摘要:
The present invention provides dispersible carbon particles and a process for the preparation of dispersible carbon particles. In certain embodiments, the process of the present invention comprises polymerizing monomers from a carbon particle, wherein the carbon particle comprises one or more attached groups comprising one or more transferable atoms or groups. At least a portion of the monomers comprise at least one reactive or ionizable functional group capable of conversion into ionic functional groups. Ionic functional groups enhance the dispersity of the carbon particle in the desired medium, such as the dispersity of carbon black particles in water or aqueous solutions. The process of the present invention may further include converting at least a portion of the reactive or ionizable functional groups into ionic functional groups. The ionic groups may be quaternary ammonium groups, carboxylic acid groups, phosphonium groups, sulfonium groups, iodonium groups or salts thereof.
摘要:
The present invention relates to biocidal articles. In an embodiment the biocidal article comprises a plurality of polymers having biocidally active groups. The polymers are attached to a surface and may have a polydispersity less than 3. The biocidally active groups may comprise at least one of a quaternary ammonium salt, a quaternary phosphonium salt or a chloroamine. The attached polymers may be any microstructure, topology or composition, such as, a homopolymer, block copolymer, multiblock copolymer, a random copolymer, graft polymer, a branched or a hyperbranched polymer, and a gradient copolymer. The present invention also comprises a process for the preparation of a biocidal article. Embodiments of the process comprise polymerizing radically polymerizable monomers from an initiator attached to a surface, wherein at least a portion of the monomers comprise a group capable of being converted to a biocidally active group, and converting the group to the biocidally active group.
摘要:
The use of concurrent reverse and normal initiation processes in an ATRP enables the use of highly active catalysts under “reverse ATRP” conditions and leads to the synthesis of well-defined polymers with low molecular weight distributions while employing much lower levels of the transition metal in the system. This dual activation/initiating system allows use of active catalysts that are added to the reaction in an oxidatively stable form. The benefits of this dual initiating system can be attained in bulk, solution and multi-phase ATRP processes, including emulsions, miniemulsions and polymerization from surfaces.
摘要:
A new polymerization process (atom transfer radical polymerization, or ATRP) based on a redox reaction between a transition metal (e.g., Cu(I)/Cu(II), provides “living” or controlled radical polymerization of styrene, (meth)acrylates, and other radically polymerizable monomers. Using various simple organic halides as model halogen atom transfer precursors (initiators) and transition metal complexes as a model halogen atom transfer promoters (catalysts), a “living” radical polymerization affords (co)polymers having the predetermined number average molecular weight by &Dgr;[M]/[I]0 (up to Mn>105) and a surprisingly narrow molecular weight distribution (Mw/Mn), as low as 1.15. The participation of free radical intermediates in ATRP is supported by end-group analysis and stereochemistry of the polymerization. In addition, polymers with various topologies (e.g., block, random, star, end-functional and in-chain functional copolymers [for example, of styrene and methyl (meth)acrylate]) have been synthesized using the present process. The polymeric products encompassed by the present invention can be widely used as plastics, elastomers, adhesives, emulsifiers, thermoplastic elastomers, etc.
摘要:
A process for controlled coupling and chain extension, or atom transfer condensation polymerization, of molecules containing one or more radically transferable atoms or groups is provided, wherein transition metal compounds, optionally partially in the zero oxidation state, various ligands, counterions, and solvents are preferentially employed to preferentially give coupled and chain extended products that no longer contain a radically transferable atom or group.
摘要:
A new polymerization process (atom transfer radical polymerization, or ATRP) based on a redox reaction between a transition metal (e.g., Cu(I)/Cu(II), provides “living” or controlled radical polymerization of styrene, (meth)acrylates, and other radically polymerizable monomers. Using various simple organic halides as model halogen atom transfer precursors (initiators) and transition metal complexes as a model halogen atom transfer promoters (catalysts), a “living” radical polymerization affords (co)polymers having the predetermined number average molecular weight by &Dgr;[M]/[I]0 (up to Mn>105) and a surprisingly narrow molecular weight distribution (Mw/Mn), as low as 1.15. The participation of free radical intermediates in ATRP is supported by end-group analysis and stereochemistry of the polymerization. In addition, polymers with various topologies (e.g., block, random, star, end-functional and in-chain functional copolymers [for example, of styrene and methyl (meth)acrylate]) have been synthesized using the present process. The polymeric products encompassed by the present invention can be widely used as plastics, elastomers, adhesives, emulsifiers, thermoplastic elastomers, etc.
摘要:
A process is provided for the preparation of (co)polymer emulsions or suspensions from a full range of free radically (co)polymerizable monomers, wherein the (co)polymers exhibit the characteristics of "living" polymerization, including one or more of predictable molecular weights, narrow or controllable molecular weight distributions and a variety of polymer architectures, including the roles of surfactants, catalyst and ligands, several initiation methods, and methods for catalyst removal from the emulsions or suspensions made, and the (co)polymer emulsions and suspensions made thereby.
摘要:
A method of chemically modifying the poly (methyl methacrylate) (hereinafter "PMMA") clad surface of an optical fiber to introduce amino groups. N-butyl lithium in a suitable organic solvent with ethylene diamine is applied to the clad surface of the optical fiber in a substantially oxygen-free atmosphere, such as nitrogen, at approximately 10.degree. C. to 40.degree. C. for about one to two hours. A pH-sensitive dye with isothiocyanate functionality can be bounded to the modified clad surface resulting in a pH sensor based on fiber optics.
摘要:
A polymer formed by controlled radical polymerization includes groups that can be modified after controlled radical polymerization to form a radical. The polymer can be the reaction product of a controlled radical polymerization of radically polymerizable monomers, wherein at least one of the radically polymerizable monomers includes at least one group that can be modified after the controlled radical polymerization to form a radical.
摘要:
A core-shell composite particle for incorporation into a composite wherein the composite has improved transparency is disclosed. The core-shell composite particle includes a core material having a first refractive index and a shell material having a second refractive index where the core-shell particle has an effective refractive index determined by the first refractive index and the second refractive index. The effective refractive index is substantially equal to the refractive index of the envisioned embedding medium. Methods of forming the core-shell particles are also disclosed.