104 results about "Environmental stress cracking" patented technology

The utility model relates to a PE (Poly Ethylene) water supply reinforced pipe which comprises an inner layer, a middle layer and an outer layer, the inner layer and the outer layer are made of high-density polyethylene resin, the middle layer is a hole net pipe steel framework, and the hole net pipe steel framework is adhered with the high-density polyethylene resin of the inner layer and the outer layer through hot melt adhesive. According to the PE water supply reinforced pipe, the steel-plastic composite technology is adopted, the PE plastic pipe is improved from the product structure, the problem that the wall thickness is not uniform is solved, and nearly half of raw materials are saved. The product has high compressive strength and creep resistance, good ring stiffness and impact resistance, low linear expansion coefficient and heat conductivity coefficient, good weldability, environmental stress cracking resistance and rapid cracking resistance, and is convenient to construct, simple in welding process and low in engineering comprehensive cost.

The invention provides a peroxide crosslinked polyethylene pipe as well as a preparation method and a preparation system thereof, and belongs to the technical field of polyethylene pipes. According to the peroxide crosslinked polyethylene pipe disclosed by the invention, the high-density polyethylene and the ultra-low-density polyethylene are adopted, and the antioxidant and the lubricant are combined, so that the heat resistance, the flexibility, the creep resistance, the environmental stress cracking resistance, the radiation resistance and the oxidation resistance of the peroxide crosslinked polyethylene pipe are improved; meanwhile, a polymer containing boric acid ester bonds is added into the assistant crosslinking agent, so that the crosslinking uniformity, radiation resistance, heat resistance, durability, aging resistance and mechanical properties of the peroxide polyethylene pipe are improved.

The invention discloses a controllable micro-crosslinking modified high-impact high-density polyethylene composite material and a preparation method thereof. The composite material comprises high-density polyethylene resin, a one-dimensional nano material / maleic anhydride grafted polyethylene master batch, a redox cross-linking agent and a cross-linking assistant. The one-dimensional nano-material serves as a stress concentration point in the matrix and plays a role in absorbing a large amount of energy, so that the impact resistance of the material is improved; the controllability of micro-crosslinking is realized through the synergistic effect of an oxidation-reduction crosslinking agent and tetramethylthiuram disulfide, and the impact resistance of the material is further improved through a long-chain branch and a three-dimensional network structure formed by micro-crosslinking; and the crystallinity of the composite material is reduced, so that the impact resistance of the material is obviously improved. Besides, the melt strength and the environmental stress cracking resistance of the material are greatly improved through controllable micro-crosslinking modification, so that the applicability of the high-density polyethylene in the fields of large-volume injection molding parts, large-diameter pipes and the like is enhanced, and the application field of the high-density polyethylene is widened.

The utility model discloses a low-temperature anti-cracking novel flexible cable, which comprises at least three groups of conductors, each conductor comprises a plurality of twisted flexible round copper wires, the outer wall of each conductor is coated with an insulating layer, the conductors and the insulating layers form a cable core, the outer wall of the cable core is provided with a filling layer, the outer wall of the filling layer is lapped with a lapped layer in an overlapping manner, and the lapped layer is provided with an insulating layer. The outer wall of the wrapping layer is wrapped by a shielding layer formed by weaving copper wires, the outer wall of the shielding layer is wrapped by a lining layer, the outer wall of the lining layer is provided with an armor layer formed by tightly winding low-carbon steel wires, the outer wall of the armor layer is wrapped by a flame-retardant layer, and the outer wall of the flame-retardant layer is wrapped by an outer protective layer. Soft round copper wires are selected as conductors, so that the stability of electric energy transmission of the cable is improved while the overall flexibility of the cable is guaranteed; irradiation crosslinked polyethylene is adopted for insulation, so that the excellent electrical insulation performance, wear resistance, impact resistance, environmental stress cracking resistance and the like of crosslinked polyethylene are reserved, and the defect that during traditional silane steam crosslinking, steam immerses into the insulation to accelerate oxidation of a conductor is overcome.

