376 results about "Multiblock copolymer" patented technology

A composition for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

A composition for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

This invention relates to high melting polyolefin copolymers suitable as thermoplastic elastomers and catalysts and methods for their synthesis. These elastomeric olefin copolymers are characterized by a mole fraction of crystallizable component Xc from about 30 to about 99%; low glass transition temperatures, below -20° C., and typically below -50° C.; melting points above about 90° C.; high molecular weights; a molecular weight distribution MW / Mn< / =10; and a narrow composition distribution between chains of < / =15%. The novel copolymers of the invention range from reactor blends to multiblock copolymers that can be sequentially fractionated into fractions of differing crystallinities, which fractions nevertheless show compositions of comonomers which differ by less than 15% from the parent polymer (reactor product). The invention also relates to a process for producing such copolymers by utilizing an unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalyst that is capable of interconverting between states with different copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where ri>rf the polymer can be characterized as multiblock; where ri<rf, the result is a polymer blend and where ri / rf is close to 1, the resulting polymer is a mixture of blend and multiblock. The metallocene catalysts of the invention are able to interconvert between more than two states, with embodiments of four states being shown in FIG. 2.

Anti-blocking polymer compositions comprise at least one ethylene / α-olefin interpolymer and at least one anti-blocking agent comprising an amide. The ethylene / α-olefin interpolymers are a multi-block copolymer comprising at least one soft block and at least one hard block. The anti-blocking agent can be erucamide or other amides. The anti-blocking polymer composition has a pellet blocking strength of equal to or less than 100 lbs / ft2 (4800 Pa). When the anti-blocking polymer composition is made into a film, the film has a blocking force of less than about 100 grams, measured according to ASTM method D-3354.

This invention relates to high melting polyolefin copolymers suitable as thermoplastic elastomers and catalysts and methods for their synthesis. These elastomeric olefin copolymers are characterized by a mole fraction of crystallizable component Xc from about 30 to about 99%; low glass transition temperatures, below -20° C., and typically below -50° C.; melting points above about 90° C.; high molecular weights; a molecular weight distribution MW / Mn< / =10; and a narrow composition distribution between chains of < / =15%. The novel copolymers of the invention range from reactor blends to multiblock copolymers that can be sequentially fractionated into fractions of differing crystallinities, which fractions nevertheless show compositions of comonomers which differ by less than 15% from the parent polymer (reactor product). The invention also relates to a process for producing such copolymers by utilizing an unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalyst that is capable of interconverting between states with different copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where ri>rf the polymer can be characterized as multiblock; where ri<rf, the result is a polymer blend and where ri / rf is close to 1, the resulting polymer is a mixture of blend and multiblock. The metallocene catalysts of the invention are able to interconvert between more than two states, with embodiments of four states being shown in FIG. 2.

Non-linear multiblock copolymer-drug conjugates for the treatment and prevention of diseases and disorders of the eye are provided. The polymer-drug conjugates can form nanoparticles, microparticles, and implants that are capable of effectively delivering therapeutic levels of one or more active agents for an extended period of time. Administration to the eye of an active agent in the form of a non-linear multiblock copolymer-drug conjugate produces decreased side effects when compared to administration of the active agent alone. Also provided are methods of treating intraocular neovascular diseases, such as wet age-related macular degeneration as well as diseases and disorders of the eye associated with inflammation, such as uveitis.

Disclosed herein are stealthy polymeric biodegradable nanospheres each comprising: (i) a polyester-polyethylene multiblock copolymer; (ii) optionally a polyester entangled with the multiblock copolymer to give rigidity to the nanospheres; and (iii) optionally a pharmaceutical compound incorporated therein. Also disclosed is the use of such nanospheres for the preparation of a medicament having a long-term and non-toxic release of a pharmaceutical compound into a mammal, and the method for preparing a stealthy polymeric biodegradable nanospheres.

