793 results about "Melt flow index" patented technology

The invention discloses a technology for manufacturing a thin film by recycling and calendering a polytetrafluoroethylene material, and belongs to the technical field of high polymer material recycling and processing, the technology for manufacturing the thin film by recycling and calendering the polytetrafluoroethylene material comprises the following steps: crushing waste products, and carrying out three-stage screening impurity removal and melt index detection; after being cleaned by supercritical carbon dioxide, the qualified material is mixed with industrial by-product filler, waste tire rubber powder and the like, low-temperature mixing is conducted through a double-screw extruder, and mixing parameters are automatically regulated and controlled through a tension sensor; performing calendaring forming by a five-roller calendaring unit, preheating the first two rollers, performing differential stretching by the middle three rollers, engraving a micro groove by the third roller, and controlling the thickness precision to be + / -3% by an online thickness gauge; the film is slit after being compounded according to requirements, and scrap edges are crushed and recycled. The method realizes efficient recovery of waste polytetrafluoroethylene, and has the advantages of thorough impurity removal, stable performance, environmental protection and energy saving.

The invention provides a bio-based 1, 4-butanediol composition and a preparation method thereof, and polyester prepared from the bio-based 1, 4-butanediol composition, the bio-based 1, 4-butanediol composition comprises bio-based 1, 4-butanediol, an acidic compound, a nitrogen-containing compound and acetal; the content of acetal in the bio-based 1, 4-butanediol composition is less than or equal to 195ppm. According to the invention, polyester prepared by taking the bio-based 1, 4-butanediol composition as a raw material has a low color value and a low melt index.

The invention discloses a continuous fiber reinforced thermoplastic composite material and a preparation method thereof. The continuous fiber reinforced thermoplastic composite material comprises 35-40% of a polypropylene matrix with a melt index of 10-30 g / 10 min; 55% of continuous fibers are selected from glass fibers, carbon fibers or basalt fibers which are arranged in one direction, and the monofilament diameter is 9-15 microns; the intumescent flame retardant and the ammonium polyphosphate are compounded according to the mass ratio of 2: 1; 1-2% of an interface modifier, wherein a silane coupling agent KH-570 or PP-g-MAH is selected and used; the roughness Ra of the aluminum foil layer is 1.5-2.5 microns; under the condition of basically ensuring that the overall performance of the material is not greatly influenced, the application capability of the material is expanded, and the fireproof and flame-retardant capability of the material is improved, so that a thermoplastic composite material scheme can also be adopted under various harsh use conditions.

The invention belongs to the technical field of modified special plastics, and provides a polysulfone composite material for an extremely-high-temperature-resistant safety helmet and a preparation method and application thereof.The polysulfone composite material is prepared from, by mass, 24-40% of bisphenol A type polysulfone resin, and the melt index gt of the bisphenol A type polysulfone resin is measured at the temperature of 343 DEG C and 2.16 kg; the oxygen index gt is 5 g / 10 min; 30); the glass transition temperature of the nylon resin is greater than or equal to 130 DEG C, and the relative viscosity of the nylon resin is 1.8-2.2; 3-6% of a compatilizer; 5 to 10% of a maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer; 25-35% of glass fiber; 0.3%-0.7% of an antioxidant; and 0.3-0.7% of a lubricant. The composite material is prepared from the raw materials, and the prepared safety helmet has excellent comprehensive mechanical properties, such as combustion resistance, 150 DEG C bending strength, impact absorbing force and maximum lateral rigidity deformation at 150 DEG C.

The invention belongs to the technical field of composite materials, and particularly discloses a polypropylene composite material, a preparation method thereof and automobile interior and exterior ornaments.The polypropylene composite material is prepared from, by weight, 40-60 parts of first polypropylene resin, 15-25 parts of second polypropylene resin, 6-25 parts of flexibilizer, 18-23 parts of talcum powder, 0.1-1.5 parts of weather-proof agent and 1.5-3 parts of antioxidant; wherein the melt index of the first polypropylene resin is smaller than that of the second polypropylene resin; the mesh number of the talcum powder is 2250 to 5000. The polypropylene composite material has relatively high low-temperature impact resistance and relatively high rigidity, and can improve the safety performance of an automobile when being applied to interior and exterior ornaments of the automobile.