The invention relates to the field of coatings, and discloses a polyethylene powder coating suitable for ship seawater pipelines and a preparation process thereof, and the preparation process comprises the following steps: step (1): preparing the following components in percentage by mass: 32%-34% of low density polyethylene, 30%-34% of toughened polyethylene, 12%-16% of an environmental stress cracking resistant polymer, 13%-17% of an adhesive, 1%-3% of a curing agent and 1%-3% of a curing agent; the component A comprises the following components in percentage by weight: 0.5%-1.5% of epoxy resin, 4.5%-5.5% of pigment filler, 0.2%-0.4% of slipping agent, 1.0%-1.8% of anti-aging agent and 0.2%-0.4% (2) weighing and proportioning the components in the step (1), and fully mixing the proportioned components for 5-10 minutes to ensure that the components are uniformly dispersed; according to the marine pipeline environment, the marine pipeline has excellent corrosion resistance and environmental stress cracking resistance and can effectively resist chemical corrosion and mechanical stress under seawater and changeable climate conditions, and the service life of the pipeline is remarkably prolonged. In the formula, the toughened polyethylene and the environmental stress cracking resistant polymer are reasonably combined, so that the toughness and the cracking resistance of the coating are improved, and the coating is prevented from being damaged due to temperature change and mechanical vibration.

The invention provides a special material for a large hollow container and a preparation method thereof, the special material is prepared by adopting a kettle type slurry polymerization process with three kettles connected in series, a catalyst, ethylene and hydrogen are added into a first reaction kettle, and a low-molecular-weight homopolymer is formed; adding ethylene, alpha-olefin and hydrogen into a second reaction kettle to form a high molecular weight copolymer; adding ethylene, hydrogen and alpha-olefin into a third reaction kettle to form a medium molecular weight copolymer; and performing post-treatment on the medium-molecular-weight copolymer to obtain the special material for the large hollow container. The structural composition of the product is optimized by designing the molecular weight and proportion of each kettle product in a three-kettle series connection process, so that the processability and mechanical property of the product are improved, and compared with the prior art, the processability and environmental stress cracking resistance of the resin are remarkably improved.

The invention relates to an alumina fiber-containing cable outer sheath material with an electromagnetic shielding function, and belongs to the technical field of cable preparation. The cable outer sheath material comprises the following raw materials: linear low-density polyethylene, electromagnetic shielding microspheres wrapped by alumina fibers, an aluminate coupling agent, an ethylene-vinyl acetate copolymer, an antioxidant 1076 and a polyolefin elastomer POE, the electromagnetic shielding microspheres wrapped by alumina fibers are introduced, and the electromagnetic shielding microspheres wrapped by alumina fibers are coated by a plurality of layers of metal coatings and alumina. The electromagnetic shielding performance of the outer sheath of the cable is further improved; in addition, the linear low-density polyethylene provides basic flexibility and environmental stress cracking resistance, the ethylene-vinyl acetate copolymer dispersive substance improves the cohesiveness and impact resistance of the material at the same time, and the polyolefin elastomer can enhance the low-temperature toughness and prolong the bending fatigue life; the components cooperate to meet the application requirements, and meanwhile, the cable outer sheath material with a good electromagnetic shielding effect is provided.

The present invention belongs to the field of polypropylene materials, and specifically discloses a polypropylene composition, a preparation method and an application thereof. The polypropylene composition of the present invention comprises the following components in parts by weight: 55-80 parts of polypropylene resin, 10-20 parts of long-chain branched low-density polyethylene resin, 5-15 parts of filler, 2-10 parts of compatibilizer, and 1-5 parts of processing aid. The polypropylene composition system of the present invention has good compatibility, which not only makes the polypropylene composition have strong environmental stress cracking resistance, but also has excellent mechanical properties.

