869 results about "Melt blending" patented technology

The present invention discloses a water-based emulsion of PHA, PBAT and PVOH and its application in paper-based barrier coatings. This emulsion is prepared by first melt-blending PHA and PBAT at 150-170 °C and then dispersing them into an aqueous PVOH solution at 80-95 °C. Plasticizers, cross-linking agents and surfactants can be added to improve the performance. After coating on paper and drying at 80-150 °C, a barrier film with a Cobb value of 10-15 g / m² and a Kit ≥ 10 grade is formed. Compared with traditional PE film laminating or fluorine-containing coatings, this system is more environmentally friendly and recyclable; PVOH dissolves in pulping water, PHA and PBAT are easily separated, and fibers can be efficiently recovered; in composting, soil and marine environments, PHA and PBAT have extensive biodegradability and are superior to PLA which is difficult to recycle and requires industrial composting. It is applicable to food, industrial, special packaging and agricultural paper products.

The invention discloses a method for preparing a modified PHA composite material by using a twin-screw extruder and application of the modified PHA composite material. The method comprises the following steps: carrying out in-situ melt blending on polyhydroxyalkanoate (PHA), poly (butylene adipate terephthalate)-poly (butylene adipate terephthalate) (PBAT), polyvinyl alcohol (PVOH) and chain extenders in a twin-screw extruder, so that the chain extenders such as polyfunctional group epoxy or isocyanate react with molecular terminal groups of the PHA, the PBAT and the PVOH to form a partially crosslinked or grafted structure; therefore, the compatibility is enhanced, the thermal stability is improved, and the barrier property is remarkably improved. Experiments prove that the obtained modified PHA composite material has the characteristics of high strength, high elongation, excellent water and oxygen resistance and biodegradability, and meets the strict requirements of multiple fields such as food packaging, agricultural plastic mulching films, medical consumables and the like on mechanical properties and barrier properties. The preparation method is simple, convenient and efficient, and large-scale continuous production can be achieved on existing double-screw extrusion equipment.

The invention relates to an antistatic MLCC release film base film and a preparation method thereof. The antistatic MLCC release film base film is prepared by melt blending and biaxial stretching of PET master batch, an antistatic composition and a nano filler, wherein the antistatic composition is prepared by compounding modified PET-PEG and thiophene modified aromatic polyamide; the nano filler is prepared by carrying out melt extrusion on KH550 modified talcum powder and MAH-g-PET (maleic anhydride-grafted polyethylene terephthalate). The antistatic composition disclosed by the invention has the beneficial effects that the antistatic composition is formed by interweaving two polymers, and a stable three-dimensional conductive network is constructed in the PET film, so that the antistatic performance is more efficient, lasting and stable. In addition, through chemically bonded modified talcum powder, the smoothness and low roughness are provided, and meanwhile reinforcing and toughening are achieved; and the single-layer extrusion process can realize ultrathin thin film, the production process is simplified, and the production cost is greatly reduced.

The invention provides a method for optimizing the mechanical property of a bio-based composite material based on nano modification, and belongs to the technical field of high-molecular compound compounds.The method includes the steps that wood flour is subjected to silane coupling agent modification pretreatment, a functionalized nano particle dispersion liquid is prepared, the dispersity is evaluated through a graph theory model, and the mechanical property of the bio-based composite material is optimized. The modified wood flour and polyethylene are subjected to melt blending in a twin-screw extruder in proportion, the functionalized nanoparticle dispersion liquid is synchronously added, real-time regulation and control are performed by using an intelligent dispersion optimization model, and the network structure integrity is evaluated through gridding performance indexes. The tensile strength, the bending strength and the impact strength are comprehensively optimized by adopting a multi-objective optimization game model, the process parameters such as the nano-particle addition amount, the mixing temperature and the mixing time are adjusted according to the optimization result, and the optimization is repeated until the preset target values are reached, so that the problems that the nano-particles are non-uniformly dispersed, local stress concentration points are formed, and the stability of the nano-particles is improved are solved. The overall mechanical property is influenced.