Disclosed is a composite sheet for package comprising an outer layer, an intermediate layer, and an inner layer sequentially stacked in a first direction, wherein the inner layer comprises a first LDPE with a melt flow index of 3.5-7.5 g / 10 min (190°C, 2.16 kg). Further disclosed a method for producing a composite sheet for package, a sleeve, and a package container.

The invention discloses a method for testing a melt index. The method comprises the following steps: preheating a melt charging barrel to a preset temperature, and carrying out heat preservation for a first preset time; feeding to be measured is loaded into a containing cavity of a melting charging barrel, a piston rod is inserted into the melting charging barrel, a mass piece with the first weight is added to the piston rod, the feeding to be measured is melted into molten feeding under the pressure of the piston rod and is compacted, and therefore falling materials with the preset length are exposed out of a discharging opening of the melting charging barrel; switching the weight of the mass piece on the piston rod from the first weight to the second weight, so that the to-be-detected feed flows out of the discharge port under the pressure of the piston rod and is cut to obtain a plurality of sections of first to-be-detected samples, and calculating the melt index of the to-be-detected feed; the range of the first weight is 2.16 kg to 10 kg, and the range of the preset length is 1 cm to 30 cm. Therefore, the air in the melt charging barrel can be exhausted, the components of the to-be-tested feed are more uniform, the uniformity of the first to-be-tested sample is improved, the fluctuation of the tested melt index is reduced, and the accuracy of the test result is improved.

The invention relates to the field of films, in particular to a light-weight anti-shrinkage BOPP (biaxially-oriented polypropylene) laser film and a preparation method thereof.The laser film comprises a mold pressing layer, an upper secondary surface layer, a core layer, a lower secondary surface layer and a light layer which are sequentially arranged, the total thickness is 13-15 microns, and the mold pressing layer comprises ethylene-propylene binary co-polypropylene; the weight-average molecular weight of first homo-polypropylene in the core layer is 250000-35000 g / mol, the number-average molecular weight of the first homo-polypropylene in the core layer is 90000-160000 g / mol, the molecular weight distribution index of the first homo-polypropylene in the core layer is 2-3, the upper secondary surface layer and the lower secondary surface layer are composed of modified polypropylene with the melting point of 170-180 DEG C and the melt index of 2-4 g / 10 min, the grafting rate of N-vinyl pyrrolidone is 2-5%, and the light layer comprises second homo-polypropylene. The modified polypropylene subjected to NVP grafting modification is adopted to form the upper secondary surface layer and the lower secondary surface layer, and the weight-average molecular weight, the number-average molecular weight and the molecular weight distribution index of the first homo-polypropylene are limited, so that the BOPP laser film is light in weight; the heat shrinkage rate of the laser film is reduced, the low haze of the laser film is ensured, and smooth production of the laser film is ensured.

The invention relates to the field of preparation of non-woven materials, and discloses a preparation method of a two-component spunbonded non-woven material, which comprises the following steps: (1) performing sheath-core two-component spinning on molten metallocene polyethylene and molten polyester, the melt index of the metallocene polyethylene being 5-10g / 10min at 240 DEG C under the load of 2.16 kg; (2) the bi-component trickles obtained in the step (1) are subjected to double-side air blowing cooling forming, and filaments are obtained; (3) carrying out wide slit type airflow drafting on the filaments in the step (2), and then carrying out filament separation and net laying; and (4) the fiber web laid in the step (3) is sequentially subjected to hot air setting and hot rolling bonding reinforcement, and the hot air temperature of hot air setting ranges from 110 DEG C to 140 DEG C. By adopting the method, the high-wrinkle skin-core double-component spunbond non-woven material with higher strength and better flexibility can be obtained.

