52results about How to "High shape recovery rate" patented technology

The invention discloses a body-heat-excited polylactic-acid-base biodegradable shape memory material, and a preparation method and application thereof. The material is composed of the main components polylactic acid and thermoplastic elastomer in a mass ratio of (70-90):(30-10), and also composed of 10-40 phr of plasticizer. The preparation method comprises the following steps: mechanically mixing the main components into a premix, adding into an extruder, and carrying out melt blending to obtain the shape memory material. The shape memory material is used for manufacturing fixers for medical treatment. The shape recovery temperature of the polylactic-acid-base biodegradable shape memory material can be adjusted to near body temperature, thereby implementing the body-heat-excited effect. The shape memory material can be better applied to biological medical materials to greatly enhance the market competitiveness of the product.

The invention relates to high-deformation thermosetting shape memory resin based on bismaleimide and a preparation method thereof. The method includes the following steps that the bismaleimide and 1,6-ethanthiol are added into m-cresol to form a solution; triethylamine is added into the solution dropwisely, and under the protection of N2 and a stirring condition, a reaction is carried out at roomtemperature to obtain a linear oligomer; the bismaleimide, the linear oligomer and O,O'-diallylbisphenol A are mixed by mass, and the reaction is carried out at 130-150 DEG C for 25-45 min to obtain aprepolymer; the prepolymer is subjected to vacuum defoamation at the temperature of 130-150 DEG C, and through solidification and post-treatment, the thermosetting shape memory resin based on the bismaleimide is obtained. Compared with the prior art, the resin has a high deformation capability, and the breaking elongation of the resin at programming temperatures is higher than 30%; moreover, thethermosetting resin has both high glass-transition temperature (larger than 131 DEG C) and initial decomposition temperature (larger than 370 DEG C), high tenacity and outstanding shape memory performance.

The invention relates to a method for preparing a star-shaped biodegradable shape-memory-polymer nano composite material. According to the shape-memory composite material, POSS and isocyanate chain segments are taken as a hard phase, and poly-D,L-lactide and polytetramethylene ether glycol are taken as a soft phase. The method for preparing the shape-memory composite material comprises the steps of firstly preparing polyhedral silsesquioxane, of which eight vertexes are provided with hydroxyl groups, initiating the ring-opening polymerization of D,L-lactide with polyhedral silsesquioxane so as to prepare star-shaped POSS-PLA of a certain molecular weight, and then, coupling to polytetramethylene ether glycol through diisocyanate, thereby forming a three-dimensional reticulated copolymer. The shape-memory composite material prepared by the method has the characteristics of strong deformation holding ability, high shape recovery rate, good shape memory performance and repeatability, biodegradation and the like; furthermore, due to the adding of inorganic nanoparticle POSS, the recovery stress of a shape memory polymer is increased.

The invention discloses a shape memory polymer alloy for fused deposition based 3D printing and a preparation method of the shape memory polymer alloy. The polymer alloy is prepared from raw materialsin percentage by weight as follows: 30%-50% of polyolefin plastics, 10%-40% of nylon resin, 20%-40% of thermoplastic elastomer graft, 0.1%-1% of a peroxide crosslinking agent, 0-5% of an assistant crosslinking agent and 1%-5% of a nanofiller. The raw materials mixed by a high-speed mixer are subjected to melt extrusion molding, and the polymer alloy suitable for fused deposition based 3D printingcan be obtained. The prepared polymer alloy has excellent 3D printing performance, so that a printed product has the characteristics of being low in warping degree, high in dimensional stability, better in mechanical property and heat resistance and the like and has a smooth surface without defects and an excellent thermally induced shape memory function, and the printed product are higher in shape fixed rate and shape recovery rate, and the application requirement of a shape memory product can be met.