The invention discloses a plastic hollow plate and a manufacturing method thereof, the plastic hollow plate comprises the following components by weight: 30%-60% of a polypropylene matrix and 40%-70% of phosphogypsum powder, and polypropylene provides thermoplastic formability and toughness. The preparation method specifically comprises the following steps: 1) pretreating ardealite; 2) melt blending granulation; (3) forming a hollow plate; and 4) post-processing. The ardealite hollow plate has the advantages that the ardealite filling amount is increased, meanwhile, the bending strength and impact strength of a traditional hollow plate are improved, and the performance is improved by 20% or above compared with that of a traditional hollow plate with the same filling amount; the moisture content of the pretreated phosphogypsum is less than 6%, so that bubbles in the processing process are avoided, and the interface bonding strength is improved; the comprehensive utilization rate of industrial byproduct phosphogypsum is improved, and the production cost is reduced.

The invention relates to the technical field of polypropylene materials, in particular to a polypropylene material for logistics turnover and a preparation process thereof. The polypropylene material for logistics turnover is prepared from the following components in parts by weight: 80 to 100 parts of polypropylene, 10 to 15 parts of modified nano zinc oxide, 5 to 10 parts of talcum powder, 3 to 5 parts of nucleating agent, 0.5 to 1.5 parts of lubricant, 0.5 to 1.0 part of antioxidant and 0.5 to 1.0 part of stabilizer. The preparation method comprises the following steps: S1, uniformly stirring polypropylene, modified nano zinc oxide, talcum powder, a nucleating agent, a lubricant, an antioxidant and a stabilizer to obtain a mixture; s2, adding the mixture into a twin-screw extruder for melt blending, extrusion and foaming to obtain the polypropylene material for logistics turnover, which not only has excellent mechanical properties, but also has excellent antibacterial properties and aging resistance.

The invention discloses a silane cross-linked polyolefin halogen-free flame-retardant cable material and a low-energy-consumption preparation method thereof.The preparation method comprises the steps that EVA / EEA serves as a matrix, silane groups are covalently connected to a polyolefin molecular chain through a free radical grafting reaction, and a grafting material containing an active silane side group is prepared; meanwhile, vinyl isocyanate is adopted to chemically modify hydroxyl on the surface of magnesium hydroxide, vinyl is grafted to the surfaces of particles, the polarity of the particles is reduced, and the dispersity of the particles is enhanced; then carrying out melt blending on the grafted material and modified magnesium hydroxide, constructing an interface bridge by using an anhydride group, and shortening the two-phase distance; finally, through room-temperature natural cross-linking and warm water auxiliary cross-linking, silane groups are promoted to be hydrolyzed into silanol, the silanol is condensed to form a-Si-O-Si-three-dimensional network, meanwhile, vinyl on the surface of magnesium hydroxide and a polyolefin matrix are subjected to free radical copolymerization, and a covalent bond interface layer is formed between inorganic particles and an organic matrix. According to the method, the synergistic improvement of high crosslinking degree, strong stretchability and excellent flame retardance of the cable material is realized through molecular-level interface regulation and cross-linking network optimization.

The invention relates to a composite solid electrolyte and a preparation method and application thereof. The preparation method of the composite solid electrolyte comprises the following steps: S1, mixing an inorganic filler and a fluorine-containing compound, and reacting at 70-90 DEG C under an acidic condition to obtain an inorganic filler wrapped by a fluorinated layer; then adding a fluorine ion complexing agent and a silane coupling agent for reaction to obtain a modified filler; adding a thermal decomposition type cross-linking agent into the polymer, and carrying out melt blending to obtain a cross-linked polymer; s2, uniformly mixing the modified filler, a cross-linked polymer, a lithium salt and a solvent to obtain a plurality of slurries containing the modified filler with different volume concentrations; and molding the slurry to prepare the composite solid electrolyte. According to the method, the fluorinated layer and the siloxane network are constructed step by step, so that the interface impedance is reduced, and efficient dissociation of the lithium salt is promoted; a three-dimensional network structure is combined, so that the tensile strength is improved; the modified filler is further designed in a gradient manner to improve the lithium ion transference number.