The invention provides a processing device for preventing stress cracking of a fluorinated ethylene propylene cable material, which is characterized in that a raw material mixing tank (1) is communicated with a closed condensation barrel (2) and a reaction chamber (5), a first stirrer (6) and a heating device (7) are arranged in the reaction chamber (5), a discharge port (11) is communicated with a distillation retort (10), the distillation retort (10) is communicated with a solvent tank (14), the distillation retort (10) is communicated with a second stirrer (17), and the second stirrer (17) is communicated with the solvent tank (14). A second stirrer (17) is communicated with a collecting tank (19) after passing through a rinsing bath (18), a perfluoroalkyl vinyl ether modified fluorinated ethylene propylene cable material emulsion is used as a base material, a homogeneous system is formed by utilizing the characteristic that hexafluoroisopropanol can be mixed and dissolved with water and can also be dissolved with organic compounds, heat treatment under pressure is carried out, hexafluoroisopropanol is recovered through distillation, and then the emulsion is condensed. According to the fluorinated ethylene propylene resin cable material prepared by the invention, the problem of internal stress defects is eliminated, and the environmental stress cracking resistance of cable products is improved.

This utility model relates to the field of composite cable technology and discloses a 0.6 / 1kV long-life heat-resistant composite cable, comprising: a main control insulation wire, an outer sheath layer for the main control insulation wire, a supporting skeleton for the outer sheath layer, and multiple pressure-resistant parts for providing support capacity fixedly connected to the outer surface of the supporting skeleton. A secondary wire layer is provided on the adjacent side of any two adjacent pressure-resistant parts, and a filler protective layer is provided on the outer surface of the multiple secondary wire layers. This utility model possesses excellent high and low temperature resistance, mechanical strength, and environmental stress cracking resistance, providing comprehensive protection for the internal structure of the cable. This allows the cable to maintain stable performance under various harsh climatic conditions, further enhancing its long-life characteristics. The two direct protective layers protecting the main control insulation wire and the secondary control insulation wire, with their excellent high-temperature resistance, protect the cable's performance and slow down the aging process.

Provided in this disclosure is an ethylene interpolymer composition. The ethylene interpolymer composition includes a first ethylene interpolymer, a second ethylene interpolymer, and a third ethylene interpolymer. Further, the ethylene interpolymer composition has a density of at least 0.945 g / cm3; an environmental stress crack resistance (ESCR), measured according to ASTM D1693, Condition B, 10% IGEPAL CO-360, of at least 90 hours; and an Izod impact strength of at least 80 J / m, as measured according to ASTM D256.

A solution-phase polymerization process using a metallocene catalyst in the first reactor and a Ziegler-Natta catalyst in the second reactor yielded 0.942 g / cm³. 3 A high-density polyethylene composition is obtained having a density and a melt index I2 exceeding 5.0 g / 10 min. When prepared into plaque, the high-density polyethylene resin has an environmental stress crack resistance (ESCR) exceeding 1000 hours (determined by ASTM D1693 in 100% IGEPAL CO-630 under condition B) and an IZOD impact strength of 10 feed-pounds / inch or more. The polyethylene composition containing the first and second ethylene copolymers is relatively easy to process and can be used in the manufacture of molded articles.

The invention discloses polyethylene resin for rotational molding and a preparation method and application thereof, and belongs to the technical field of polyethylene resin. The polyethylene resin is a copolymer of ethylene and alpha-olefin; according to the polyethylene resin subjected to a continuous self-nucleation annealing thermal grading test, the content of a fraction higher than 120 DEG C is 45-55 wt%, the content of a fraction at 116-120 DEG C is 15-20 wt%, the content of a fraction at 111-115 DEG C is 10-15 wt%, the content of a fraction at 100-110 DEG C is 11-15 wt%, and the content of a fraction lower than 98.5 DEG C is 8-10 wt%. The polyethylene resin provided by the invention has excellent impact resistance, environmental stress cracking resistance and slow crack propagation resistance, and is suitable for military packaging boxes.

The present invention provides polyethylene having improved processability and resistance to environmental stress cracking as well as retaining excellent mechanical properties when combined with recycled polyethylene, and a polyethylene composition comprising same.

