摘要:
The present invention relates to a polymerization process for the control of the microstructure of polymers and to novel copolymers. An embodiment of the present invention relates a process of polymerizing first and second monomers in the presence of a complex comprising at least one of the monomers. The presence of the complex modifies the relative reactivity, or cross propagation rate constants, of the monomers in copolymerization reactions. Embodiments of the present invention allow the synthesis of polymers with novel stereochemistry and monomer sequence distribution, for example, but not limited to, copolymers with at least one segment of alternating monomers, a controlled molecular weight and narrow molecular weight distribution, or a segment of high concentration of the first monomer.
摘要:
Further improvements have been made in processes for controlled polymerization of free radically (co)polymerizable monomers mediated by a transition metal complex participating in a redox reaction which involves transfer of a radically transferable atom or group to and from an initiator or dormant polymer and the growing active polymer chain ends. Two improvements involve the choice of counterion in the transition metal complex. In one improvement the transition metal is held in close conjunction with a solid support through interaction with a counterion directly attached to the support. This cognition also allows for improvements in catalyst utilization including catalyst recovery and recycle. In another improvement, particularly suitable for controlled polymerization of certain monomers with an expanded range of transition metals, the function of counterion and ligand in the development of the transition metal based catalyst is superseded by use of salt containing a soluble organic counterion. These and other process improvements have been employed to prepare an extended range of novel polymeric materials and novel processes for the preparation of functional polymers including a novel catalytic Atom Transfer Coupling Reaction.
摘要:
The invention generally relates to a method of inhibiting polymerization of vinyl aryl monomers, a process for increasing number average molecular weight of a polystyrene, and to an inhibitor composition useful therein.
摘要:
Methods for conducting controlled grafting-from radical polymerizations from biomolecules under conditions that are biologically compatible are described. The methods provide biomolecule-polymer conjugates with highly controlled structures and narrow polydispersities under aqueous reaction conditions and biological temperatures. Biomolecules, such as proteins and nucleotides can be conjugated to polymers with high levels of control.
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. A compound includes a first group that is stimulated upon application of energy to the molecule to tether the molecule to a surface or to another polymer chain and a second group comprising a controlled radical polymerization initiator functionality. A block copolymer includes at least a first segment to impart a predetermined functionality to a target surface and at least a second segment including functional groups to interact with the targeted surface to attach the block copolymer to the surface. The first segment can free of functional groups that interact with the surface to attach the block copolymer to the surface.
摘要:
The present invention relates to a polymerization inhibitor composition and a method of inhibiting polymerization of distillable monomers in liquid and evaporated/condensed phases with the polymerization inhibitor composition. The polymerization inhibitor composition is useful for inhibiting polymerization of the distillable monomers during manufacture, purification (e.g., distillation), handling, and storage thereof.
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.
摘要:
The invention is directed to a microemulsion polymerization comprising adding a polymerization catalyst precursor, such as a transition metal complex in the higher of two accessible oxidation states, an ATRP initiator, and an organic solvent to an aqueous solution to form an emulsion. Radically polymerizable monomers and a reducing agent may then be added to the emulsion. The reducing agent converts the catalyst precursor to a catalyst for polymerization of the first monomer from the initiator. In certain embodiments the organic solvent may comprise radically polymerizable monomers. The aqueous solution may comprise a surfactant. Further embodiments are directed to an ah initio polymerization process comprising adding a polymerization catalyst precursor; an ATRP initiator, and an organic solvent to an aqueous solution to form an emulsion, wherein the organic solvent comprises second radically polymerizable monomers, adding a reducing agent to convert the catalyst precursor to a catalyst for polymerization of the first radically polymerizable monomer from the initiator; and adding first radically polymerizable monomers to the emulsion.
摘要:
A polymerization process comprising initiating a first polymerization of monomers using an initiator functionalized with an ATRP initiating site, wherein the first polymerization is selected from the group of cationic polymerization, anionic polymerization, conventional free radical polymerization, metathesis, ring opening polymerization, cationic ring opening polymerization, and coordination polymerization to form a macroinitiator comprising an ATRP initiating site and further initiating an ATRP polymerization of radically polymerizable monomers using the macroinitiator comprising an ATRP initiating site. Novel block copolymers may be formed by the disclosed method.
摘要:
Improved processes for atom (or group) transfer radical polymerization (ATRP) and novel polymers have been developed and are described. In certain embodiments, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly alternating monomer sequence are described. Novel copolymers comprising a least one polymeric branch or polymeric block with a gradient monomer structure are described. Additionally, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly periodic monomer sequence are also described. Novel copolymers having a water soluble backbone and at least two hydrophobic polymeric branches grafted to the water soluble backbone are also described.