The invention relates to the technical field of cable sheath materials, and provides a high-speed locomotive cable super-cold-resistant sheath material and a preparation method thereof, and the super-cold-resistant sheath material comprises the following raw material components by mass: 60-80 parts of a matrix polymer; 5 to 15 parts of a toughening agent; 3-10 parts of a cold-resistant auxiliary agent; 10 to 20 parts of a flame retardant; 1-5 parts of an antioxidant; 3-10 parts of a nano modified filler; and 1-5 parts of a cross-linking agent. The preparation method comprises the following steps: selecting the raw materials according to the proportion, putting the raw materials into mixing equipment, uniformly mixing to form a primary mixture, and preparing the primary mixture into the composite material through a melt blending process under specific temperature and shearing conditions. The obtained composite material is processed through an extrusion molding process to obtain a sheath material with excellent flexibility, impact resistance and aging resistance, and the problem that an existing material still has embrittlement, cracking or performance reduction in an extremely cold environment is solved.

The utility model discloses a melt blending extrusion device which comprises a mixing tank and an extrusion assembly, and the extrusion assembly is arranged below the mixing tank; a stirring shaft is arranged in the mixing tank, the first stirring spiral blade is arranged on the stirring shaft, a plurality of rotating shafts are movably connected with the lower part of the stirring shaft in the mixing tank at equal angles, and second stirring spiral blades are arranged on the rotating shafts. In conclusion, the material mixing device overcomes the defects in the prior art, is reasonable in design, can push materials in the middle of the material mixing tank downwards and diffuse the materials outwards, avoids precipitation or layering of the materials in the mixing process, improves the mixing effect, and has high social use value and application prospects.

The invention discloses a rare earth hybrid flame retardant as well as a preparation method and application thereof, and belongs to the technical fields of inorganic synthesis, flame retardants and high polymer materials. Rare earth hydroxide is successfully loaded on the surface of a flame retardant through an in-situ deposition method to prepare a rare earth hybrid flame retardant, and the rare earth hybrid flame retardant is further dispersed in a high polymer material matrix through melt blending to prepare the flame-retardant high polymer composite material. The hybrid flame retardant prepared by a deposition method can significantly improve the dispersion compatibility of the flame retardant in a high polymer material, and effectively alleviates the mechanical property degradation caused by the filling of the traditional flame retardant; based on the gas phase-condensation phase synergistic effect of the rare earth hydroxide and the flame retardant, the flame retardance and smoke suppression performance of the high polymer material can be synchronously improved. The rare earth hybrid flame retardant can be applied to various high polymer materials such as polyolefin cables, thermoplastic elastomers, polyurethane and the like, can synchronously improve flame retardance, smoke suppression, mechanical performance and comprehensive performance, and has a wide application prospect.

The invention discloses a high-strength modified high-density polyethylene double-wall corrugated pipe and a preparation method thereof, and relates to the technical field of high-density polyethylene double-wall corrugated pipes. The high-strength modified high-density polyethylene double-wall corrugated pipe is prepared from the following components: high-density polyethylene, ultra-high molecular weight polyethylene, reinforcing filler, a compatilizer, an antioxidant and a lubricant. The preparation method comprises the following steps: reinforcing filler surface modification; all the components are subjected to melt blending to prepare the modified composite material; the modified composite material is subjected to extrusion molding to form the double-wall corrugated pipe; and cooling, shaping and cutting. The UHMWPE and the reinforcing filler are introduced, and the compatilizer is combined to improve interface bonding, so that macromolecular chains of the UHMWPE are entangled to form a tough network, the reinforcing filler provides rigid support, and the high-temperature modulus and creep resistance are synergistically improved; high-temperature oxidative degradation is effectively inhibited through the antioxidant, the slow crack growth resistance time is prolonged, and the service life is prolonged.

The invention relates to the technical field of high-performance polyester fibers, particularly belongs to the patent classification number D01F6 / 00, and discloses a high-moisture-permeability polyester fiber and a preparation method thereof. Comprising the following steps: carrying out hydrothermal reaction on magnesium nitrate hexahydrate and aluminum nitrate nonahydrate to prepare layered double hydroxide nanosheets; then, sodium alginate is prepared into a solution, and the solution is cross-linked with calcium chloride to obtain alginic acid aerogel powder; then, carrying out ultrasonic oscillation dispersion on the two substances in deionized water, and cooling and drying to obtain composite aerogel; then, the composite aerogel and polyethylene glycol 4000 are subjected to melt blending and granulation in a double-screw extruder, and functional master batches are obtained; and finally, mixing the functional master batch with polyethylene glycol terephthalate slices, performing melt spinning at a specific spinning temperature and speed, and performing cooling forming and drafting to obtain the high-moisture-permeability polyester fiber. According to the method, through material compounding and process control, the moisture permeability of the polyester fiber is effectively improved, and the method has a good application prospect in the textile field.