The invention discloses a biodegradable polyester material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The biodegradable polyester material provided by the invention is prepared from the following components in parts by mass: 78 to 97 parts of biodegradable polyester composition, 3 to 22 parts of surface modified calcium carbonate, 0.05 to 0.55 part of chain extender and 0 to 1 part of processing aid, the biodegradable polyester composition comprises PBAT (poly (butylene adipate-co-terephthalate)), PLA (polylactic acid) and PPC (polypropylene carbonate), wherein the mass ratio of the PBAT to the PLA to the PPC is (80-90): (1-10): (1-10); the melt index of the PBAT at 190 DEG C / 2.16 kg is less than or equal to 10 g / 10 min; the molar content of D-lactic acid in the PLA is greater than or equal to 2%; the D50 particle size of the surface modified calcium carbonate is less than or equal to 2.2 microns. The biodegradable polyester material provided by the invention has excellent delayed edge sealing performance and puncture strength.

The invention discloses a polypropylene composite material modified by a branched polyolefin material. The polypropylene composite material comprises the following components in parts by weight: 10-40 parts of polypropylene with a high melt index, 30-50 parts of impact-resistant polypropylene with a low melt index, 10-35 parts of the branched polyolefin material and 15-25 parts of filler. The branched polyolefin material has a long and short branched chain structure, and the weight-average molecular weight of the branched polyolefin material is 2000-8000000 g / mol; the branching degree is 40-180 / 1000 DEG C, and the melt index is 0.01-20 g / 10 min under the conditions that the temperature is 190 DEG C and the load is 2.16 kg. The technical problem that the mechanical property of an ethylene-butylene copolymer as an elastomer is not better than that of an ethylene-octylene copolymer is solved by adopting the light olefin as a raw material and optimizing the molecular structure and combination of the material, and compared with the traditional POE ethylene-octylene copolymer, the light olefin is adopted as the raw material, so that the raw material cost is reduced, and the economic benefit is improved; the low-temperature toughness and the mechanical property of the polypropylene composite material are obviously improved, and the polypropylene composite material is especially suitable for the plastic modification field.

The invention provides a shoe material master batch based on coffee grounds and a preparation method thereof. The shoe material master batch comprises the following raw materials in parts by mass: 100 parts of coffee grounds, 30-70 parts of a thermoplastic material, 5-10 parts of an isocyanate-terminated polyurethane prepolymer, 3-10 parts of a compatibilizer, 1-5 parts of a filler and 0.1-1 part of an antioxidant. The content of the coffee grounds in the shoe material master batch is 50% or above, the isocyanate-terminated polyurethane prepolymer is applied to the highly-doped coffee grounds system, the interface bonding force between the coffee grounds and a thermoplastic material matrix and the melt supporting capacity can be remarkably improved through the cooperation of the isocyanate-terminated polyurethane prepolymer and the filler, the shoe material master batch has the good melt index and melt strength, and the service life of the shoe material master batch is prolonged. The foaming material has good processability and foaming performance, so that the foaming material can be better applied to foaming shoe materials.

Processes for producing activated chromium catalysts such as titanated chromium / silica catalysts are disclosed, and these processes utilize a multistep process involving exposure to inert and oxidizing atmospheres at specific temperature conditions. The resulting activated chromium catalysts have unexpectedly high melt index potential and can produce ethylene-based polymers with lower gel counts in addition to higher melt indices.

The invention discloses a cross-linking type biodegradable POF heat shrink film and a preparation method thereof, and belongs to the technical field of heat shrink films, and the cross-linking type biodegradable POF heat shrink film is characterized by comprising three layers of films which are sequentially attached, each of the first-layer film and the third-layer film comprises the following raw materials in percentage by weight: 89.5-94% of PP, 2-6% of degradable master batch, 0.5-3% of an anti-blocking agent and 1-4% of a slipping agent; the second-layer film is prepared from the following raw materials in percentage by weight: 30 to 35 percent of LLDPE-A, 9 to 14.5 percent of toughening agent, 0.5 to 1 percent of degradable master batch, 40 to 45 percent of LLDPE-B and 10 to 15 percent of metallocene LLDPE; the melt index of the LLDPE-A is 2.5 g / 10min, the melt index of the LLDPE-B is 2.1 g / 10min, the melt index of the metallocene LLDPE is 1.0 g / 10min, and through the synergistic effect between the LLDPE with different melt indexes and the flexibilizer, the low-temperature tear resistance of the heat shrink film is effectively improved.

