976results about How to "High grafting rate" patented technology

The invention relates to a preparation method of polar solution-polymerized styrene-butadiene rubber with low gel rate. The method involves grafting polar monomers on solution-polymerized styrene-butadiene rubber by means of free radical solution method, so as to change the polarity and further improve the interface bonding force of styrene-butadiene rubber and carbon black or white carbon black, so that the wet-skid resistance, wear resistance and dynamic mechanical property of vulcanized rubber are improved and the rolling resistance is reduced. The polar monomers used comprise maleic anhydride, acrylic acid, acrylamide, N-vinyl pyrrolidone and the like. The grafting rate of modified styrene-butadiene rubber is 1-5% and the gel rate is 1-3%; and the rubber polarity changes obviously.

The invention discloses a polar monomer graft-modified amorphous poly-alpha-olefin and a preparation method thereof. The polar monomer graft-modified amorphous poly-alpha-olefin is prepared by carrying out grafting reaction on amorphous poly-alpha-olefin, a peroxide initiator, a polar monomer and an auxiliary grafting agent under molten or dissolved conditions. The polar monomer graft-modified amorphous poly-alpha-olefin is prepared from the following raw materials: 100 parts of amorphous poly-alpha-olefin, peroxide initiator accounting for 0.1-1 wt% of the amorphous poly-alpha-olefin, polar monomer accounting for 0.5-10 wt% of the amorphous poly-alpha-olefin, auxiliary grafting agent accounting for 0.1-5 wt% of the amorphous poly-alpha-olefin, solvent accounting for 0-300 wt% of the amorphous poly-alpha-olefin, and antioxidant accounting for 0.05-2 wt% of the amorphous poly-alpha-olefin. The amorphous poly-alpha-olefin has the characteristics of high grafting ratio, light color, high polarity, favorable flowability, favorable storage capability and no risk in moisture crosslinking.

The invention relates to polymer grafted graphene oxide and a preparation method thereof. The method comprises the step that the polymer grafted modified graphene oxide is obtained through an irradiation graft polymerization reaction of C=C contained monomers and graphene oxide under anoxic conditions. The method of the invention, which does not need the modification of graphene oxide or polymers before grafting, has the advantages of simple operation process and wide application range, and is especially suitable for large-scale batch production; and the polymer grafted graphene oxide prepared in the invention has an obviously improved grafting rate, so the polymer grafted graphene oxide can be widely used.

This invention relates to functional nonwoven filter media provided by radiation-induced graft copolymerization and its production method. Meltblown type of nonwoven (Meltblown) comprised of fine fibers, less than 8 micron in diameter, of polyolefin or polyamide is chosen as the suitable grafting trunk polymer. The production methods are composed of following steps, 1) irradiation less than 30 kGy dose to the Meltblown with electron beam or gamma ray; 2) graft copolymerization of emulsified vinyl monomer onto the Meltblown; and 3) chemical conversion of ion exchange group onto the grafted vinyl monomer. These steps are independently conducted in their suitable operation conditions.

The invention relates to the manufacturing field of nano composite emulsion materials, in particular to graft nano zinc oxide/polyacrylate composite emulsion and a manufacturing method thereof. Firstly an initiator azobisisovaleric acid is anchored on the surface of nano zinc oxide particles, two portions of hexadecane are added to 100 portions of mixed monomers, and 5 portions of nano ZnO particles anchoring the azo initiator are added and ultrasonically oscillated for 20 minutes to form an oil phase pre-dispersion solution. The pre-dispersion solution is added to an emulsifier aqueous solution and dispersed by a high-shear dispersion homogenizer at high speed for 30 minutes to form a mini-emulsion. The mini-emulsion is transferred to a reactor, heated to the temperature of 75 DEG C, with polyreaction initiated for 3 hours, and then heated to the temperature of 85 DEG C, polymerized for 2 hours, cooled to room temperature and discharged. The invention solves the problems of high cost and poor stability of the nano composite emulsion prepared by coupling agents, and low encapsulation efficiency and graft ratio of nano polymer composite particles. The composite emulsion has the advantages of simple preparation process, low cost, even particle size, good performance, high encapsulation efficiency and graft ratio of the nano-particles, forms nano monodisperse state in the polymer, and is suitable for the fields of coating materials, leather finishing materials, adhesives and functional plastics.

The invention provides a method for grafting a propylene polymer with a polar monomer. The method comprises a, mixing a propylene polymer, an initiator and an organic solvent to obtain a mixture, b, removing the organic solvent in the mixture obtained by the step a and adding a polar monomer into the mixture for swelling, c, adding water into the swollen material obtained by the step b and heating the solution for a reaction, and d, washing and drying the reaction product obtained by the step c to obtain a propylene polymer grafted with the polar monomer. The method can utilizes an aqueous phase suspension grafting method for the propylene polymer, can observably improve polar monomer grafting efficiency and ratio and is conducive to wide application of the grafting-modified polypropylene.