The invention relates to the field of high polymer materials, and discloses a high-wear-resistance elastomer sole material and a preparation method thereof.The material comprises an elastomer matrix and surface-modified boron nitride nanosheets; the elastomer matrix comprises a first dynamic network and a second dynamic network which are formed through crosslinking of dynamic covalent bonds, and the first dynamic network and the second dynamic network are based on different types of dynamic covalent bonds and have different dissociation activation energy barriers or external stimulus response conditions. The surface-modified boron nitride nanosheet and the second dynamic network form a selective interface enhancement effect; the preparation method comprises the steps of polymer functionalization, nanosheet surface modification, melt blending reaction net forming, forming and the like. The obtained elastomer sole material not only has excellent wear resistance and mechanical properties, but also can realize self-repair of graded response aiming at damages of different degrees, and the service life of the material is remarkably prolonged.

The invention relates to the technical field of high polymer material processing, in particular to a blow molding method of a composite toughened film, which comprises the following steps: step 1, preheating matrix resin in preheating equipment; 2, feeding the mixed raw materials into a double-screw extruder for melt blending; 3, feeding the dried composite particles into a hopper of a single-screw blow molding extruder; 4, adjusting the air volume and the air pressure of the cooling system according to the monitoring result; and 5, the formed film pipe is folded into a flat shape through a guide component and led out through a traction roller, the traction speed and the extrusion speed are coordinated to control the traction ratio, corona treatment is conducted on the surface of the thin film to improve the surface energy, then rolling tension is controlled for rolling, and the rolling tension is controlled according to the elasticity and thickness of the thin film to prevent excessive stretching or loosening. The uniform distribution and proper compatibility of the composite toughening component improve the toughness of the film, and maintain the strength and barrier property of the film.

The invention relates to a special engineering plastic polyethersulfone microcellular foam material and a preparation method thereof, belongs to the technical field of high polymer material foaming, and solves the problem that high foaming ratio, a microcellular structure and excellent mechanical properties cannot be simultaneously obtained when a macromolecular polyethersulfone material adopts an injection foaming technology in the prior art. The method comprises the following steps: step 1, pretreating raw materials; 2, melt blending: mixing the PES base material, the second component, the functional filler, the cross-linking agent and the foam stabilizer, carrying out melt blending, granulating, and drying to obtain granules; 3, injection foaming: injecting the granules into an injection machine, adding a composite foaming agent into the injection machine, mixing, and performing injection foaming molding to obtain an injection-molded foaming material; and 4, curing: irradiating the injection-molded foam material with rays to obtain the special engineering plastic PES microcellular foam material.

The invention discloses a melt blending preparation process of a semiconductive shielding material for an ultrahigh-pressure crosslinked polyethylene cable, which comprises the following steps: S1, premixing low-density polyethylene and an ethylene-vinyl alcohol copolymer in proportion, the vinyl alcohol chain segment content of the ethylene-vinyl alcohol copolymer being 25%-45%; s2, performing plasma surface treatment on carbon black, and compounding the carbon black with carbon nanotubes to form a conductive filler system; s3, under the protection of inert gas, adding the matrix resin in the step S1 and the conductive filler in the step S2 into a double-screw extruder in stages, and synchronously adding a hindered phenol and phosphite compound antioxidant; and S4, carrying out segmented mixing under the temperature gradient of 160-210 DEG C. Through synergistic compounding of the plasma surface modified carbon black and the carbon nanotubes and in combination with a staged feeding process, directional dispersion of the conductive filler is realized, a three-dimensional interpenetrating conductive network is formed, and the local electric field homogenization capability of the ultrahigh-voltage cable is remarkably improved.