The invention provides a copolymerization type high-crystallinity polypropylene material as well as a preparation method and application thereof. The relative molecular weight distribution PD of the copolymerization type high-crystallinity polypropylene material is 3.5-5; the content XS [%] of a xylene soluble substance is 5-23; the intrinsic viscosity ratio k of the xylene soluble substance to the crystalline phase is 1.6-2.9; the relative molecular weight distribution PD, the crystallization enthalpy delta Hc [kJ / kg], the xylene soluble content XS, the flexural modulus FM [MPa], the simply supported beam impact strength ak [kJ / m < 2 >], the intrinsic viscosity ratio k of the xylene soluble to the crystalline phase and the melt index MFR [g.10 min <-1 > meet a certain relational expression. Tests prove that the copolymerized high-crystallinity polypropylene material has excellent comprehensive properties, such as higher crystallization enthalpy, higher fluidity, higher bending modulus, higher impact strength and the like, and is excellent in processability.

The invention relates to the technical field of automation, in particular to a polyolefin melt index prediction method and device, equipment and a storage medium. According to the method, a polymerization parameter set of to-be-predicted polyolefin is obtained, and the polymerization parameter set is input into a trained index prediction model, so that a target prediction value of the polyolefin melt index output by the index prediction model is obtained. The index prediction model is obtained by performing self-supervised learning processing on a labeled sample set and an unlabeled sample set to obtain a self-supervised sample set and performing model training on the self-supervised sample set based on semi-supervised learning. Therefore, the data characterization capability of the index prediction model can be improved through the self-supervised learning process, and limited labeled sample data is utilized for supplement through semi-supervised learning, so that when the number of labeled samples is small, a high-precision polyolefin melt index prediction result can still be obtained, and the prediction accuracy of the polyolefin melt index is improved. And the prediction accuracy of the polyolefin melt index is improved.

The invention relates to the field of polymer composite board processing, and particularly discloses a light fiber reinforced thermoplastic resin composite board and a preparation method thereof.The light fiber reinforced thermoplastic resin composite board comprises a PP upper adhesive film layer, a fibrofelt, a PP lower adhesive film layer and PET non-woven fabric; each of the PP upper adhesive film layer and the PP lower adhesive film layer consists of a low-melt-index PP adhesive base film and a high-melt-index PP adhesive film; the low-melt-index PP adhesive base film is in contact with the fiber felt; the melt index of the low-melt-index PP rubber base film is 2-10 g / 10 min, and the melt index of the high-melt-index PP rubber base film is 100-150 g / 10 min; the preparation method comprises the following steps: preparing the PP upper adhesive film layer and the PP lower adhesive film layer; the fiber felt is located between the PP upper adhesive film layer and the PP lower adhesive film layer, the PET non-woven fabric is attached to the other side of the PP lower adhesive film layer, rolling forming is conducted at the temperature of 280-320 DEG C, and a composite board is obtained; the adhesive has the advantages of stripping resistance and good adhesion stability of each layer.