The invention relates to a deformable aerogel material and a preparation method thereof. The method comprises the steps of carrying out a polycondensation reaction using a diamine and a dianhydride asmonomers, and then adding 1,1,1-tri[4-(aminophenoxyl)phenyl]ethane as a curing agent to obtain a polyamic acid solution, and adding fumed silica nanoparticles to obtain that polyamic acid solution doped with fumed silica nanoparticles, and then treating the polyamic acid solution in a vacuum oven and subjecting to thermal imidization at different temperature stages heating procedures to obtain apolyimide wet gel; subjecting the polyimide wet gel to ageing, solvent replacement and supercritical drying to obtain the deformable aerogel material. The aerogel material of the invention can be deformed and fixed under the heating condition, and the shape is restored under the next thermal response, and the temperature resistance of the material is good. The aerogel material of the invention hasthe advantages of high porosity (88-99%), high shape recovery rate (90-100%), adjustable deformation and recovery temperature and the like.

The invention discloses a multifunctional polysiloxane thermoplastic elastomer as well as a preparation method and application thereof. The elastomer is prepared by the following method: taking 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and octamethylcyclotetrasiloxane as raw materials, and carrying out a reaction under the action of a catalyst tetramethylammonium hydroxide pentahydrate,so as to obtain double amino-terminated polysiloxane; with double amino-terminated polysiloxane, 3,3',4,4'-biphenyl tetracarboxylic dianhydride and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane as raw materials, and carrying out a reaction to obtain a polysiloxane-polyamic acid segmented copolymer; and finally, under the action of high temperature, obtaining the polysiloxane-polyimide block polymer with high mechanical properties, a shape memory function and a self-healing function.

The invention relates to a method for preparing a magneto type biodegradable shape-memory composite material. According to the shape-memory composite material, isocyanate chain segments are taken as a hard phase, and poly-D,L-lactide and polytetramethylene ether glycol are taken as a soft phase. The method for preparing the shape-memory composite material comprises the steps: initiating the ring-opening polymerization of D,L-lactide with micromolecular glycol, so as to prepare poly-D,L-lactide of a certain molecular weight, of which the two terminals are provided with hydroxyl groups, and then, coupling to polytetramethylene ether glycol through diisocyanate, so as to form a straight-chain block copolymer; then, mixing with surface modified Fe3O4 nanoparticles, thereby preparing the magneto type biodegradable shape-memory composite material. The shape-memory composite material prepared by the method has the characteristics of strong deformation holding ability, high shape recovery rate, good shape memory performance and repeatability, biodegradation and the like; furthermore, the function of initiating shape memory in a non-contact manner is realized, and the material can have a targeting property due to the presence of the Fe3O4 nanoparticles.

The present invention discloses a preparation method of a shape memory material capable of physically self-repairing superhydrophobic property. The preparation method comprises: 1, preparing a template, wherein a layer of a porous metal is electroplated on the surface of a metal sheet as a material micro-morphology template; and 2, preparing an epoxy resin material having microtopography, wherein an epoxy resin curing system is prepared, a toughening agent is added to the system, the prepared epoxy resin system and the template are placed into a metal mold to cure, and the hydrogen bubble template is removed after curing so as to obtain the epoxy resin material having micro-morphology. According to the present invention, the material prepared by using the preparation method can repair the disappeared superhydrophobic property caused by material micro-morphology deformation due to physical damage, and the method is simple and is easy to perform, and can be provided for substantially increasing the service life of the superhydrophobic material and enhance the durability of the material.

The invention relates to a shape self-repairing wave-absorbing material and a preparation method thereof. The method comprises the following steps: (1) uniformly mixing a resin matrix, a toughening agent and a curing agent of which a mass ratio is 1:(0.02-0.33):(0.01-0.017), to obtain a resin prepolymer, wherein the resin matrix is selected from a group formed by epoxy resin, polyurethane resin, polystyrene resin and polynorbornene resin; (2) adding an absorbent selected from a group formed by ferrite powder, carbonyl iron powder, conducive carbon black, carbon fibers, silico carbide fibers, carbon nano tubes and graphene to the obtained resin prepolymer, and uniformly stirring, to obtain shape self-repairing wave-absorbing resin; and (3) curing the shape self-repairing wave-absorbing resin in more than two different temperature stages, preparing the shape self-repairing wave-absorbing material. The wave-absorbing material is endowed with shape self-repairing performance through the method, and a requirement of wave-absorbing performance recovery can be satisfied after the wave-absorbing material is damaged to be deformed by an external force.

