96results about How to "Improve low temperature brittleness" patented technology

The invention relates to the technical field of plastic product processing, particularly a RRP (polypropylene random) temperature-resistant water pipe. The RRP temperature-resistant water pipe is prepared from the following raw materials in parts by weight: 60-80 parts of carrier resin, 10-30 parts of LLDPE (linear low-density polyethylene), 1-6 parts of butyl rubber and 3-8 parts of special coloring master batch for RRP pipes. The temperature-resistant pipe has the advantages of high toughness, favorable weather resistance, wide application range and high safety, and can be used as both a cold-water pipe and a hot-water pipe.

The invention relates to a bituminous mixture using a DVS (direct vat set) high-adhesion modifier and a preparation method thereof. The bituminous mixture is prepared from aggregates, a DVS high-adhesion bituminous mixture modifier and matrix asphalt by mixing, wherein the modifier is prepared from high-desulfurization-degree reclaimed rubber, modified high-temperature coal tar pitch and a skeleton proppant by stirring and extruding. Waste rubber is deeply activated under the high temperature and high shearing action of a twin screw extruder, so that the high-desulfurization-degree reclaimed rubber is obtained; then, the mixture of the modified high-temperature coal tar pitch modified by rubber pyrolysis oil, the high-desulfurization-degree reclaimed rubber and the skeleton proppant is fully mixed by using a screw, and then extruded and granulated so as to obtain the DVS high-adhesion bituminous mixture modifier; and finally, the modifier, the aggregates and the matrix asphalt are mixed so as to obtain a DVS high-adhesion bituminous mixture. The bituminous mixture disclosed by the invention has excellent water damage resistance, good high-temperature rutting resistance and low-temperature crack resistance.

The invention discloses a casting method of a low temperature resistant iron cushion plate for a high speed railway buckling part. The method comprises smelting, spheroidizing inoculation and casting, a smelting material is made of cast iron and low-carbon steel which meets requirements that P: <=0.04% and S: <=0.03%, smelted iron water is subjected to nodulizing and inoculation and then is subjected to casting molding, and hot processing is conducted to obtain the required iron cushion plate. According to the casting method, the quantity of ferrites can be increased, the low-temperature toughness is improved, and the anti-impact performance of the iron cushion plate can be improved further.

The invention discloses an annealing process for polypropylene random copolymer (PP-R) pipes. The process includes the following steps of five times of heating treatments and cooling treatment, wherein the temperature of the first and second times of heating treatments is controlled to be lower than 100 DEG C, and the heating treatment time is controlled to be about two hours, so that the problem of pipe deformation caused by excessively high temperature and too long time is prevented; the temperature of the third and fourth times of heating treatments is controlled to be lower than 125 DEG C, the heating treatment time is controlled to be about one hour, and internal stress caused by PP-R interior molecular crystallization during pipe production is eliminated or reduced; the temperature of the fifth time of heating treatment is controlled to be lower than 100 DEG C, the heating treatment time is controlled to be about 0.5 hour, the secondary internal stress caused during annealing is avoided or reduced, the problems of pipe contraction, bending and deformation caused by too large temperature difference are reduced, the problem that low-temperature brittle cracking and the like are prone to happen to existing PP-R pipes is solved, and the production quality of the PP-R pipes is improved.

The invention provides a high strength boat deck with a low-temperature strain aging brittleness resistant property and a production method thereof. The steel comprises the following chemical components in percentage by weight: 0.04% to 0.08% of C, 0.15% to 0.45% of Si, 0.8% to 1.2% of Mn, 0.005% to 0.15% of P, not more than 0.005% of S, 0.02% to 0.08% of Al, and not more than 0.005% of N, and also comprises at least two components selected from the following components in percentage by weight: 0.05% to 0.50% of Cu, 0.05% to 0.40% of Ni, 0.02% to 0.10% of V, 0.005% to 0.05% of Nb, 0.005% to 0.05% of Ti, and 0.0005% to 0.006% of Ca. The deck base heating temperature is 1100 to 1150 DEG C, the rolling temperature in the recrystallization area is 1050 to 1100 DEG C, the finishing temperature is 880 to 940 DEG C, the accumulated deformation is not less than 60%, then the deck base is cooled in the air until the temperature of the deck base reaches 810 to 840 DEG C and then is rolled in the recrystallization area, the finishing temperature is 780 to 820 DEG C, the accumulated deformation is larger than or equal to 50%; the deck base is subjected to a laminar cooling treatment after the rolling process, the cooling speed is 8 to 15 DEG C per second, and the re-reddening temperature is 550 to 640 DEG C. The obtained high strength steel is used to manufacture ship structure, has a low strain aging sensitivity index, and can be used in an extremely cold climate.

The invention provides a polyamide polycarbonate alloy material and a preparation method and applications thereof. The polyamide polycarbonate alloy material comprises the following components in parts by weight: 5 to 90 parts of polyamide, 10 to 95 parts of polycarbonate, 1 to 15 parts of toughening agent, 1.75 to 17.5 parts of compatilizer, 15 to 55 parts of semi-aromatic polyamide fibers, and 0.2 to 2.6 parts of auxiliary agent. The preparation method comprises the following steps: evenly mixing polyamide, polycarbonate, a toughening agent, a compatibilizer, and an auxiliary agent, adding the mixture into the main feed hopper of a double-screw extruder; adding the semi-aromatic polyamide fibers into the lateral feed hopper of the double-screw extruder, and carrying out extruding, pulling, and cutting to obtain the polyamide polycarbonate alloy material. The provided polyamide polycarbonate alloy material has the advantages of good interfacial compatibility, good particle dispersing property, and high strength, can be used to prepare parts of electronic and electrical products, and has a wide application range.

