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 presently claimed invention comprises a biopolymer nanoparticle for drug delivery wherein the nanoparticle comprises a homogeneous blend of an aliphatic polyester polymer blended with a polyether, a lipophilic or polypeptide drug and a biocompatible cholesterol interacting agent for preserving the activity of the drug administered to the patient while at the same time controlling the release of the drug. Methods for making the homogeneous drug delivery nanoparticles are also disclosed.
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:
This process is characterized by the fact that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature that can be as low as 0.degree. C., in the presence of an initiation system including: at least one compound generating radicals, other than bromofluorene, and at least one catalyst consisting of a complex of palladium in the 0 oxidation state, denoted by the following formula (I): Pd(0)L.sup.1 L.sup.2 L.sup.3 L.sup.4 in which each of L.sup.1, L.sup.2, L.sup.3 and L.sup.4, which are identical or different, denotes a ligand which may be a chiral ligand, which is chosen from PRR'R", P(OR)(OR')(OR"), NRR'R", ORR', SRR', SeRR', AsRR'R", SbRR'R", where each of R, R' and R" independently denotes a C.sub.1 -C.sub.14 alkyl group, optionally substituted, or an optionally substituted aromatic group, it being possible for at least two of these ligands to be joined to one another by one or more divalent radicals.
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:
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:
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 process for the controlled radical (co)polymerization of (meth)acrylic and/or vinyl monomers is characterized in that the bulk, solution, emulsion or suspension polymerization or copolymerization is carried out, at a temperature at which can fall to 0.degree. C., of at least one of the said monomers in the presence of an initiating system comprising a radical-generating compound and at least one catalyst composed of a metal complex containing a ligand of the type�4-R.sup.3 -2,6-(CH.sub.2 NR.sup.1 R.sup.2).sub.2 C.sub.6 H.sub.2 !--(I)in which: R.sup.1 and R.sup.2, which are identical or different, represent a branched or unbranched C.sub.1 -C.sub.4 alkyl group or a phenyl group or alternatively R.sup.1 and R.sup.2 form, with the nitrogen atom to which they are connected, a cyclic amine or alternatively the two R.sup.2 groups, taken together, form a polymethylene bridge and R.sup.3 represents a hydrogen atom, an alkyl or benzyl group or an electron-donating or electron-withdrawing functional group.
摘要:
This process is characterized in that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature which may be as low as 0.degree. C., in the presence of an initiator system comprising at least one non-peroxy radical-generator compound and at least one catalyst consisting of a metal complex represented by formula Ma.sub.a (L).sub.n in which M represents Rh, Co or Ir; A represents, a halogen or a pseudohalogen; the groups L, which may be identical or different, each represent a ligand which may be a chiral ligand, which is chosen from cyclooctadiene, PRR'R", P(OR) (OR') (OR"), NRR'R", ORR', SRR', SeRR', AsRR'R", SbRR'R", each radical R, R' and R" independently representing an optionally substituted C.sub.1 -C.sub.14 alkyl group or an optionally substituted aromatic group, it being possible for at least two of these ligands to be joined together by one or more divalent radicals; a is an integer such that 1.ltoreq.a.ltoreq.3 ; n is an integer such that 1.ltoreq.n.ltoreq.5, and in the absence of activator.
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.