The invention belongs to the technical field of automobile materials, and provides an EVA (Ethylene-Vinyl Acetate) modified PU (Polyurethane) shape memory vehicle bumper and a preparation method thereof. The preparation method is characterized in that when polyether polyol and isocyanate are used as raw materials for carrying out chemical polymerization to prepare PU, the polyether polyol and isocyanate together with EPDM (Ethylene Propylene Diene Monomer) rubber and EVA are subjected to hot mixing and are commonly injected into a mold for placing a metal framework, and carrying out irradiation crosslinking during a curing process after taking out a product, thus obtaining the EVA modified PU shape memory vehicle bumper. Compared with a traditional method, the EVA modified PU shape memoryvehicle bumper prepared through the preparation method disclosed by the invention has the advantages that a shape memory function is given to a vehicle bumper through modification of EVA resin, the shape recovery rate is high, the shape memory property is excellent, excellent impact resistance, good elasticity and good safety are obtained, external impact force can be effectively absorbed and buffered, a vehicle body can be protected, and the vehicle driving safety can be remarkably increased.

The objective of the present invention is to provide a biodegradable material that has improved flexibility and increased percentage of shape recovery after the material has been deformed. The present invention provides a biodegradable material resulting from a polyvalent compound (A) having at least three functional groups (X) such as hydroxyl groups and a polyvalent compound (B) having at least three functional groups (Y) such as carboxyl groups being chemically crosslinked by means of a condensation reaction, and when the number of functional groups (X) that are not condensed to functional groups (Y) is x, the number of functional groups (Y) that are not condensed to functional groups (X) is y, the number of chemical crosslinks is z, the weight average molecular weight of polyvalent compound (A) is MA, and the weight average molecular weight of polyvalent compound (B) is MB, when MA >= MB, the value of (y+z)/(x+z) is 1.2-4.0, and when MA < MB, the value of (x+z)/(y+z) is 1.2-4.0.

The invention discloses a thermoplastic composition and a preparing method thereof.The thermoplastic composition comprises, by weight, 60-90 parts of epoxidation polyethylene-vinyl acetate, 10-40 parts of thermoplastic polymers and 0.1-20 parts of cross-linking agent.The preparing method of the thermoplastic composition can be achieved on a traditional high-polymer-material processing device, cost is low, the environment is friendly, and industrial production is easy to achieve.The thermoplastic composition obtained with the provided preparing method has the advantages of being high in shape recovery rate and strength, large in elongation at break, excellent in thermoplastic performance and the like, and can be directly used for extrusion molding, compression molding and the like to be used for preparing various thermoplastic and rubber products.

The invention provides a preparation method of shape memory aerogel, which comprises the following steps: step a) in a non-alcohol organic solvent, under anaerobic and stirring conditions, carrying out a first reaction on a sulfydryl reagent and an olefin reagent under the action of a benzoyl polymerization catalyst; step b), carrying out a second reaction on the reaction mixture obtained in the step a) under the action of aromatic tertiary amine under oxygen-free and stirring conditions; c) carrying out a third reaction on the reaction mixture obtained in the step b) under the action of water and a phase transfer catalyst, and carrying out aging and solvent replacement on the obtained reaction mixture to obtain gel; and d) carrying out carbon dioxide supercritical drying on the gel obtained in the step c). The method provided by the invention is simple in process, high in controllable degree, high in accuracy and simple and convenient to operate, and the obtained shape memory aerogel has the characteristics of high porosity, low density, high shape recovery rate, glass-transition temperature range of-60 to 180 DEG C and the like.