The invention belongs to the technical field of high polymer materials, and particularly relates to a polyolefin composite material as well as a preparation method and application thereof. The polyolefin composite material is prepared from the following raw materials: polyethylene, a polyolefin toughening agent, a compound flame retardant and a filler, the melt index of the polyethylene at 190 DEG C / 2.16 kg is greater than or equal to 18 g / 10 min, and the bending modulus is less than or equal to 160 MPa; the polyolefin toughening agent is selected from at least one of an ethylene-propylene copolymer, an ethylene-butylene copolymer and an ethylene-vinyl acetate copolymer, and the melt index at 230 DEG C / 2.16 kg is greater than or equal to 9 g / 10 min; the compound flame retardant comprises tetrabromobisphenol S bis (2, 3-dibromopropyl) ether, antimony trioxide and hydroquinone bis (diphenyl phosphate), and the filler is at least one of talcum powder, barium sulfate and wollastonite. Through specific types of polyethylene, the polyolefin flexibilizer, the compound flame retardant and the filler, excellent flame retardance and toughness can be obtained.

The invention belongs to the technical field of high-voltage cross-linked polyethylene compositions, and particularly relates to a water-tree-resistant cross-linked polyethylene insulating composition for a high-voltage direct-current submarine cable and a preparation method and application of the water-tree-resistant cross-linked polyethylene insulating composition. The insulating composition comprises the following components in parts by weight: 80-120 parts of low-density polyethylene resin with a melt index of 1.9-2.1 g / 10min; 0.2 to 0.3 part of a composite antioxidant; 1.25 to 1.85 parts of a composite cross-linking agent; 0.2 to 0.3 part of a scorch inhibitor; 8-12 parts of a water-inhibiting master batch; wherein the water-inhibiting master batch is prepared from 80 to 120 parts of composite polyolefin resin, 6 to 9 parts of composite water-inhibiting agent, 3.6 to 5.4 parts of maleic anhydride graft and 0.15 to 0.25 part of antioxidant; the composite water inhibitor comprises polyethylene glycol and oleamide in a mass ratio of (8-12): 1. The insulation composition can inhibit insulation scorching and resist insulation water tree growth, and is high in gel content, high in extrusion cabling speed and stable in production process.

The invention discloses a lightweight high-elasticity modified EVA (ethylene vinyl acetate) foam material, which is prepared from the following ingredients in parts by weight: 50 to 90 parts of ethylene-vinyl acetate copolymers, 10 to 50 parts of branched polyolefin elastomers, 2 to 5 parts of foaming agents, 0.5 to 2 parts of foaming auxiliary agents, 0.5 to 2 parts of cross-linking agents, 0.6 to 3 parts of lubricating agents, 1 to 30 parts of filling agents and 5 to 10 parts of compatilizers. The branched polyolefin elastomers have long and short branched chain structures, and the weight-average molecular weight is 20000 to 8000000 g / mol; the branching degree is 50-120 / 1000 DEG C, and the melt index is 0.1-20 g / 10 min under the conditions that the temperature is 190 DEG C and the load is 2.16 kg. The light olefin raw material is adopted, the branching degree of the elastomer is improved, the toughening performance is improved, the composite compatilizer is combined, the melt compatibility is improved, the toughening effect of the branched polyolefin elastomer is further improved, the normal-temperature elasticity and the low-temperature elasticity of the foaming material are remarkably improved, the comfort and durability of a shoe sole are improved, and the service life of the foaming material is prolonged. The hardness change of the foaming material at low temperature is obviously reduced, and the foaming material has relatively high application and popularization values.

The present application relates to the field of polymer materials, and specifically discloses an easy-to-process LDPE particle with a high content of an opening lubricant and a preparation method thereof. An easy-to-process LDPE particle with a high content of an opening lubricant comprises the following raw materials in parts by weight: 100 parts of LDPE resin, 0.2-0.3 parts of an opening lubricant, 0.3-0.4 parts of a lubricant and 5-7 parts of ammonium polyphosphate; the preparation method thereof is: LDPE resin, an opening lubricant, a lubricant and ammonium polyphosphate are uniformly mixed, melted, and extruded into granules. The easy-to-process LDPE particles of the present application have a large melt index, low viscosity, good fluidity during processing, are not easy to adhere to metals and produce agglomeration, and when made into plastic film products, have high mechanical strength and high transparency.

