250 results about "Poly(N-isopropylacrylamide-co-acrylamide)" patented technology

A temperature responsive intelligent face mask and preparation method thereof wherein a chitosan modified temperature sensitive isopropyl acryl amide / polyurethane copolymer hydrogel is grafted to a cellulose fiber. The advantages lie in that the intelligent hydrogel can swell and contract reversibly near body temperature, and the high-temperature dehydration phenomenon may be inhibited by the introduction of the polyurethane, the non-woven fabric exerts a supporter function by grafting the isopropyl acryl amide / polyurethane copolymer hydrogel thereto and as a result the strength of the gel is increased, the coupling of the natural chitosan to external surface of the gel film not only improves the face mask comfort, the skin affinity, but also offers the bacteria resistant ability. The gel face mask carries multiple nutrients and the carried nutrient and moisture may release intelligently through gel contraction under body temperature, meanwhile the temperature responsive intelligent face mask can be utilized in a plurality of times to satisfy the personalized requirement.

The invention relates to a preparation method of a temperature sensitive hydrogel having an obvious shear thickening characteristic which can be controlled through temperature change. The hydrogel adopts poly(N-isopropylacrylamide) crosslinking network as a matrix, a certain concentration of an aqueous solution of polyethylene glycol is swelled in the matrix, and a certain mass fraction of poly(N-isopropylacrylamide) grafted nano-SiO2 microspheres are dispersed in the aqueous solution. The hydrogel has the obvious shear thickening characteristic, the shear thickening effect of the hydrogel can be controlled through temperature, and the hydrogel has obvious temperature sensitivity.

An implantable medical device, perhaps a pacemaker lead, has a medical unit and a casing at least partially enclosing the medical unit. The casing is formed of a base polymer having surface modifying pendant groups formed of an acrylamide polymer or an acrylamide copolymer, perhaps polyisopropyl acrylamide. The base polymer may be a polyurethane, polyimide, fluoropolymer or polyolefin, for example.

The invention relates to an artificial skin alternative material and a preparation method thereof. According to the artificial skin alternative material, a polyurethane material serves as a base layer; a structure layer, which is formed by grafting, copolymerizing and modifying the polyurethane material and poly-N-isopropylacrylamide, is coated on the surface of the base layer; the molar ratio of the poly-N-isopropylacrylamide to the polyurethane material is (0.1-1):1; and the grafting ratio of the poly-N-isopropylacrylamide is 20 to 150 percent of the mass of the polyurethane material. The preparation method comprises the following steps of: performing bulk polymerization or solution polymerization on at least one of polyester polyol or polyether glycol serving as a hydroxyl donor component and an isocyanate component under the catalysis according to the molar ratio of an isocyanate group to the total hydroxyl of the hydroxyl donor of (0.8-1.8):1 to obtain the base layer polyurethane material; and grafting, copolymerizing and modifying the base layer polyurethane material and the poly-N-isopropylacrylamide to obtain the artificial skin. The artificial skin alternative material has an excellent mechanical property close to that of the skin and has certain temperature sensitivity. The artificial skin alternative material can be prepared from the hydroxyl donor component and the isocyanate component. The preparation method is easy and convenient to operate, low in energy consumption, low in cost and suitable for large-scale production.

The invention provides a deformation controllable hydrogel actuator and a preparation method thereof. The deformation controllable hydrogel actuator is prepared from an inorganic nano-material, poly(isopropyl acrylamide) and water, wherein the concentration distribution of the inorganic nano-material in a thickness direction is non-uniform, so as to form an asymmetrical heterojunction structure; in a plane direction, the non-uniform asymmetrical structure can be randomly patterned according to requirements, so that various reversible deformation triggered by temperature is realized. The preparation method comprises the following steps: mixing isopropyl acrylamide monomer, an initiator and the inorganic nano-material to form uniform pre-gel; pouring the pre-gel into a rectangular mold; covering one layer of mask plate on the pre-gel; evaporating partial water to induce the concentration of the inorganic nano-material to be not uniformly distributed in the thickness direction of an exposed region; then carrying out in-situ polymerization to fix a patterned non-uniform structure, so as to form the deformation controllable hydrogel actuator. The method is simple and feasible and easy to realize; the deformation controllable hydrogel actuator can be used for soft robots, drug delivery, microfluidic valves and artificial muscle.

The invention discloses temperature and redox stimuli responsive nano-hydrogel and a preparation method thereof. The nano-hydrogel is named as disulfide crosslinking poly(isopropylacrylamide)-grafted glucan. The preparation process comprises the following steps: synthesizing 2-dodecyltrithiocarbonyl-2-methyl propionate; synthesizing 2-dodecyltrithiocarbonyl-2-methyl propionate-grafted glucan macromolecules; synthesizing poly(isopropylacrylamide)-grafted glucan; and synthesizing disulfide crosslinking poly(isopropylacrylamide)-grafted glucan polymer. The nano-hydrogel and preparation method have the following advantages: the preparation method adopts the reversible addition-fragmentation chain transfer free radical polymerization method; the process is characterized in that the polymerization process is controllable, the used reagents are non-toxic or less toxic to the organism, the obtained product molecular structure is accurate and the molecular weight distribution is controllable; and the prepared temperature and redox stimuli responsive nano-hydrogel has wide applicability.