The invention discloses modified asphalt and a preparation process thereof, and belongs to the technical field of road materials. The modified asphalt is prepared from 80-90 parts of matrix asphalt, 4-8 parts of butadiene styrene rubber, 2-5 parts of nano montmorillonite, 1.5-3 parts of core-shell structure nanoparticles (the core is SiO2 grafted with-SO3H, the middle layer is thermo-sensitive PNIPAM containing a photoinitiator, and the shell is GO grafted with a hindered phenol antioxidant group and a photosensitive coumarin group), 1-3 parts of a compatilizer, 3-6 parts of a plasticizer and 0.3-0.8 part of an antioxidant. The preparation process comprises the following steps: pretreating the modifier master batch, performing melt blending, performing high-speed shearing, performing ultrasonic dispersion, cooling, discharging and the like. The light response crosslinking mechanism is utilized, crosslinking is achieved under illumination through the light response characteristic of the core-shell structure nanoparticles, the high-temperature stability, the anti-aging performance and the fatigue life of the modified asphalt are remarkably improved, and the modified asphalt is suitable for the fields of high-grade road construction and the like.

The invention discloses a preparation method of an environment-friendly degradable single-sided perspective sticker, and belongs to the technical field of modified nano materials. The method comprises the following steps: (1) preparation of a multi-layer composite structure: mixing polylactic acid and poly (butylene succinate), adding nano-montmorillonite and a surface modifier, and carrying out melt blending to form a first-layer melt; stirring poly (butylene adipate-co-terephthalate) and fluorescent carbon nanodots to form a second layer of melt; the first layer, the pressure-sensitive adhesive layer and the second layer are co-extruded and compounded to form a film blank. And (2) construction of the nano-film: biaxially stretching the film blank, imprinting a micropore array, dipping in the silver nanoparticle suspension, and drying to obtain the nano-film. And (3) coating functionalization treatment: immersing into a fluorine-containing nano coating solution, and curing. And (4) post-treatment: carrying out secondary curing. The obtained single-sided perspective sticker is suitable for the fields of buildings, vehicle privacy films and the like, and solves the problems of serious pollution and slow degradation of a traditional sticker.

The invention belongs to the field of flame-retardant materials, and particularly relates to a flame-retardant wood-plastic composite material and a preparation method thereof. Raw camphorwood powder is subjected to alkali treatment and hyperbranched silicon dioxide grafting treatment and then is subjected to melt blending with polypropylene, piperazine pyrophosphate and melamine phosphate, and the wood-plastic composite material with the intumescent flame-retardant effect is prepared. Limit oxygen index, vertical combustion, thermogravimetry, cone calorimetry and other tests show that the prepared wood-plastic composite material has excellent flame retardance, the limit oxygen index can reach 36.8%, the vertical combustion test reaches the V-0 grade, the total smoke release amount is reduced to 45.3% of that of raw materials, the flame retardance, smoke suppression and other performance are remarkably improved, and the wood-plastic composite material has good application potential.

The invention relates to the technical field of polyether-ether-ketone composite materials, in particular to a conjugated polythiophene-polyether-ether-ketone-based high-antibacterial coating and a preparation method thereof.The preparation method comprises the steps that hydroxyl modified boron nitride with photocatalytic capacity and aminated PEEK are subjected to melt blending to generate chemical bonding, and a BN-OH / PEEK-NH2 composite fine powder material is formed; then carrying out oxidative polymerization on the BN-OH / PEEK-NH2 composite fine powder and a thiophene monomer under the action of an oxidizing agent, carrying out in-situ synthesis to obtain a polythiophene / BN-OH / PEEK-NH2 conjugated composite material, and subsequently spraying the polythiophene / BN-OH / PEEK-NH2 conjugated composite material to the surface of a base material to prepare a composite coating with excellent antibacterial property, high thermal stability and low friction coefficient; the antibacterial rate of the coating on escherichia coli and staphylococcus aureus under illumination reaches 90% or above, and the coating is suitable for the medical antibacterial field.

The invention relates to the technical field of high polymer material modification and processing, in particular to a modification formula and production process of an impact-resistant and high-heat-resistant MPP cable protection tube, and the formula comprises 60-80 parts of a polypropylene base material, 8-15 parts of a nano-composite reinforcing agent, 5-12 parts of a heat-resistant modifier, 3-8 parts of an impact-resistant modifier and the like. The production process comprises the steps of nanofiller surface functionalization, multi-stage melt blending, dynamic vulcanization forming, pulse type vacuum setting and online detection, and the prepared pipe is excellent in impact resistance and heat resistance and high in size precision. The pipe provided by the invention has the advantages of zero fracture in drop hammer impact, vicat softening temperature of 152 DEG C, ring stiffness of 60.16 kN / m < 2 > and small dimensional deviation; the process improves filler dispersity, has low rejection rate and energy consumption, has comprehensive performance superior to that of traditional products, and is suitable for complex working conditions.