The invention relates to the technical field of material performance detection, in particular to a rapid testing method for thermal aging failure of an oil and gas pipeline anticorrosive coating material, which comprises the following steps: testing oxidation induction time t of a sample; respectively carrying out thermal aging with different time lengths at 150 DEG C, measuring and calculating A (tri) / A (on) and a melt index change rate, establishing a linear equation of the A (tri) / A (on), and calculating A '(tri) / A' (on) corresponding to 35% of the melt index change rate; carrying out thermo-oxidative aging on the sample at different time lengths, measuring and calculating A (tri) / A (on), and obtaining aging time t'according to A '(tri) / A' (on); carrying out oxidation induction time test on the thermally aged material to obtain a rate coefficient k; and calculating the aging time corresponding to the material failure critical point. The test method provided by the invention can rapidly characterize the thermal aging failure critical point of the anticorrosive coating material, and provides a scientific basis for development of the material.

The invention relates to the field of medicine packaging, in particular to cycloolefin polymer hydride, a resin composition, a resin forming body and a medicine packaging material. The cycloolefin polymer hydride provided by the invention has high moisture resistance and grease resistance under a specific content ratio of a repeating unit with a monocyclic structure and a repeating unit containing a bridged ring structure, and has good flowability in the process of further melting and forming the polymer hydride into a resin forming body. And moreover, the metal residual quantity is low, the glass transition temperature is relatively high, and the method is very suitable for being applied to preparation of medicine packaging materials. In the test of the invention, the glass transition temperature of the cycloolefin polymer hydride provided by the invention is up to 139 DEG C, the melt index is up to 4.4 g / 10 min, the moisture resistance is up to 1.6 (g / m < 2 > 24 h) / 100 [mu] m, and the oil resistance is grade A.

The invention relates to a method and a device for predicting a melt index in polyformaldehyde production, equipment and a medium, and relates to the field of polyformaldehyde production, and the method comprises the following steps: generating different time delay information by using a wolf pack algorithm; performing modeling training on the process data with the obtained time delay information through a support vector regression model to obtain root-mean-square errors generated by training data corresponding to different time delay information; optimizing the time delay information by taking the root-mean-square error as an evaluation criterion and by means of a wolf pack algorithm to obtain optimal time delay information; and establishing a soft measurement model by using the obtained optimal time delay information and process data through a radial basis function neural network, and predicting according to the soft measurement model to obtain an estimated melt index. According to the method provided by the invention, the optimal time lag information in polyformaldehyde production is obtained based on the combination of the wolf pack algorithm and the support vector regression, and then the prediction model is established by the time lag information and the production data through the radial basis function neural network, so that efficient and accurate prediction of the melt index is realized, and efficient production of polyformaldehyde is facilitated.

Embodiments of a grafted polyethylene comprise a reaction product of a polyethylene having a melt index (at 190° C., 2.16 kg) of at least 0.75 g / 10 min, from 0.5 wt. % to 10 wt. % of metal acrylate or metal methacrylate at least partially grafted on the polyethylene, and from 0.1 wt. % to 10 wt. % of one or more metal carboxylates, wherein the metal carboxylate does not have any terminal unsaturation.

The invention discloses a continuous foaming composite process for a pearl wool coiled material and a waste gas recovery system thereof, and belongs to the technical field of pearl wool processing. Aiming at the problems of low efficiency and waste gas pollution of a traditional intermittent process, the process realizes continuous production through raw material selection (the melt index of LDPE is 1.0-2.5 g / 10min), drying and mixing pretreatment, melting and plasticizing through a twin-screw extruder, injection of foaming agents such as butane under the pressure of 8-12MPa, extrusion foaming at a die head of 140-160 DEG C and combination of air-cooling and water-cooling shaping. The compounding link comprises multiple processes such as hot pressing and co-extrusion to adapt to different base materials, after-treatment is conducted through trimming, taper tension coiling and standing stress release, the product density fluctuation is + / -3%, and the peel strength is larger than or equal to 3 N / cm. According to the waste gas recovery system, negative pressure collection is conducted through a closed gas collecting hood, indirect cooling and alkali liquor spraying pretreatment are conducted, activated carbon adsorption concentration and catalytic combustion purification are conducted, the VOCs removal rate is larger than or equal to 98%, the emission concentration is smaller than or equal to 50 mg / m < 3 >, and efficient production and environmental protection benefits are achieved.