Copolymers, especially multi-block copolymer containing therein two or more segments or blocks differing in chemical or physical properties, are prepared by polymerizing propylene, 4-methyl-1-pentene, or other C4-8α-olefin and one or more copolymerizable comonomers, especially ethylene in the presence of a composition comprising the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

This patent discloses the synthesis of a multi-block copolymer containing poly(amino acids) (PAA) and a hydrophilic polymer which are degradable under physiological conditions. Control over the degradation rate of the obtained copolymers is achieved by introducing ester, amide or urethane groups as a biodegradable linkage connecting the PAA and the hydrophilic polymer. The biodegradable multi-block copolymers display high transfection efficiency in plasmid delivery with low cytotoxicity.

The present invention relates to the field of polymer chemistry and more particularly to multiblock copolymers and micelles comprising the same.

Foamable compositions and foams comprise at least an ethylene / α-olefin interpolymer. The foam has a density from greater than 150 to about 500 kg / m3. The foamable compositions further comprise a blowing agent and a crosslinking agent. The ethylene / α-olefin interpolymers are a multi-block copolymer comprising at least one soft block and at least one hard block. Methods of making the foamable compositions and foams; and foamed articles made from the foams are also described.

A composition for use in forming a multi-block copolymer from a single polymerizable monomer, said copolymer containing therein two or more segments or blocks differing in branching index, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first olefin polymerization catalyst, (B) a second olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, at least one of catalyst (A) or catalyst (B) being capable of forming a branched polymer by means of chain walking or reincorporation of in situ formed olefinic polymer chains, and (C) a chain shuttling agent.

A process for preparing polymers, especially multi-block copolymer containing therein two or more segments or blocks differing in chemical or physical properties, by contacting propylene, 4-methyl-1-pentene, or other C4-8 α-olefins and one or more copolymerizable comonomers, especially ethylene in the presence of a composition comprising the admixture or reaction product resulting from combining:(A) a first metal complex olefin polymerization catalyst,(B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and(C) a chain shuttling agent.

The present invention discloses a degradation type marine anti-fouling material, a preparation method and an application thereof. According to the present invention, a polyol with a characteristic of controllable degradation, isocyanate and a chain extender react to form a multi-block copolymer, wherein the multi-block copolymer can be degraded in seawater so as to flush a new surface, such that adhered marine organisms fall down; the multi-block copolymer can be applicable for preparation of a marine anti-fouling coat; the composition and the ratio of the polymers are adjusted to control crystallinity, and hydrophilicity / hydrophobicity of the polyol so as to effectively regulate degradation properties; with introductions of the isocyanate and the chain extender, excellent mechanical property and adhesion of the polyurethane are combined under the premise of assurance of controllable degradation performance; the degradation type marine anti-fouling material of the present invention can be dissolved in conventional xylene or an alcohol solvent, has good surface self-renewal performance and good mechanical properties, and does not contain any anti-fouling agents; and the method of the present invention has characteristics of simple process and low cost, and is suitable for industrial production.

A self-wrapping dilatation balloon comprising a multiblock copolymer having high elasticity and elastic recovery from nominal strains greater than about 30% is described. Also described herein, is a polymeric extrudate for making a dilatation balloon comprising a multiblock copolymer having tensile strength in the range of about 50 MPa to about 450 MPa, strain at break in the range of about 50% to about 600% and substantially complete elastic recovery from nominal strains of at least about 30%. The extrudate has phase-separated microdomains that are macroscopically aligned in parallel, perpendicular, transverse or a combination thereof. Also described herein is a process for producing a polymeric extrudate for use as a dilatation balloon. The process comprises extruding a multiblock copolymer mixture or composition to form an extrudate. The extruding is done such that the extrudate has phase-separated microdomains that are macroscopically aligned in parallel, perpendicular, transverse or a combination thereof. After extrusion, the process optionally comprises the steps of drawing and coagulating the extrudate.