A novel graft polymer can include a block copolymer backbone (A) as a graft base having polymeric sidechains (B) grafted thereon. The polymeric sidechains (B) are obtainable by polymerization of at least one vinyl ester monomer (B1) and optionally N-vinylpyrrolidone as optional further monomer (B2). For example, the block copolymer backbone (A) is a triblock copolymer of polyethylene oxide (PEG) and polypropylene oxide (PPG). Also included is a process for obtaining such a graft polymer, the process is preferably carried out by free-radical polymerization.

A double-sided pressure-sensitive adhesive includes an acrylic pressure-sensitive adhesive, wherein the acrylic pressure-sensitive adhesive is formed from an acrylic pressure-sensitive adhesive composition, wherein the acrylic pressure-sensitive adhesive composition contains an acrylic partially polymerized product obtained by polymerizing a monomer component (m1), a monomer component (m2), a cross-linking agent, and a photopolymerization initiator, wherein the monomer component (m2) contains an alkyl (meth)acrylate having, at an ester terminal thereof, an alkyl group having 4 to 10 carbon atoms, and a polymerizable monomer whose corresponding homopolymer has a Tg of 0° C. or more, and wherein in the monomer component (m2), a content of the polymerizable monomer whose corresponding homopolymer has a Tg of 0° C. or more is from 10 parts by weight to 90 parts by weight with respect to 100 parts by weight of the alkyl (meth)acrylate having, at an ester terminal thereof, an alkyl group having 4 to 10 carbon atoms.

A double-sided pressure-sensitive adhesive includes an acrylic pressure-sensitive adhesive, wherein the acrylic pressure-sensitive adhesive is formed from an acrylic pressure-sensitive adhesive composition, wherein the acrylic pressure-sensitive adhesive composition contains an acrylic partially polymerized product obtained by polymerizing a monomer component (m1), a monomer component (m2), a cross-linking agent, and a photopolymerization initiator, wherein the monomer component (m2) contains an alkyl (meth)acrylate having, at an ester terminal thereof, an alkyl group having 4 to 10 carbon atoms, and a polymerizable monomer whose corresponding homopolymer has a Tg of 0° C. or more, and wherein in the monomer component (m2), a content of the polymerizable monomer whose corresponding homopolymer has a Tg of 0° C. or more is from 10 parts by weight to 90 parts by weight with respect to 100 parts by weight of the alkyl (meth)acrylate having, at an ester terminal thereof, an alkyl group having 4 to 10 carbon atoms.

Disclosed are a heat-expandable polyvinylidene chloride microsphere and its preparation method. The preparation method comprises: by weight, dissolving 250 to 550 parts of an aqueous-phase polymerization inhibitor, 20 to 100 parts of a dispersant, and 3 to 15 parts of a co-dispersing monomer in deionized water, adjusting a pH value of the solution and cooling the solution to obtain an aqueous phase for later use; dissolving 5 to 15 parts of a cross-linking agent and 20 to 45 parts of an initiator in 1000 to 2000 parts of a mixed monomer, and cooling the solution to obtain an oil phase for later use; mixing and homogenizing the aqueous phase and the oil phase with stirring to obtain a homogenized mixed solution; adding 300 to 550 parts of a foaming agent to the homogenized mixed solution and homogenizing the resulting solution with stirring to obtain a homogenized mixed solution containing the foaming agent; reacting the homogenized mixed solution containing the foaming agent with stirring; at the end of the reaction, cooling to room temperature, filtering the resulting suspension to obtain filtrate, centrifuging and dehydrating the filtrate, and drying to obtain the heat-expandable polyvinylidene chloride microsphere product. This disclosure has the advantages of simple process and environmental friendliness, and the obtained product has good performance.

Disclosed are a heat-expandable polyvinylidene chloride microsphere and its preparation method. The preparation method comprises: by weight, dissolving 250 to 550 parts of an aqueous-phase polymerization inhibitor, 20 to 100 parts of a dispersant, and 3 to 15 parts of a co-dispersing monomer in deionized water, adjusting a pH value of the solution and cooling the solution to obtain an aqueous phase for later use; dissolving 5 to 15 parts of a cross-linking agent and 20 to 45 parts of an initiator in 1000 to 2000 parts of a mixed monomer, and cooling the solution to obtain an oil phase for later use; mixing and homogenizing the aqueous phase and the oil phase with stirring to obtain a homogenized mixed solution; adding 300 to 550 parts of a foaming agent to the homogenized mixed solution and homogenizing the resulting solution with stirring to obtain a homogenized mixed solution containing the foaming agent; reacting the homogenized mixed solution containing the foaming agent with stirring; at the end of the reaction, cooling to room temperature, filtering the resulting suspension to obtain filtrate, centrifuging and dehydrating the filtrate, and drying to obtain the heat-expandable polyvinylidene chloride microsphere product. This disclosure has the advantages of simple process and environmental friendliness, and the obtained product has good performance.

Provided herein are antioxidant, thermally-responsive copolymer-based compositions and methods of making and using the compositions, e.g., for treatment of ischemia reperfusion injury in a patient. The copolymer comprises a hydrocarbyl backbone, and a plurality of pendant pyrrolidone, antioxidant radical, polyester oligomer, and N-alkyl amide groups.

Provided herein are antioxidant, thermally-responsive copolymer-based compositions and methods of making and using the compositions, e.g., for treatment of ischemia reperfusion injury in a patient. The copolymer comprises a hydrocarbyl backbone, and a plurality of pendant pyrrolidone, antioxidant radical, polyester oligomer, and N-alkyl amide groups.

A method of preparing PNVCL block polymers as the substrate for thermo-sensitive cultureware is provided. A hydrophobic polymer of poly n-butyl mathacrylate (PBMA) is obtained by atom transfer radical polymerization (ATRP) with typical haloalkane as an initiator. Further a thermo-sensitive block copolymer of poly n-vinyl caprolactam (PNVCL) is obtained by polymerization of N-vinyl caprolactam (NVCL) monomers using the hydrophobic PBMA polymer as a macroinitiator.

A method of preparing PNVCL block polymers as the substrate for thermo-sensitive cultureware is provided. A hydrophobic polymer of poly n-butyl mathacrylate (PBMA) is obtained by atom transfer radical polymerization (ATRP) with typical haloalkane as an initiator. Further a thermo-sensitive block copolymer of poly n-vinyl caprolactam (PNVCL) is obtained by polymerization of N-vinyl caprolactam (NVCL) monomers using the hydrophobic PBMA polymer as a macroinitiator.

The present invention generally relates to the composition of particle gels for conformance control, well drilling and well treatments. More particularly, this invention relates to swellable polymer particle gels that can re-crosslink, i.e., reassociate and self-heal, at subterranean conditions. These particle gels can be deployed to improve the conformance of water flooding of especially matrix bypass events (MBEs), that are also known as void space conduits. Moreover, these particle gels can be deployed for controlling the water production and increasing of petroleum recovery. The inventive particles can also be deployed as diverter for well stimulation.