The invention relates to the technical field of polyethylene high polymer materials, and particularly discloses a high-strength polyethylene material for water supply engineering and a preparation method of the high-strength polyethylene material. The high-strength polyethylene material for the water supply engineering comprises the following components in parts by weight: 100 parts of high-density polyethylene, 20-30 parts of a modified ethylene-alpha olefin copolymer, 2-5 parts of an ethylene-glycidyl methacrylate copolymer, 1-2 parts of an antioxidant and 2-3 parts of a lubricant, the modified ethylene-alpha olefin copolymer is prepared by the following steps: carrying out melt blending extrusion on an ethylene-alpha olefin copolymer and a pore-foaming agent, putting a molded blend into deionized water, continuously soaking for 12-16 hours, taking out and drying. Through the synergistic effect of physical modification and chemical compatibility, the prepared polyethylene material has excellent toughness, strength and environmental stress cracking resistance, and is especially suitable for water supply pipes.

The invention relates to the technical field of submarine cables, and provides a large-diameter and large-thickness submarine cable and a cooling and conveying device, and the large-diameter and large-thickness submarine cable comprises a cable core, a cabling wrapping tape layer, a general wrapping inner protection layer, an armor layer and an outer protection layer. The cable core comprises an electric unit and an optical unit, the electric unit is provided with a conductor, the conductor is of a multi-layer structure, and semi-conductive water-blocking glue is arranged between every two adjacent layers of structures; and both the inner sheath and the outer sheath are prepared from medium-density insulating polyethylene through pressurization and extrusion. According to the submarine cable, the medium-density insulating polyethylene is adopted, so that the inner sheath and the outer sheath which are wrapped together keep relatively good structural strength and environmental stress cracking resistance for a long time, and the submarine cable is prevented from entering water or cracking; the inner protection layer and the outer protection layer are wrapped in a pressurized extrusion mode, so that the medium-density insulation polyethylene can fill gaps on the outer side of the cabling belting layer and the outer side of the armored belting layer, and the problem that the submarine cable in the prior art is poor in water resistance and cracking resistance is solved.

The invention provides a preparation method of a modified high-density polyethylene material, and relates to the field of high-density polyethylene materials. The modified high-density polyethylene material comprises 70%-85% of high-density polyethylene, 5%-15% of a flexibilizer, 3%-10% of an environmental stress cracking resistant modifier, 1%-5% of a heat stabilizer, 0.5%-2% of an antioxidant, 0.5%-3% of a nano inorganic filler and 0.5%-3% of other functional additives. By optimizing the combination of the flexibilizer, the environmental stress cracking resistance modifier, the heat stabilizer and the antioxidant, the problem that the environmental stress cracking resistance of the material is reduced due to the introduction of the modifier or filler in the prior art is effectively solved; the impact resistance and the flexibility of the material are improved.

A solution phase polymerization process employing a metallocene catalyst in a first reactor and a Ziegler-Natta catalyst in a second reactor provides a high density polyethylene composition having a density > = 0.942 g / cm3 and a melt index I2 greater than 5.0 g / 10 min. When made into a sheet, the high density polyethylene resin has an environmental stress crack resistance (ESCR) of greater than 1000 hours and an IZOD impact strength of > = 10 feet. Lbs / inch as measured by ASTM D1693 under condition B at 100% IGEPAL CO-630. A polyethylene composition comprising a first ethylene copolymer and a second ethylene copolymer is relatively easy to process and can be used to make molded articles.

The utility model discloses a degradable packaging film, which comprises a blocking layer, a heat sealing layer, a flexible surface layer and a heat sealing layer, wherein the blocking layer is clamped between the flexible surface layer and the heat sealing layer; the reinforcing layer is clamped between the tough surface layer and the barrier layer and / or between the barrier layer and the heat sealing layer; the barrier layer comprises at least one unit nylon layer, at least one unit nylon layer is a degradable nylon barrier layer, and the tough surface layer and / or the reinforcing layer are / is provided with degradable layers; the reinforcing layer comprises at least one linear low-density polyethylene layer. The barrier layer contains the degradable nylon barrier layer, and the tough surface layer and / or the reinforcing layer are / is provided with the degradable layer, so that the degradation speed and the mechanical property of different materials are flexibly adjusted, and the problem that the nylon / polyethylene barrier packaging film is not easy to degrade is solved; the strength, the toughness, the rigidity, the tear resistance and the environmental stress cracking resistance of the packaging film are improved through the reinforcing layer containing the linear low-density polyethylene layer.