The invention provides a modified engineering plastic melt index real-time monitoring method which comprises the following steps: determining a melt index difference value of adjacent monitoring points by acquiring a melt index value of each section of an extrusion production line; obtaining the number of shearing cycles of the extrusion production line, identifying the fiber shearing damage degree of each section according to the melt index difference and the number of shearing cycles to obtain fiber damage distribution, and determining the fiber fracture position according to the fiber damage distribution; the melt index difference value corresponding to the fiber fracture position is analyzed by obtaining the melt index of the fiber fracture position, and the monitoring point interval is dynamically adjusted through the melt index difference value; and obtaining the melt index value and the fiber shortening amplitude after the interval adjustment of the monitoring points, and comparing the melt index change and the fiber length loss of each monitoring point to obtain the corresponding distribution of the fiber shortening amplitude and the melt index value.

The invention discloses an intrinsic anti-ultraviolet aging bio-based polyester elastomer and a preparation method thereof, and the preparation method comprises the following steps: under the protection of inert gas, mixing raw materials, a catalyst, lignin and an auxiliary agent according to a ratio, carrying out an esterification reaction to generate an oligomer, then carrying out a pre-polycondensation reaction under a vacuum condition, and then carrying out a final polycondensation reaction to obtain the intrinsic anti-ultraviolet aging bio-based polyester elastomer. The intrinsic anti-ultraviolet aging bio-based polyester elastomer is obtained. The bio-based polyester with high molecular weight and low melt index is prepared by utilizing a polyhydroxy structure of lignin, and the phenolic hydroxyl structure rich in lignin is utilized to provide ultraviolet aging resistance and other properties of the material, so that the problems of precipitation, poor compatibility and non-uniform dispersion of an ultraviolet aging resistant auxiliary agent after long-time use are avoided, and the 2, 4-dihydroxy-2, 4-dihydroxy-2, 4-dihydroxy-2, 4-dihydroxy-2, 4-dihydroxy-2, 4-dihydroxy-2, 4-dihydroxy-2, 4- The anti-ultraviolet aging and low melt index bio-based polyester elastomer which meets different strength and elasticity requirements and is directly prepared from 2, 5-furandicarboxylic acid, aliphatic diol, polyether glycol and lignin by a one-pot method can better adapt to market requirements, and the application field of the anti-ultraviolet aging and low melt index bio-based polyester elastomer is expanded.

The invention relates to the technical field of polymer compositions, and discloses a fiber microcrack self-healing composition with a shape memory characteristic, which comprises modified polyester containing thermally reversible dynamic covalent bonds and an asymmetric polyether-polyester block copolymer interface regulator, the melt index ratio of the interface regulating agent to the modified polyester is 1.8-3.2, and the interface regulating agent is distributed on the periphery of the modified polyester to form a core-shell microdomain. By utilizing the rheological gradient among the components, the interface regulating agent forms a low-viscosity flowing layer when the matrix shrinks; and the modified polyester is restrained to directionally migrate towards the tip of the fiber microcrack, so that active closing and densification filling of the crack area are realized, micro holes in the repaired area are eliminated, and the mechanical continuity of the composition in a dynamic environment is kept.

This invention proposes a catalyst component, catalyst, and their applications for olefin polymerization, belonging to the field of olefin polymerization technology. The catalyst component contains products obtained from the reaction of a magnesium source, a titanium source, and an internal electron donor, wherein the internal electron donor comprises furan compounds and diether compounds. The catalyst of this invention exhibits high hydrogen sensitivity and stereoregulation, with a good balance between the two. The molecular weight distribution of the prepared low melt index polymer is broader than that of the high melt index polymer, and the catalyst component of this invention does not contain phthalate compounds (plasticizers).