous macrocyclic complexing agent.The polymerization process is used to make products of acrylic polymers having a narrow distribution of molecular masses.

Abstract: Block copolymers having a first sequence formed with a conjugated diene or a vinyl substituted aromatic hydrocarbon other than alpha-methylstyrene, a second sequence formed with an acrylic ester, and a linking intermediate sequence formed with alpha-methylstyrene. An anionic polymerization process is used to form these block copolymers.