This invention discloses a high-weather-resistant ABS composite material and its preparation method, belonging to the field of polymer materials technology. Addressing the problems of existing ABS materials such as easy loss of light stabilizers, poor weather resistance, susceptibility to stress cracking, and low flame retardancy, this invention provides a composite material comprising ABS resin, maleic anhydride-grafted ABS, CeO2@ZIF-8 / HALS micro / nano-release light stabilizer, and amino-terminated oligomeric polycarbonate. A three-dimensional physicochemical barrier network is constructed through micro / nano-channel slow-release technology and end-group reaction in-situ crosslinking technology. This invention significantly improves the material's long-term weather resistance and anti-loss properties, greatly enhances its resistance to environmental stress cracking, and achieves UL-94 V-0 flame retardancy and excellent anti-dripping properties without the need for additional conventional flame retardants. It is suitable for automotive exteriors, 5G base stations, and photovoltaic modules.

The present disclosure relates to a polyethylene composition capable of producing a molded product having excellent environmental stress crack resistance, and improving total volatile organic compound (TVOC) properties that can be generated by a low molecular weight polymer, and a method for preparing the same.

A solution phase polymerization process employing a metallocene catalyst in a first reactor and a Ziegler-Natta catalyst in a second reactor provides a polyethylene composition having a density > = 0.940 g / cm3 and a melt index I2 of less than 3.0 g / 10 min. The polyethylene composition has a good combination of environmental stress cracking resistance, cantilever impact strength and stiffness when made into a plate. The polyethylene composition comprising the first ethylene copolymer and the second ethylene copolymer also has a good processing window when preparing a rotationally molded sample.

The invention relates to the technical field of high polymer materials, in particular to a composite composition for rotational plastic, polyvinyl rotational plastic and application. The composite composition for the rotational molding material comprises a component A and a component B, wherein the component A comprises polyethylene resin, modified polyethylene resin, polyethylene wax and alkylphenol polyoxyethylene ether; the component B comprises a modified fiber material, an antioxidant, a flame retardant, an inorganic filler and a light stabilizer; wherein the modified polyethylene resin is polyethylene resin modified by a polysiloxane compound; the modified fiber material is a fiber material modified by organic acid or inorganic acid. The rotational plastic prepared from the composite composition for the rotational plastic provided by the invention has the mechanical properties of environmental stress cracking resistance and high impact resistance.

The invention relates to the technical field of high polymer material modification, and discloses a modified regenerated PE plastic pipeline and a preparation method thereof, and the pipeline is prepared from regenerated PE, a vinyl alcohol copolymer, an in-situ reinforcing agent composed of boric acid and tetraethoxysilane, a temperature control latent catalyst and other raw materials. The preparation method is characterized by comprising the following steps: in a double-screw extruder with a plurality of temperature zones, firstly carrying out melt blending on regenerated PE and a vinyl alcohol copolymer in a low-temperature zone to complete molecular welding; then, in a high-temperature area, through heating activation of a temperature-controlled latent catalyst, a dynamic boron ester bond network and an in-situ silicon dioxide network are synchronously initiated and constructed; through programmed sequential reaction, the technical problem of mutual interference of multiple reactions in traditional modification is solved, and a microstructure with molecule welding repair and dual-network synergistic enhancement is constructed in a regenerated PE matrix. The prepared pipeline has excellent mechanical properties, environmental stress cracking resistance and long-term hydrostatic strength.

The application relates to the technical field of high polymer material processing, and discloses a one-step granulation method for a polyethylene sheath material of an optical cable, which comprises the following steps: pre-mixing recycled high-pressure / linear low-density polyethylene film material, recycled low-pressure high-density polyethylene sheet material and an enhanced synergistic additive master batch; performing low-temperature pretreatment at 90-110 DEG C, so that low-melting-point components in the master batch are melted, and the two recycled materials with different physical forms are bonded into uniform agglomerates; feeding the agglomerates into an extruder, and performing melt extrusion granulation at 180-220 DEG C, during which interface reactivity compatibilizers in the master batch play a role. The application solves the problems of uneven feeding and poor compatibility caused by the fact that the traditional one-step method is difficult to process recycled materials with great form difference, can stably obtain a sheath material with excellent mechanical properties and environmental stress cracking resistance, and the whole process is continuous, efficient and low in cost.

