10 results about "Induction period" patented technology

A method of preparing an enhanced reactivity pozzolan may include: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and the catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.

A method of preparing an acid modified pozzolan may include: contacting a starting pozzolan with an acid to form a mixture of the starting pozzolan and the acid; reacting the mixture of starting pozzolan and the acid during an induction period to form reaction products; and recovering the acid modified pozzolan.

The invention discloses a polymerization inhibitor for rectification of carboxylic acid vinyl ester. The polymerization inhibitor is a composite polymerization inhibitor composed of a polyphenol polymerization inhibitor, a nitroxide free radical compound and an arylamine polymerization inhibitor. The composite polymerization inhibitor prepared by the invention has good solubility in a carboxylic acid vinyl ester system; the polymerization inhibition efficiency in the induction period is high, and meanwhile, the induction period is prolonged, that is, the polymerization inhibition lasting validity period of the polymerization inhibitor in a carboxylic acid vinyl ester rectification process is long.

A method of forming a rigid plastic tray suitable for oxygen-sensitive products, the method comprising the steps of mixing PET with an oxygen scavenging polymeric composition in an extruder device comprising at least one extruder screw and a melt-processing zone, wherein the PET has an antimony content of less than 46 ppm; commuting the PET and the oxygen scavenging composition through the melt-processing zone of the extruder at a temperature of from about 250 to 300° C., at a total cycle time of less than about 6 minutes and a pressure of from 0 to 900 psig, to form a melted plastic mixture; extruding the melted plastic mixture into a sheet material; thermoforming the sheet material into a rigid plastic tray.

The invention discloses a reduction-state catalyst suitable for preparing aniline through nitrobenzene gas-phase hydrogenation as well as a preparation method and application of the reduction-state catalyst, and belongs to the technical field of catalysts. The catalyst is used in a reaction for preparing aniline through nitrobenzene gas phase hydrogenation, the induction period is shorter than 3 h, the total amount of by-products in the induction period is lower than 120 ppm, and during stable operation in the induction period, phenol in an aniline product is lower than 40 ppm, and cyclohexanol in the aniline product is lower than 15 ppm; in the reduction process of the catalyst, the catalyst can tolerate rapid reduction of high-concentration hydrogen or pure hydrogen, does not influence the activity and selectivity of an induction period, has the condition that the catalyst is supplemented into a fluidized bed device in production in an oxidation state to be rapidly reduced and put into use in a high-concentration hydrogen environment in the bed, and does not influence the quality of an aniline product.

A method of preparing an enhanced reactivity pozzolan may include: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and the catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.

The application provides a self-catalytic reaction intensity grading method based on isothermal induction period characteristics. The method is based on the shape difference of the reaction curve, and first divides the self-catalytic reaction into four intensity grades according to the isothermal induction period characteristics. In the experiment, the sensitivity of the induction period characteristics of the curve to the temperature change is analyzed by carrying out isothermal tests at two or more different temperatures, so that the intensity grade of the self-catalytic reaction can be determined. In the theoretical aspect, the self-catalytic intensity grades of three classical models in different orders are determined through theoretical derivation, and for the self-catalytic reaction of a known reaction function, the corresponding self-catalytic reaction intensity grade can be quickly determined. The method can directly determine the self-catalytic intensity through the experimental curve characteristics, and can also grade from the model parameter angle, which is simple to operate, directly related to the induction period factor in risk analysis, and provides an important basis for quickly evaluating the reaction risk.

The invention discloses a PVDC (Polyvinyl Dichloride) polymerization process applying a composite initiation system, belongs to the technical field of PVDC initiators, and aims to solve the problems that the molecular weight of a PVDC product prepared by a traditional initiator is difficult to accurately control and the molecular weight distribution is wide. The process comprises the links of premixing of an initiation system, monomer pretreatment, polymerization reaction and post-treatment of a product. The initiating system is matched with the process, rapid initiating polymerization can be achieved at the temperature of 35-45 DEG C, the initiating efficiency can be remarkably improved, compared with a redox initiator in the prior art, the initiating efficiency can be improved by 60%, the induction period can be shortened to 15 minutes, meanwhile, the molecular weight can be accurately regulated and controlled to 5.2 * 10 < 4 >-1.2 * 10 < 5 >, and the molecular weight distribution index PDI is smaller than or equal to 1.8; and the residual quantity of the initiator in the finally prepared product is less than or equal to 0.01 wt%, the light transmittance of the product is more than or equal to 90%, the comprehensive performance can reach the international advanced level, and the method is suitable for production of high-end packaging materials.

This invention provides a method for controlling the polymerization induction period of large-size, complex-shaped MAX phase gel casting slurry, belonging to the field of ceramic colloidal molding technology. The method first involves calcining the MAX phase powder in air to stabilize its surface oxidation state. Then, monomers, crosslinking agents, polymerization inhibitors, dispersants, defoamers, pH adjusters, and catalysts are added to deionized water and mechanically stirred for 10 seconds to prepare a premix. Next, the MAX phase powder is added to the premix, and the casting slurry is evacuated to boiling within 30 seconds. Finally, an initiator is added to the bubble-free casting slurry, and the casting operation is completed within the polymerization induction period. This method effectively solves the problem of controlling the polymerization induction period of MAX phase gel casting slurry, resulting in large-size, complex-shaped MAX phase ceramic green bodies and sintered bodies with uniform and defect-free microstructures.

The application belongs to the technical field of semiconductor light-emitting materials, and particularly relates to a size-controllable quantum dot, a preparation method thereof and application thereof. The quantum dot is prepared by the following method: a sample in an induction period of a quantum dot pre-nucleation stage is dispersed in a solvent, and the reaction is carried out at a temperature of 25-105 DEG C for 0.5-24h. The application can accurately control the particle size of the quantum dot and further adjust the light-emitting characteristics of the quantum dot, can effectively expand the application of the quantum dot, and has a good application prospect.