A block copolymer consists mainly of structural units each derived from an ethylenically unsaturated monomer and has at least one mercapto group. The block copolymer has an Mn of 5,000-500,000 and has a block structure, which is an A-B-A triblock structure or a star-shaped block structure of [A-B]qX. The q is an integer of 2-6. The polymer block (A) has a glass transition temperature of 20° C. or higher. The polymer block (B) of the triblock structure has a glass transition temperature lower than 20° C., and the [polymer block (B)]qX of the star-shaped block structure has a glass transition temperature lower than 20° C. The X is an initiator residue or/and a coupling-agent residue or is a derivative thereof.

A chloroprene-based block copolymer latex, including a chloroprene-based block copolymer, wherein: the chloroprene-based block copolymer contains 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B); the polymer block (A) is derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; the chloroprene-based polymer block (B) includes a chloroprene monomer unit; and when the chloroprene-based block copolymer latex is molded by immersion molding to obtain a film and then the film is heat-treated at 130° C. for 30 minutes, a tensile strength at break measured in accordance with JIS K6251 of the film is 17 MPa or more is provided.

The invention relates to the technical field of oil and gas drilling, and discloses an amphiphilic block polymer ultralow-permeability agent and an intelligent temporary plugging type water-based drilling fluid. The ultralow-permeability agent contains a structural unit provided by styryl hydrophobic monomer, maleic anhydride and acrylamide; the drilling fluid contains two or more of water, sodium bentonite, Pac-Lv, the ultralow-permeability agent, calcium carbonate, one-way plugging agent, white asphalt and barite which are stored in a mixed manner or independently stored. When the amphiphilic block polymer provided by the invention is used as the ultralow-permeability agent of the intelligent temporary plugging type water-based drilling fluid, the self-adaptive characteristic is realized; according to the amphiphilic block polymer, temporary plugging layer gaps formed in pore and throats by plugging materials in drilling fluid can be fully filled under the condition that the sizes and the distribution of the pore and throats of reservoirs are not required to be clear, so that the permeability of temporary plugging layer is greatly reduced, ultralow-permeability is realized, and the amphiphilic block polymer is weak in tackifying effect, has gel-improving effect and can improve the rheological property of the drilling fluid.

Disclosed herein is a composite material comprising a substrate coated with a block copolymer brush, where the block copolymer brush comprises a first block of a hydrophobic polymer conjugated to a nitric oxide source, where the first block of the hydrophobic polymer is covalently bonded to a surface of the substrate or a first block of a cationic polymer covalently bonded to a surface of the substrate and a second block of a hydrophilic polymer, extending from the first block to form an outer surface of the block copolymer brush.

Provided is a block copolymer with an acid group that, when used as a dispersant, can provide a dispersion composition having excellent dispersion stability, a dispersant containing the block copolymer, and a pigment dispersion composition using the dispersant. The block copolymer is an ABA block copolymer including an A block and a B block and has the feature that its acid value is 30 to 250 mgKOH/g and the B block contains a structural unit derived from a vinyl monomer with an acid group.

A composition comprises: a base oil; an additive comprising a copolymer comprising hydrophobic and hydrophilic units; and a drug. The copolymer may for example have a comb structure in which the hydrophobic units and hydrophilic units are pendant chains on a backbone of the copolymer. The hydrophobic units and hydrophilic units may for example comprise polydimethylsiloxane moieties and ethylene glycol residues respectively. The composition may for example be used as a tamponade or as a component for a tamponade administered to the eye. The invention is useful for solubilising and/or releasing drugs.

The present invention provides polymers and methods of preparing the same. In certain embodiments, the polymers comprise acrylate repeating units that have been derivatized (e.g., reduced and/or substituted) to form new polymeric structures. In certain embodiments, the polymers described herein self-assemble to form well-defined nanostructures. In some instances, the nanostructures exhibit relatively small d-spacing (e.g., a d-spacing value of 10 nm or less). Due to their properties, the polymers described herein are useful in a variety of applications including functional materials and biomedical applications.

The present invention provides polymers and methods of preparing the same. In certain embodiments, the polymers comprise acrylate repeating units that have been derivatized (e.g., reduced and/or substituted) to form new polymeric structures. In certain embodiments, the polymers described herein self-assemble to form well-defined nanostructures. In some instances, the nanostructures exhibit relatively small d-spacing (e.g., a d-spacing value of 10 nm or less). Due to their properties, the polymers described herein are useful in a variety of applications including functional materials and biomedical applications.

Provided herein are micellic assemblies comprising a plurality of copolymers. In certain instauces, micellic assemblies provided herein are pH sensitive particles.

The present application relates to brush amphiphilic block copolymers comprising at least one block which is hydrophilic and at least another block which is hydrophobic. The block copolymers can be used to prepare nanoparticles for biomedical applications including delivery of pharmaceuticals and other bioactive agents