The present invention discloses a method for preparing a modified PHA composite material using a twin-screw extruder and its application. The method is carried out by in-situ melt blending of polyhydroxyalkanoate PHA, polybutylene terephthalate-adipate PBAT, polyvinyl alcohol PVOH and a chain extender in a twin-screw extruder, so that a multifunctional epoxy or isocyanate chain extender reacts with the terminal groups of PHA, PBAT and PVOH molecules to form a partially cross-linked or grafted structure, thereby achieving enhanced compatibility, improved thermal stability and significant improvement in barrier properties. Experiments have shown that the modified PHA composite material obtained by the present invention has high strength, high elongation, excellent water and oxygen barrier properties and biodegradable properties, and meets the stringent requirements for mechanical properties and barrier properties in multiple fields such as food packaging, agricultural mulch and medical consumables. The preparation method of the present invention is simple and efficient, and can be used for large-scale continuous production on existing twin-screw extrusion equipment.

The invention discloses a high transparency and high toughness polyamide fiber preparation method, which comprises: S10: carrying out melt blending on polyamide and an ethylene-alpha-olefin copolymer elastomer, and extruding under the high shear action to obtain a modified melt; s20, the modified melt is extruded through a spinneret plate to form nascent filaments, the nascent filaments are fed into a cooling area to be rapidly cooled, and nascent fibers are obtained; the retention time of the nascent filaments in the cooling area is 0.1-0.3 second, nitrogen is adopted as a cooling medium in the cooling area, and the temperature of the nitrogen is 10-14 DEG C; s30, carrying out hot stretching treatment on the nascent fiber to obtain a stretched fiber; and S40, carrying out heat setting treatment on the stretched fiber to obtain the polyamide fiber. The polyamide fiber prepared by the method has good toughness and relatively high transparency.

The invention relates to the technical field of rubber-plastic composite flame-retardant materials, and provides a graphite rubber-plastic composite flame-retardant material and a preparation method thereof.The preparation method comprises the following processes that nitrile rubber, polyvinyl chloride, dioctyl phthalate, modified expandable graphite, a stabilizer, sulfur and an anti-aging agent are added into a high-speed mixer and mixed to be uniform, and a premix is obtained; and feeding the premix into a double-screw extruder, and carrying out melt blending, extrusion and vulcanization to obtain the composite flame-retardant material. The preparation method has the beneficial effects that the modifier is combined with the expansible graphite and compounded with the nitrile rubber, the polyvinyl chloride and other base materials, so that the flame retardant property and the mechanical property of the prepared composite material are remarkably improved.

The invention relates to the technical field of environment-friendly materials, and discloses a high-strength degradable packaging material and application of the high-strength degradable packaging material in cosmetic packaging materials.The preparation method of the high-strength degradable packaging material comprises the steps that polylactic acid, vanillic aldehyde modified polyester, polyadipic acid, triethyl citrate, calcium stearate and an antioxidant are added into a high-speed mixing machine, and the mixture is stirred to be uniform; mixing at 60 to 80 DEG C for 10 to 20 minutes to obtain a mixed material; the mixed material is subjected to melt blending through a double-screw extruder, the blending temperature is 160-180 DEG C, the screw rotating speed is 250-300 rpm, extrusion granulation and drying are conducted, and the high-strength degradable packaging material is obtained. The high-strength degradable packaging material can be applied to cosmetic packaging materials such as bottle bodies, bottle caps, hoses and packaging boxes. The prepared packaging material is high in mechanical strength and has good degradability and flame retardance.

