39results about How to "Retain heat resistance" patented technology

The invention discloses a synthetic method for epoxy end group polythioether liquid rubber. The method comprises the following steps: synthesizing sulphydryl end group polythioether liquid rubber by using thiodiglycol, hydroxyethyl-2-hydroxypropyl thioether and the like as main monomers; then using polyethylene glycol diglycidyl ether resin as a transforming agent so as to transform a sulphydryl end group into an epoxy end group so as to finally generate the end group polythioether liquid rubber. The technology has the advantages that the polyethylene glycol diglycidyl ether resin is adopted as the transforming agent of the end group, the defects that the viscosity of a sulphydryl in traditional epoxy modification technology is high, solvents of toluene, butanone and the like are needed to perform dilution, the reaction exotherm is violent, and a side effect is easy to generate are overcome; reactions are smooth, the product quality is easy to control, the viscosity of the generated epoxy end group polythioether liquid rubber is moderate, and the stability is good; the strength of epoxy resin and the toughness and the heat resistance of polythioether rubber are reserved after the end group is transformed, so that the brittleness of the epoxy resin is improved, and the adhesive property of materials is improved.

The invention relates to a polylactic acid / polyester alloy and a preparation method thereof. The polylactic acid / polyester alloy comprises the following components in percentage by weight: polylactic acid, polyester, a compatilizer, a flexibilizer, an antioxidant and a lubricant. The preparation method comprises the following steps: firstly, proportioning the raw materials and mixing at a room temperature; and respectively carrying out melting extrusion, carrying out ultrasonic treatment at the first late stage, extruding at the second stage and pelletizing, so as to obtain degradable, high-impact-resistant and high-heat-resistant polylactic acid / polyester alloy. Compared with an existing method, the controllable ultrasonic treatment is utilized; and a similar polylactic acid-g-polyester structure is formed by in-situ reaction, so that the heat resistance of the polyester and the biodegradability of the polylactic acid are reserved; and meanwhile, a toughening system with a core-shell structure is formed in an alloy system through interface interaction of a special toughening compatilizer, so that the alloy product with high impact resistance, high heat resistance and high biodegradability can be obtained.

The invention belongs to the field of material preparation, and specifically discloses a method for preparing a multi-grain scale magnesium alloy sheet by a non-uniform section rolling method. The method for preparing the multi-grain scale magnesium alloy sheet by the non-uniform section rolling method comprises the following steps that (1), a non-uniform section sheet is formed, specifically, protrusions are formed in the surface of the formed non-uniform section sheet; (2) an annealing treatment is conducted; and (3) multiple passes of sheet rolling is conducted, specifically, a multi-grainscale sheet with uniform section is obtained through multiple passes of rolling. According to the method for preparing the multi-grain scale magnesium alloy sheet by the non-uniform section rolling method, a magnesium alloy sheet is rolled by different rolls, and a special heat treatment technology cooperates to prepare a multi-grain scale magnesium alloy sheet; and the heat resistance effect of arare earth magnesium alloy material retains while high strength and plasticity are achieved.

The invention belongs to the field of protein engineering and genetic engineering, and specifically relates to a heat-resistant xylanase XYNB with high enzyme activity at low temperature and its mutant gene, application and gene sequence preparation method. The invention provides a xylanase with high enzyme activity at low temperature Xylanase XYNB has significantly higher enzyme activity than the original enzyme at temperatures below 80°C, while retaining the heat resistance of the original enzyme. It is suitable for industrial fields such as feed additives, food, brewing, and medicine.

The invention relates to an abrasive belt, which is a zirconium corundum heavy-duty strong abrasive belt, composed of a cloth base, an adhesive, and a grinding material. The grinding material is zirconium corundum, and the grinding material is bonded to the cloth base through the adhesive. It is characterized in that: The adhesive is composed of the following components by weight percentage: 28% to 36% of first-order thermosetting phenolic resin, 4% to 8% of diphenolic propane type epoxy resin, 1% to 4% of melamine resin, and 0.2% to 0.6% of boron %, dispersant 0.1%~0.3%, coupling agent 0.1%~0.3%, diluent 3%~6%, fluoride salt 45%~60%, inert gas fluoride 0.5%~1%. The adhesive of the present invention improves the heat resistance of the abrasive belt and the bonding strength under high temperature conditions. The zirconium corundum heavy-duty strong abrasive belt of the present invention can quickly soften and reduce the hardness of the metal surface, which will neither burn the metal surface nor greatly improve the hardness of the abrasive belt. improved grinding efficiency.