The invention relates to cranioplasty prosthesis with biological activity and a preparation method of the cranioplasty prosthesis. The cranioplasty prosthesis with biological activity sequentially comprises an unmodified cranioplasty prosthesis layer, a modified cranioplasty prosthesis layer and a nanofiber membrane layer from inside to outside. The invention further provides a preparation method of the cranioplasty prosthesis. By virtue of a three-layer structure and polyaryletherketone materials which are equivalent to a bone of a human body in hardness, strength and weight, are good in biocompatibility, and a 3D printing technology, a cranioplasty prosthesis implant has reliably safety and effectivity and high matching degree. The cranioplasty prosthesis provided by the invention is capable of loading a plurality of bionic scaffolds and bioactive substances, and promoting exchange of nutrient substances inside and outside the prosthesis, and is beneficial to growth of tissues.

The invention discloses a method for preparing a polyvinylidene fluoride affinity membrane using amino acid as a ligand. The affinity membrane is prepared by hydrophilically modifying a polyvinylidene fluoride hollow fiber membrane and grafting the amino acid ligand. The grafting amount of the amino acid is 150 to 250mg/g for each membrane. The invention also discloses application of the affinity membrane in removing endotoxin in blood plasma, which removes the endotoxin in the blood plasma by a dynamic absorption means. The polyvinylidene fluoride affinity membrane prepared by the method has stable performance, good bio-compatibility and high endotoxin removing efficiency, and can be used for whole blood perfusion as well as blood plasma perfusion.

The invention relates to a preparation method for maleic anhydride-grafted polypropylene. The preparation method comprises the following steps: (1) uniformly mixing 0.4 to 2 parts of an initiator and 0.6 to 2 parts of styrene by weight; (2) adding 110 parts of polypropylene and 0.6 to 2 parts of maleic anhydride by weight into a high-speed mixing machine and mixing for 1 to 3 minutes, and meanwhile dropwise adding the product obtained by the step (1); (3) adding the product obtained by the step (2) into a double-screw extruder, blending, extruding, melting and grafting to prepare the maleic anhydride-grafted polypropylene. Compared with the prior art, the preparation method has short reaction time, simple preparation and low production cost, and is suitable for industrialization; an anti-oxidant is not required to be added; the effective reaction time can be prolonged by controlling the factors, such as the rotating speed of a main machine, the feeding rotating speed, the temperature and the like; meanwhile, the maleic anhydride-grafted polypropylene with high grafting rate can be obtained by adding the styrene, so that the grafting efficiency of maleic anhydride is improved; the preparation method does not have special requirements on the double-screw extruder, a liquid feeding device is not required, and the length-diameter selection range is large.

The invention discloses a method for modifying a nano metal oxide by coupling graft, and belongs to the technical field of nano granule surface modification. The nano metal oxide is used as a raw material, N,N'-carbonyl diimidazole (CDI) is used as an activating agent, and a finished product is obtained by simple processes of drying treatment, coupling reaction, separation and purification, coupling graft, re-separation and re-purification. The method has the advantages of simplicity, mild reaction conditions, high grafting efficiency which reaches 87 percent, energy conservation, emission reduction, low cost and suitability for large-scale industrial production. The nano metal oxide prepared by using the method can be widely applied in the fields of rubber, coating, ink, dye, glass, piezoelectric ceramics, photoelectrons, medicament and the like.

The invention provides a method for preparing dopamine-modified hyaluronic acid micelle and belongs to the technical fields of polymer material and natural polymer. The method comprises the steps of introducing dopamine element on a hyaluronic acid main chain by amidation so as to provide certain amphipathy to the hyaluronic acid, so that micelle with the grain size of 100-700nm is formed in water solution by self-assembling. The hyaluronic acid micelle is excellent in biocompatibility, hydrophilicity and viscoelasticity, and can be applied to the fields such as biological materials and hydrophilic colloid. The adhesiveness of the dopamine provides excellent interface property, and the micelle can be applied to the fields such as emulsion, food, cosmetic and the like as emulsifier.