The application relates to a polyethylene resin for rotational molding and a preparation method and application thereof, and belongs to the technical field of polyethylene resins. The polyethylene resin is a copolymer of ethylene and alpha-olefin; the content of a fraction greater than 120 DEG C obtained by continuously performing self-nucleation annealing thermal fractionation test on the polyethylene resin is 45-55 wt%, the content of a fraction of 116-120 DEG C is 15-20 wt%, the content of a fraction of 111-115 DEG C is 10-15 wt%, the content of a fraction of 100-110 DEG C is 11-15 wt%, and the content of a fraction less than 98.5 DEG C is 8-10 wt%. The polyethylene resin has excellent impact resistance, environmental stress cracking resistance and slow crack growth resistance, and is suitable for military packaging boxes.

The invention discloses a preparation method of an anti-corrosion water-blocking overhead insulated wire, and relates to the technical field of cables. Polyethylene, modified silicon dioxide, organic peroxide and organic tin are mixed and extruded to prepare modified polyethylene; cerium oxide, an ethylene-octylene copolymer and an ethylene-octylene segmented copolymer are used as master batch raw materials; and finally melting, extruding and coating the master batch, the modified polyethylene, the silicone rubber and the additive on the surface of the copper conductor, and curing to obtain the insulated conductor. The modified silicon dioxide participates in polyethylene cross-linking modification to form a compact network structure, so that the release of silver ions is effectively controlled, and the water blocking performance is improved; meanwhile, the ethylene-octylene copolymer and the block copolymer are compounded, so that the aging resistance and the environmental stress cracking resistance of the matrix are synergistically enhanced. The obtained conductor has excellent corrosion resistance, water resistance and aging resistance, and the service life of the overhead conductor is remarkably prolonged.

The utility model discloses a high-strength modified polyethylene anti-corrosion thermal insulation pipe, which relates to the technical field of thermal insulation pipes and comprises a working steel pipe and an outer protective pipe, the outer protective pipe is movably sleeved outside the working steel pipe, the outer wall of the working steel pipe is coated with a polyethylene anti-corrosion layer, and the outer protective pipe is sleeved outside the polyethylene anti-corrosion layer. The outer protection pipe comprises a protection sleeve layer, a high-density polyethylene protection layer and a heat preservation layer. The beneficial effects of the utility model are that: through setting the connection relation of the outer protective pipe, the protective sleeve layer, the high density polyethylene protective layer, the thermal insulation layer, the polyethylene anticorrosive layer and the working steel pipe, dust, grease, dirt and other attachments on the surface of the working steel pipe are removed through the derusting equipment, and then the derusted working steel pipe is coated; the low-temperature modified polyethylene material is creatively used, high-density polyethylene and low-density polyethylene are combined to be processed into the protective layer, and the protective layer has the strength of the high-density polyethylene and the toughness of the low-density polyethylene and has relatively high environmental stress cracking resistance time.

The application discloses a high-strength and high-toughness chemical fertilizer packaging bag and a preparation process thereof, and relates to the technical field of high polymer materials. The packaging bag prepared by the application is a five-layer co-extrusion blow molding film structure, and comprises, from outside to inside, a surface layer, a secondary surface layer, a core layer, a secondary inner layer and an inner layer in sequence, and an interface layer with rigidity and flexibility, a multi-dimensional physical cross-linking network and a dynamic reversible bond self-repairing structure are constructed, so that the problems of easy agglomeration of inorganic fillers, insufficient chemical corrosion resistance and weak interlayer adhesion are effectively improved. The packaging bag has high tensile strength, high puncture toughness and excellent environmental stress cracking resistance, and is suitable for high-strength packaging of various chemical fertilizers.

The present invention provides polyethylene having improved resistance to environmental stress cracking as well as retaining excellent mechanical properties when combined with recycled polyethylene, and a polyethylene composition comprising same.