The invention relates to the technical field of films, in particular to a high-surface tension aluminized base film and a preparation method thereof. The method comprises the following steps: grafting modified fumed silica with a silane coupling agent KH-570, and grafting a ternary polymerization shell layer composed of 2-acrylamide-2-methylpropanesulfonic acid, lauryl methacrylate and glycidyl methacrylate on the surface of the modified fumed silica to obtain organic anti-sticking silica; secondly, synthesizing an aromatic sulfonated polyester prepolymer, loading nano titanium dioxide, and carrying out melt blending extrusion with polypropylene to form polar cluster polypropylene master batches; and finally, blending polypropylene resin, the master batch and maleic anhydride grafted polypropylene, and carrying out melt extrusion, air cooling and slow cooling and two-way stretching molding. The obtained base film is high in surface tension, high in aluminized layer adhesive force, excellent in oxygen and water vapor barrier property, good in thermal stability and suitable for the field of high-end packaging.

The invention discloses a recoverable high-barrier-property multilayer composite film and a preparation method thereof. The composite film adopts a five-layer symmetrical structure, namely a heat sealing layer, a first bonding layer, a blocking layer, a second bonding layer and a surface protection layer. Wherein the barrier layer is a montmorillonite modified ethylene-vinyl alcohol copolymer, and montmorillonite is modified by a carboxyl functionalized ammonium bromide intercalator; the bonding layer is maleic anhydride grafted polylactic acid; the heat sealing layer contains modified composite filler; the surface protection layer is a polyethylene / graphene modified coupling agent composite system. The preparation method comprises the steps of intercalation modified montmorillonite preparation, barrier layer material melt blending, five-layer co-extrusion casting, gradient hot pressing and curing treatment. The problems that a traditional high-barrier film is unrecyclable, the interlayer binding force is weak and the high-temperature stability is poor are solved, the ultrahigh barrier performance that the oxygen transmission rate is smaller than or equal to 0.5 cm < 3 > / (m < 2 >. 24 h) and the water vapor transmission rate is smaller than or equal to 1.0 g / (m < 2 >. 24 h) is achieved, and the mechanical property retention rate is larger than or equal to 85% after recycling and re-pelletizing.

The invention discloses a self-degradable granular temporary plugging agent for fracturing as well as a preparation method and application thereof, and relates to the technical field of oilfield chemistry. The temporary plugging agent is prepared by melting, blending and crushing the following materials in percentage by mass: 70%-85% of poly (3-hydroxybutyrate-co-4-hydroxybutyrate), 10%-20% of poly (3-hydroxybutyrate-co-4-hydroxybutyrate), 10%-20% of poly (3-hydroxybutyrate), 2%-10% of an auxiliary agent for assisting degradation; 10%-15% of nano silicon dioxide; 1%-7% of sodium starch glycolate. The temporary plugging agent disclosed by the invention contains the disintegrant glycolic acid starch sodium which is extremely high in water absorption capacity, and can rapidly absorb water and expand the volume of the temporary plugging agent by 250-300 times, so that the temporary plugging agent expands to generate cracks, on one hand, gaps among particles can be reduced after the temporary plugging agent absorbs water and expands in the early stage of plugging, and the compactness of a whole plugging layer is increased; on the other hand, cracks are generated on the surface of the temporary plugging agent after expansion, and water can permeate into temporary plugging agent particles from the cracks, so that the contact area between the temporary plugging agent and the water is increased, the degradation of the temporary plugging agent is promoted, and the overall degradation time is shortened.

The present invention discloses a self-degradable particle temporary plugging agent for fracturing and its preparation method and application, relating to the field of oilfield chemical technology. According to mass percentage, the temporary plugging agent is obtained by melt blending and crushing the materials including the following components: poly (3-hydroxybutyric acid-co-4-hydroxybutyrate), 70%-85%; auxiliary agent for auxiliary degradation, 2%~10%; nano silicon dioxide 10%~15%; sodium starch glycolate, 1%~7%. The temporary plugging agent of the present invention contains disintegrant sodium starch glycolate, which has a strong water absorption capacity and can quickly absorb water and expand its own volume by 250~300 times, so that the temporary plugging agent expands and cracks appear. On the one hand, in the early stage of plugging, the temporary plugging agent can reduce the gap between particles after absorbing water and expanding, thereby increasing the density of the entire plugging layer, thereby improving the plugging ability. On the other hand, cracks are generated on the surface of the temporary plugging agent after expansion, and water can penetrate into the interior of the temporary plugging agent particles from the cracks, which increases the contact area between the temporary plugging agent and water, thereby promoting its degradation and shortening the time of overall degradation.