The invention discloses a method for preparing super absorbent resin by the graft copolymerization reaction of carboxymethyl potato starch, acrylamide, acrylic acid and sodium salt thereof, which comprises the following main processes: carrying out neutralization reaction between a sodium hydroxide solution and acrylic acid from which polymerization inhibitor is removed under the cooling of ice-water bath; mixing acrylamide with de-ionized water to obtain an acrylamide solution; mixing the carboxymethyl potato starch with the prepared acrylic acid and the sodium salt solution and the acrylamide solution; adding an evocating agent persulfate and a cross-linking agent N,N'- methylene-bisacrylamide; stirring the mixture under room temperature; heating the mixture by water bath to rise the temperature so as to ensure that the carboxymethyl potato starch, the acrylic acid and the sodium salt thereof and the acrylamide generate graft copolymerization reaction under the protection of nitrogen; keeping the temperature of the reaction; drying and crashing to obtain the super absorbent resin with high potassium content by using carboxymethyl potato starch as the raw material. Compared with the similar products, the water absorption of the super absorbent resin is greatly enhanced; the super absorbent resin contains nitrogen nutrition element, does not need pasting in comparison with theprocess of directly using starch and greatly improves the preparation process. The super absorbent resin has great effect on the water conservation, the desert control, the plant growth promotion andthe like of soil in dry regions.

The present invention relates to a preparation method for organic-inorganic hybrid materials through grafting polymerization-environment responsive macromolecules on the nanometer silicon dioxide surface, belonging to the organic-inorganic hybrid materials synthesis and preparation field. The present invention takes advantage of the action of silicon dioxide with hydroxyl on the surface with the silane coupling agent 3-amino-propyl silane to enable the end to be of an amino group; then the product reacts with the nanometer particle generated from the bromination propionyl bromine reaction; The end of the nanometer particle is the ATRP initiator; finally, the polymerization of the environmentally-responsive macromolecules on the nanometer silicon dioxide surface is initiated in the present of CuBr and PMDETA so as to obtain the target product. The graft rate of the silicon dioxide virgule environmentally-responsive macromolecule core-shell structure nanometer hybrid particles is 60 percent to 70 percent. No reunion of the nanometer hybrid particles appears. The nanometer hybrid particles are uniformly dispersed with environmental responsiveness.

The invention discloses a high temperature resistant modified starch filtration reducing agent and a preparation method thereof. The modified starch filtration reducing agent and the preparation method comprise that: with starch, a phenolic compound, alkenyl amide and alkenyl sulfonic acid as raw materials, an oil phase solution as a continuous phase and a nonionic surfactant as an emulsifying agent, and under catalytic actions of a reduction substrate and a hydrogen acceptor substrate, a starch graft copolymer is generated through a reaction. The filtration reducing agent provided by the invention is resistant to temperature of up to 175 DEG C, and simultaneously also has good salt and calcium resistance capabilities; and the preparation method is simple and easy to implement, and has mild and controllable reaction conditions, high grafting efficiency, fast reaction speed and low cost.

The invention relates to an environment-response intelligent weave fabric and relative preparation. Wherein, adding the fabric which is induced by argon microwave low-temperature plasma to generate free group on surface, into the dual monomer solution of 2-acrylamide-2-methanesulfonic acid and N-isopropyl acrylamide that contains N and N'-methylene dual acrylamide cross linker to process graft polymerization reaction, while the bath ratio is 1:40, to graft the dual intelligent gel on the fiber macromolecule of fabric, to attain said inventive product. When the invention is dry, it has no difference from general fabric, but when it is wet, the gel will adsorb water to expand and block the slits between fibers, to reduce the water and gas permeability of fabric, and avoid outer penetrating into the inner layer of fabric to stop heat emission. The invention can be used to produce army waterproof clothes, heat-accumulation temperature adjustable special clothes, etc.

The invention discloses a preparation method of polylactic acid functionalized graphene, which comprises the steps of preparing graphite oxide by adopting an improved Hummers method; performing ultrasonic peeling and freeze drying to obtain graphene oxide; mixing the graphene oxide with anhydrous lactic acid at certain proportion; adding a catalyst, and performing in-situ polymerization in vacuum environment to obtain a graphene/polylactic acid complex; and washing off the polylactic acid not in covalent binding with graphene to obtain polylactic acid functionalized graphene. The preparation method of polylactic acid functionalized graphene provided by the invention takes graphene oxide as an initiator and grafts polylactic acid to the surface of graphene oxide through lactic acid condensation polymerization by adopting a one-step method. The method does not need to perform pretreatment on graphene; the treatment process of lactic acid condensation polymerization is relatively simple and easy to realize, and the cost is relatively low. Moreover, the surface of graphene oxide is rich in oxygen-containing functional groups such as carboxyl group, hydroxyl group and the like; and relatively high grafting rate can be obtained through simple treatment.

