The present invention relates to a process for the preparation of a polyethylene wax, the process comprising the steps of providing a catalyst solution, wherein the catalyst solution comprises at least one activating compound, an alkylaluminoxane and a me-tallocene complex, wherein the molar ratio of the activating compound to aluminum comprised in the alkylaluminoxane is from 0.0005 to 0.20; and polymerizing ethylene, by contacting the ethylene and the catalyst solution.

The present invention relates to a process for the preparation of a polyethylene wax, the process comprising the steps of providing a catalyst solution, wherein the catalyst solution comprises at least one activating compound, an alkylaluminoxane and a me-tallocene complex, wherein the molar ratio of the activating compound to aluminum comprised in the alkylaluminoxane is from 0.0005 to 0.20; and polymerizing ethylene, by contacting the ethylene and the catalyst solution.

Provided herein are block copolymers comprising a hydrophilic polymer segment and a hydrophobic polymer segment, wherein the hydrophilic polymer segment comprises a polymer selected from the group consisting of: poly(ethylene oxide) (PEO), poly(methacrylate phosphatidyl choline) (MPC), and polyvinylpyrrolidone (PVP), wherein the hydrophobic polymer segment comprises

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wherein R′ is —H or —CH.sub.3, wherein R is —NR.sup.1R.sup.2, wherein R.sup.1 and R.sup.2 are alkyl groups, wherein R.sup.1 and R.sup.2 are the same or different, wherein R.sup.1 and R.sup.2 together have from 5 to 16 carbons, wherein R.sup.1 and R.sup.2 may optionally join to form a ring, wherein n is 1 to about 10, and wherein x is about 20 to about 200 in total. Also provided are pH-sensitive micelle compositions for therapeutic and diagnostic applications.

The present invention relates to compositions comprising at least one (per)fluoropolyether base oil and at least one polymer obtained by the copolymerization of (per)fluoropolyether (PFPE), tetrafluoroethylene (TFE) and at least one non-homopolymerizable olefin.

The present invention relates to compositions comprising at least one (per)fluoropolyether base oil and at least one polymer obtained by the copolymerization of (per)fluoropolyether (PFPE), tetrafluoroethylene (TFE) and at least one non-homopolymerizable olefin.

Provided is a method making it possible to ensure a gradual release of polymer chains within a liquid medium, the method comprising bringing the liquid medium into contact with specific solid objects formed by polymer chains soluble in the medium and carrying hydrophobic side groups ensuring physical crosslinking between the polymer chains within the solid objects. The released chains may in particular be used as inhibitors of the formation of inorganic or organic deposits (scale inhibitors) within a liquid medium, typically in the field of oil extraction.

A method for synthesizing an aliphatic polyester block copolymer regulated by carbon monoxide. The method uses an organic cobalt metal complex as a convertible catalyst and includes: first regulating an anionic ring-opening copolymerization reaction between an aliphatic acid anhydride and an epoxy compound; then using carbon monoxide as a conversion agent for conversion to obtain a catalyst having a new catalytic active site; and regulating a vinyl monomer to perform active free radical polymerization to obtain an aliphatic polyester block copolymer having a controllable structure. The described synthesis method uses a convertible catalyst and a conversion agent, combines two controllable polymerization reactions which have different but compatible mechanisms, and obtains a block copolymer by means of a “one-pot” reaction.

Disclosed herein are linear block copolymers of formula A-B-A′ or A-B*B-A′, wherein blocks A and A′ are polystyrene blocks, block B is a poly(conjugated diene) block and * is a coupling agent having a vinyl content of from 10-60 mol %. The block copolymers have a polystyrene content of from 20-35 wt. %, relative to the overall weight of the block copolymer, and a molecular weight of from 200,000-300,000 g/mol. The block copolymers can be used with a wide variety of asphalt grades, and are valuable for producing homogeneous polymer modified asphalt compositions having an effective combination of performance properties, such as acceptable viscosity, good elastic response to an applied stress, and a low non-recoverable creep compliance. The combination of vinyl content and polymerization technology allows a high solution concentration during polymerization without excessive processing viscosity.

Disclosed herein are linear block copolymers of formula A-B-A′ or A-B*B-A′, wherein blocks A and A′ are polystyrene blocks, block B is a poly(conjugated diene) block and * is a coupling agent having a vinyl content of from 10-60 mol %. The block copolymers have a polystyrene content of from 20-35 wt. %, relative to the overall weight of the block copolymer, and a molecular weight of from 200,000-300,000 g/mol. The block copolymers can be used with a wide variety of asphalt grades, and are valuable for producing homogeneous polymer modified asphalt compositions having an effective combination of performance properties, such as acceptable viscosity, good elastic response to an applied stress, and a low non-recoverable creep compliance. The combination of vinyl content and polymerization technology allows a high solution concentration during polymerization without excessive processing viscosity.

An amphiphilic copolymer includes a first block, a second block and a linker covalently linking the first block with the second block, wherein the first block is a hydrophilic dendritic polyglycerol derivative having a polyglycerol backbone and carrying a plurality of sulfate or sulfonate residues substituting hydroxyl groups of the polyglycerol backbone, wherein the second block is a hydrophobic block comprising a polymer chosen from the group consisting of polycaprolactone, a polylactic acid polymer, and a copolymer of lactic acid and glycolic acid. The linker comprises a hydrocarbon having at least six consecutive methylene residues and a cleavable entity. The linker is devoid of a triazole-containing residue resulting from a reaction between an alkyne and an azide.