11 results about "Oxidative-induction time" patented technology

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.

A polyethylene according to the present invention is characterized by having an oxidative induction time of 10 minutes or more at a temperature of 210 to 230°C when measured by a rotational rheometer, and having a peak corresponding to polypropylene when measured by NMR.

The invention discloses a method and system for evaluating the insulation aging state of a high-voltage cable, and the method comprises the steps: collecting cross-linked polyethylene insulation samples of the high-voltage cable under different operation years and different laying conditions; the insulation oxidation induction time parameters of the high-voltage cable crosslinked polyethylene insulation sample are measured according to preset test steps under laboratory conditions; calculating the measurement result by adopting a statistical method to obtain a clustering center of the high-voltage cable crosslinked polyethylene insulation sample, comparing the oxidation induction time of the to-be-evaluated high-voltage cable crosslinked polyethylene insulation with the clustering center, and evaluating the aging degree of the high-voltage cable crosslinked polyethylene insulation according to the comparison result. And the aging state of the serving high-voltage cable can be accurately evaluated.

The polyethylene of the present invention is characterized in that it has an oxidation induction time of 10 minutes or more at a temperature of 210 to 230°C as measured by a rotational rheometer, and there is a peak corresponding to polypropylene when measured by NMR.

To provide a method for producing recycled polyolefin film that can manufacture films in which oxidative degradation is suppressed without the addition of antioxidants. [Solution] The process includes manufacturing a polyolefin film by extrusion molding from pellet raw materials including virgin polyolefin pellets and non-melting recycled polyolefin pellets. A method for producing recycled polyolefin film, wherein the ratio (T2 / T1) shown in the following formula (1) is 0.8 or greater. T2 / T1···(1) [In formula (1), T1 represents the oxidation induction time measured under an oxygen atmosphere at 200°C in the state before pelletizing of non-melting recycled polyolefin pellets, and T2 represents the oxidation induction time measured under an oxygen atmosphere at 200°C for non-melting recycled polyolefin pellets.]

The invention provides a composition for high-speed production of a thin-wall polyethylene drip irrigation pipe, resin and a preparation method thereof, and belongs to the technical field of polyethylene resin. The preparation method comprises the following steps: fully mixing 60-70 parts by weight of high-density polyethylene, 10-16 parts by weight of linear low-density polyethylene, 18-25 parts by weight of low-density polyethylene, 1-3 parts by weight of carbon black masterbatch and 0.1-0.2 part by weight of an anti-ultraviolet absorbent in a high-speed mixer, granulating, and drying to prepare the resin for high-speed production of the thin-wall polyethylene drip irrigation pipe. Compared with common drip irrigation pipe resin, the resin can be produced at a high speed (more than 250m / min), the longitudinal retraction rate and the hydrostatic strength meet standard requirements after the wall thickness of a pipe is reduced to 0.12 mm, the resin has excellent rigid-tough balance, the impact strength of a simply supported beam notch is more than 80kJ / m < 2 >, the bending modulus is more than 600MPa, the tensile yield stress is more than 18MPa, the tensile fracture nominal strain is more than 800%, and the tensile strength is more than 800MPa. And the oxidation induction time is longer than 18 minutes (210 DEG C).

To provide a recycled resin composition which contains a recycled material, is hardly deteriorated in processability even when recycled, and can form a film having sufficient impact resistance and good appearance, and to provide a film, a laminate, a packaging material and a packaging bag using the same.SOLUTION: The recycled material has an oxidation-induction time of 60 minutes or more and 180 minutes or less as measured at 220 °C in an oxidizing atmosphere in accordance with JISK7351.SELECTED DRAWING: Figure 1

The present invention provides a method for producing a foam molded body, with which it is possible to suppress the formation of a carbide layer on an extruder or a head.　The present invention provides a method for producing a foam molded body, the method including a melt kneading step, a parison formation step, and a molding step. In the melt kneading step, a starting material resin composition is melt-kneaded in the presence of a foaming agent using an extruder so as to form a foaming agent-containing resin composition in a molten state. In the parison formation step, the foaming agent-containing resin composition is extruded from a head so as to form a foamed parison. In the molding step, the foamed parison is molded so as to form a foam molded body. The starting material resin composition contains a low-density polyethylene. The low-density polyethylene has an oxidation induction time of 0.5 minute or more as measured at 180°C.

The present application relates to the technical field of material performance detection, and particularly relates to a rapid test method for thermal aging failure of an oil and gas pipeline anticorrosion layer material, comprising: testing the sample for oxidation induction time t; performing thermal aging for different lengths of time at 150 DEG C, respectively, calculating A(tri) / A(mon) and a melt index change rate, establishing a linear equation of the two, and calculating A'(tri) / A'(mon) corresponding to a 35% melt index change rate; performing thermal oxygen aging on the sample for different lengths of time, calculating A(tri) / A(mon), and obtaining aging time t' according to A'(tri) / A'(mon); testing the sample for oxidation induction time to obtain a rate coefficient k; and calculating the aging time corresponding to the material failure critical point. The test method can quickly characterize the thermal aging failure critical point of the anticorrosion layer material, and provides a scientific basis for material development.

The application provides a composition, resin and preparation method thereof for high-speed production of thin-wall polyethylene drip irrigation pipe, and belongs to the technical field of polyethylene resin. The resin for high-speed production of thin-wall polyethylene drip irrigation pipe is prepared by mixing 60-70 parts of high-density polyethylene, 10-16 parts of linear low-density polyethylene, 18-25 parts of low-density polyethylene, 1-3 parts of carbon black masterbatch and 0.1-0.2 parts of ultraviolet absorption agent in a high-speed mixer, granulating and drying. Compared with common drip irrigation pipe resin, the resin can be produced at high speed (>250 m / min), and when the pipe wall thickness is reduced to 0.12 mm, the longitudinal retraction rate and static liquid pressure strength meet the standard requirements, and the resin has excellent rigidity and toughness balance, wherein the Charpy notched impact strength of the simple supported beam is >80 kJ / m 2 , the bending modulus is >600 MPa, the tensile yield stress is >18 MPa, the tensile fracture nominal strain is >800%, and the oxidation induction time is >18 min (210 DEG C).

The application discloses a recycled polypropylene multi-batch circulation processing stability repair method, and relates to the technical field of waste plastic recycling and reprocessing. The method comprises the following steps: pre-treating a plurality of recycled polypropylene batches and grouping them according to initial melt flow rates, performing a thermal residence induction test on a to-be-repaired group, detecting melt flow rates and oxidation induction times before and after thermal residence, calculating delay flow transition rates, stable reserve attenuation rates and batch instability characterization values, identifying thermal residence triggered low stable reserve batches, determining repair intensity grades according to instability degrees, adding a stability repair component, and then performing melting mixing, extrusion, cooling and granulation, and finally performing thermal residence review to determine repair eligibility. The method is beneficial to reducing the flow performance drift and discharge fluctuation risk in the continuous processing of recycled polypropylene.