The invention provides a high-temperature-resistant and wear-resistant fluororubber sealing element and a preparation method thereof. The high-temperature-resistant and wear-resistant fluororubber seal element is prepared from the following raw materials in parts by weight: 50-70 parts of 26 type fluororubber, 20-45 parts of 23 type fluororubber, 12-20 parts of medium-particle pyrolysis carbon black, 5-8.5 parts of organic modified attapulgite, 1-1.8 parts of calcium silicate, 0.5-1 part of a talc powder, 1.5-2.5 parts of hydroxyl fluorosilicone oil, 1.5-2.5 parts of magnesium oxide, 0.3-0.5 part of a silane coupling agent, 2-3 parts of perfluoromethyl phenyl hydroxyl peroxide, 0.4-0.7 part of triallyl isocyanurate, and 0.5-1 part of a processing aid. The prepared sealing element has excellent high-temperature resistance and wear resistance and high strength, and the service life of the sealing element can be effectively prolonged.

The invention discloses a toughened and modified PVC (polyvinyl chloride) plastic pipe and a preparation method thereof. The toughened and modified PVC plastic pipe is prepared from the following raw materials in parts by weight: 100 parts of PVC resin, 15 to 35 parts of high-cis butadiene rubber, 0.5 to 1.5 parts of coupling agents and 0.2 to 0.6 part of inorganic fillings. The toughened and modified PVC plastic pipe is obtained by using an extrusion forming or injection molding forming preparation process. By using a molecular structure design method, the high-cis butadiene rubber is used as toughening materials to be uniformly added into the PVC resin, so that the low-temperature brittleness of the polyvinyl chloride plastic pipe is improved, and the mechanical intensity and the heat-resistant performance are enhanced.

The invention provides an organosilicon-type polyurethane damping material and a preparation method thereof. The damping material is synthesized by methyl propylene oxide, a molecule main chain has ahomo-carbon dimethyl structure and a homo-silicon dimethyl structure, and terminal alkenyl ether alcohol is synthesized by using enol and isobutylene oxide, the diol having the homo-carbon dimethyl structure and the homo-silicon dimethyl structure is synthesized with the double-end hydrogen silicone oil having the homo-silicon dimethyl, a polyurethane prepolymer is synthesized by the raw materialand the diisocyanate, the prepolymer is reacted with a chain extender, and the organosilicon-type polyurethane damping material is obtained. The damping material prepared by the invention has good mechanical properties and damping properties, and at the same time, the low temperature brittleness, heat resistance and hydrolysis resistance of the material are improved by the introduction of the organosilicon, and the application of the material in the fields of sophisticated weapons, spaceflight aircrafts, navigation, construction, and environmental protection and the like.

The invention belongs to the field of metal material, and relates to a preparation method of a multielement alloy based on a tungsten-potassium alloy. The method comprises the following process steps: (1) in an argon atmosphere with the oxygen content of less than 0.1 ppm and the water content of less than 0.1 ppm, weighing a tungsten-potassium alloy powder, a metal X powder and grinding balls, together adding into a ball milling tank, vacuumizing the ball milling tank, then filling the ball milling tank with mixed gas of hydrogen gas and argon gas, and carrying out ball milling for 20-60 h, wherein the metal X is at least one of Ti and Y; and (2) loading the mixed powder obtained in the step (1) into a mould, then putting the mould loaded with the mixed powder into a spark plasma sintering furnace, sintering for 1-6 min under the pressure of 40-100 MPa and the temperature of 1600-1900 DEG C, then cooling to the room temperature along with the furnace, next reducing the pressure to the normal pressure, and thus obtaining the product. The multielement alloy prepared by the method has excellent irradiation resistance and thermal shock resistance.

The invention relates to modified epoxy resin and a preparation method thereof, which belong to the technical field of modified epoxy resin and solve the technical problem of utilizing furfuryl alcohol waste efficiently and achieving fine compatibility to bitumen after epoxy resin is modified. The technical scheme includes that the modified epoxy resin comprises the following raw materials: by weight parts, 3-9 parts of epoxy resin, 2-8 parts of furfuryl alcohol mud, 0.5-3 parts of polyester and 0.5-3 parts of furfuryl alcohol. Usage of the epoxy resin is reduced since part of epoxy resin is substituted, and accordingly cost is reduced. The modified epoxy resin has excellent compatibility with the bitumen, can react with the epoxy resin under a certain condition, is simple in preparation process due to the fact that most reaction is completed at the normal temperature. Cost of epoxy bitumen can be reduced and waste is utilized, energy resources are saved for the country, environment pollution is reduced and excellent social benefits are brought.

The invention discloses a PPR pipe having high ageing resistance and a manufacturing method thereof. The manufacturing method includes selecting a PPR raw material, and adding a certain quantity of zinc powder and mixing uniformly; adding a DOP liquid into the uniform mixture of the PPR and the zinc powder; putting the mixture, to which the DOP liquid is added, into a forming machine, heating to 200-230 DEG C, maintaining the temperature for 1-3 min until the mixture is prepared into a colloidal raw material; putting the colloidal raw material into a double-screw extruder, extruding and sorting granules; and then extruding a pipe and forming by using a single-screw pipe extruder. By addition of the zinc powder, a ZnO layer can be formed both on the surface and internal of the pipe, thus enhancing the ageing resistance property of the pipe, and improving the hardness and low-temperature brittleness of the pipe. The PPR pipe has a broad market prospect.