摘要:
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.
摘要:
Poly(alkyl (meth)acrylates) are inexpensively prepared, even on an industrial scale, by anionically polymerizing at least one alkyl (meth)acrylate monomer in the presence of a lithium-based initiator and in a liquid solvent medium in which the solubility parameter .delta. is less than 20, said initiator comprising an alcoholate having the formula ROLi, wherein R has the formula R.sup.1 (OR.sup.2).sub.m, in which R.sup.1 is a linear or branched alkyl radical having from 2 to 4 carbon atoms, R.sup.2 is a linear or branched alkylene radical having from 2 to 4 carbon atoms, and m is 1, 2 or 3.
摘要:
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.m in 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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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 --M wherein 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.
摘要:
Mechanically strong; heat-resistant and transparent PMMA polymers having a high content of syndiotactic triads, a number average molecular weight ranging from 5,000 to 500,000 and a polydispersity index ranging from 1.01 to 1.5, are prepared by anionically polymerizing methyl methacrylate, characteristically at a temperature of at least 0.degree. C., in the presence of (a) at least one organolithium or organosodium initiator and (b) at least one AlR.sup.1 R.sup.2 R.sup.3 ligand, for example at least one di- or tri-phenoxy alkyl aluminum compound.