The invention relates to a low temperature impact resistant nylon flexibilizer and a preparation method of the low temperature impact resistant nylon flexibilizer. The low temperature impact resistant nylon flexibilizer comprises the following components in parts by weight: 50-95 parts of ethylene-alpha-octylene copolymer resin, 4-40 parts of polypropylene copolymer, 1-30 parts of linear low density polyethylene, 0.5-10 parts of graft monomer, 0.01-2 parts of initiator, 0.1-1 part of lubricator, 0.1-1 part of antioxidant and 0.1-2 parts of liquid additive. The preparation method of the low temperature impact resistant nylon flexibilizer comprises the steps of: mixing the above components except for the initiator, and adding into a double-screw extruder; laterally feeding and metering the initiator, and adding into the extruder; and extruding and pelletizing to obtain the low temperature impact resistant nylon flexibilizer as a product. The graft ratio of the flexibilizer is increased and the gel content of the flexibilizer is reduced by the lateral feeding technology; after the flexibilizer is applied to nylon (nylon 6, nylon 66), the flexibilizer is good in comprehensive performance and more excellent in low temperature impact performance; and the notch impact strength of the flexibilizer can reach 600J/m at a temperature of -30 DEG C, so that the flexibilizer can be applied to the fields of auto accessories and bumpers, railway equipment and the like under low temperature resistance.

The invention belongs to the field of cellulose modification and utilization and in particular relates to a preparation method of a surface-grafted modified nanocellulose crystal. The preparation method of the surface-grafted modified nanocellulose crystal comprises the following steps of: dispersing nanocellulose crystal in an organic solvent; introducing an unsaturated double bond onto the surface of the nanocellulose crystal through a reaction of maleic anhydride and hydroxyl groups on the surface of the nanocellulose crystal; and introducing an initiator and an unsaturated monomer to prepare the surface-grafted modified nanocellulose crystal through a radical polymerization reaction. The surface-grafted modified nanocellulose crystal is uniformly dispersed in a polymer matrix and good in compatibility with the interface of the polymer matrix, and therefore, the prepared polymer nanometer composite material has higher tensile strength and elongation at break. The preparation method of the surface-grafted modified nanocellulose crystal has the advantages of rich raw material resource, simple process, completely biodegradable product, high mechanical performance and the like, and can be used for a plurality of fields including the packaging field, the biological field, the medical field, the engineering plastic field and the like.

The invention relates to an ultraviolet radiation two-step grafting method on the surface of polyethylene fiber with ultrahigh molecular weight. The method comprises the following steps of: coating a photosencitizer on the surface of preprocessed polyethylene fiber with ultrahigh molecular weight; soaking the polyethylene fiber in a first grafting monomer solution; forming a surface dormant group by adopting ultraviolet radiation or direct illumination; then, soaking in a second grafting monomer solution; initiating a secondary monomer surface free radical grafting reaction by ultraviolet radiation or heating; and finally, post-processing. Compared with the prior art, the invention has the advantages that the polar group is introduced to the surface of the polyethylene fiber with ultrahigh molecular weight, the reaction is controllable, the grafting efficiency and the grafting rate are higher, the second monomer with higher reaction activity is grafted on a primary grafting basis, and the adhesive performance of a matrix and the polyethylene fiber with ultrahigh molecular weight is greatly improved.

The surface modification process of silicon carbide includes: soaking silicon carbide powder in mixed solution of concentrated sulfuric acid and hydrogen peroxide solution; taking out, flushing with deionized water and stoving; reacting with coupling agent for 1-4 hr; setting silicon carbide inside acetone solution for supersonic cleaning and centrifuging for 2-5 times to obtain processed silicon carbide; adding cross-linking agent to acrylic acid aqua and regulating pH to 5-9 with sodium hydroxide, sodium carbonate or sodium bicarbonate; adding initiator to form the polymerizing precursor solution; mixing processed silicon carbide and the polymerizing precursor solution to obtain surface modified silicon carbide. The product has grafting rate of 0.6-16.2 % and water absorbing rate of 3.0-30 g/g.

The invention discloses a maleic anhydride grafted polypropylene material. Maleic anhydride, polypropylene and an assistant grafting monomer are grafted under the effects of an initiator and an antioxidant to obtain the maleic anhydride grafted polypropylene material. The used assistant grafting monomer can play a role of increasing the grafting ratio and inhibiting the polypropylene to be degraded, and therefore the grafting ratio is effectively increased. Meanwhile, a new initiator is introduced to reduce the pungent smell of the maleic anhydride grafted polypropylene material, and the degree of grafting reaction and the degree of copolymerization of the assistant monomer are enhanced, so that the prepared product has a high grafting ratio and low pungent smell.