摘要:
The invention concerns a method for forming a coating on conductive particles by grafting a polymer and/or a copolymer of the particles from a bath containing at least a monomer from which the polymer and/or copolymer is formed. The method consists of producing the grafting by electrochemical reduction of the monomer in an electrolytic solution, where at least a cathode and an anode are provided, and containing an aprotic solvent, a support electrolyte and the monomer(s) required for polymerizing or copolymerizing the coating, by suspending the particles and moving the solution so as to produce an intermittent contact between the particles and the cathode, and to form, by polymerization or copolymerization, the coating on the particles by applying an electric potential.
摘要:
A film of a composite material is deposited by electropolymerization onto electrically conductive surface. A mixture comprising a monomer, a substance forming a dopant, a supporting electrolyte and a solvent is subjected to electrolysis in which the conductive surface to be coated is used as either cathode or anode. The cathode or anode is polarized to a potential between the electron transfer between the electrically conductive surface and the monomer. Prior to electrolysis, a solution is made from the mixture containing the substance forming a dopant either as anion, cation, molecule, and/or as undissociated complex.
摘要:
A process for depositing by electropolymerization an organic film onto an electrically conductive surface, wherein use is made of a mixture comprising (a) at least one monomer suited for forming a polymer onto said surface, (b) at least one material which can be linked to said polymer, (c) a supporting electrolyte and (d) a solvent, said process comprising the use, as material to be linked to said polymer, of a reactive substance which can react chemically with the growing polymeric chains formed starting from the monomer.
摘要:
A method for making composites uses electrochemical polymer or copolymer coating of a carbon-based support by using a reaction system including (a) at least a monomer capable of forming a polymer on said support, (b) an aprotic solvent and (c) an electrolyte providing the resulting organic medium with an electrical conductivity for conducting therein electrolysis. The carbon support permanently forms the cathode, by applying either a potential or an electric current bringing the reaction system into the passivation zone corresponding to the first inhibition peak. The method forms a polymer grafted on the support.
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:
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:
Unsubstituted oxepane-diones useful as monomers for the production of polymers, process for the synthesis thereof by oxidation of unsubstituted cyclohexanediones, process for the preparation of polyesterketone polymers by polymerization of cyclic esterketones and polyesterketone polymers so obtained.
摘要:
An aliphatic polyester and/or copolyester, obtained from a polyreaction of at least one monomer from the group comprising lactides, lactones, cyclic carbonates and cyclic anhydrides. To be able to prepare the aliphatic polyester and/or copolyester a reaction mixture is used which contains at least one catalyst of the general formula (M) (X.sub.1, X.sub.2 . . . X), M being a metal selected from the group 3 to 12 of the periodic system (X.sub.1, X.sub.2 . . . X.sub.m) being a substituent selected from one of the families of alkyls, aryls, oxides, carboxylates, halogenides, alkoxides and compounds with elements from group 15 and/or 16 of the periodic system, m being an integer in the range of from 1 to 6, and n being an integer in the range of from 0 to 6, and which also contains a co-catalyst of the general formula (Y) (R.sub.1, R.sub.2 . . . R.sub.q).sub.p, Y being an element selected from the group 15 or 16 of the periodic system. (R.sub.1, R.sub.2 . . . R.sub.q) being a substituent selected from one of the families of the alkyls, aryls, oxides, halogenides, oxyalkyls, aminoalkyls, thiolkyls, phenoxides, aminioaryls, thioaryls, and q and p corresponding to the values for m and n.
摘要:
The present invention relates to microparticles containing an active principle against malaria, such as primaquine, one of its amino acid derivatives, or their conjugates with a hepatotropic vector or their pharmaceutically acceptable salts, and a biocompatible and biodegradable polymer controlling the kinetics of release of the active principle, like (DL)polylactide. The invention also relates to pharmaceutical compositions comprising microcapsules according to the invention. Lastly, the invention relates to processes for the preparation of microparticles as mentioned above, the processes comprising: dissolving the polymer in a volatile solvent, adding to this solution the active principle and possibly a substance regulating the size of the microparticles, and at the end of evaporation, recovering the microparticles by centrifugation and filtration.
摘要:
The present invention relates to an initiation system composed of the reaction product of at least one cyclic siloxane and at least one organometalic compound of sufficient reactivity to open the siloxane ring. Application of the present invention is to the preparation of homopolymers of (meth)acrylic, vinylaromatic or diene monomers, random or block copolymers of these monomers and, in particular, application to poly(methylmethacrylate) with a high content of isotactic triads.