65results about How to "Play a role in heterogeneous nucleation" patented technology

The invention provides a polyacetal resin composition. The polyacetal resin composition comprises 100 parts of polyacetal resin, 0.001-2.0 parts of an antioxidant, 0.005-3.0 parts of a formaldehyde absorbent, 0.002-2.0 parts of an acid absorbent, 0.001-2.0 parts of a processing stabilizer and 0.1-20 parts of a modified inorganic filler, wherein the modified inorganic filler is obtained by using a modifying agent for modifying an inorganic filler at a rotating speed of 3000-50000r / pm at the temperature of 60-200 DEG C. The modified inorganic filler can be ensured for improving the compatibility of a composition matrix so as to realize uniform dispersion, and meanwhile plays a role in heterogeneous nucleation in the crystallization process of the composition so as to reduce the size of crystal nucleuses, thus the strength and the roughness of the obtained polyacetal resin composition are obviously improved. Experiment results show that the tensile strength of the polyacetal resin composition is 63-70MPa, and the notch impact strength of the polyacetal resin composition is 8.0-11.0KJ / m<2>.

According to the preparation method of the high-toughness heat-treatment-free material suitable for castings with various wall thicknesses, by adding Nb, B, other rare earth elements and other microelements, the nucleation mechanism of aluminum alloy is changed, the castings obtain fine and uniform metallographic structures, and therefore the overall mechanical property of the castings is improved.

The invention relates to a preparation method of organic montmorillonite (OMMT), which comprises the following step: sequentially modifying sodium-base montmorillonite with cetyl trimethylammonium bromide, epoxy resin, isophorone diisocyanate and octadecylamine to obtain the OMMT. The invention also relates to a technique for modifying a polypropylene resin by using the OMMT, which comprises the following steps: 1) preparing the following components in percentage by weight: 0.1% of immobilized antioxidant, 0.5% of lubricant, 1-5% of OMMT and 98.4-89.4% of polypropylene; 2) adding the materials into a high-speed mixer according to the percentage by weight, and uniformly mixing; and 3) sending the uniform mixture into an extruder, and carrying out melt granulation to obtain the OMMT-modified polypropylene resin master batch. Under the heterogeneous nucleation action of the OMMT, the crystallization temperature of the polypropylene is enhanced. Due to the nano effect, the polypropylene is toughened and reinforced; and the OMMT and polypropylene macromolecular chain have strong interfacial action, thereby enhancing the tensile strength of the polypropylene.

The invention provides a novel non-rare earth cast magnesium alloy. The alloy is an Mg-Bi-Zr-Zn alloy and comprises the following components by weight percent: 0.5-8wt% of Bi, 0.35-1.0wt% of Zr, 0.1-2.0wt% of Zn and the balance of Mg. The novel non-rare earth cast magnesium alloy has the beneficial effects that the obvious grain refinement effect of the element Zr in an Mg-Bi alloy series is found on the basis of Mg-Bi, thus improving the strength and plasticity of the alloy; the strength of the alloy is improved in an auxiliary manner by using a small quantity of the element zinc, thus developing the high-strength cast magnesium alloy from the alloy series; the yield strength is 140-155MPa; the tensile strength is 245-285MPa; and the elongation is about 6.5%.

The invention discloses an internally-plasticized antistatic polyformaldehyde material and a preparation method thereof. The polyformaldehyde material is a mixture of polyformaldehyde and ironic liquid. The preparation method comprises the following steps: respectively carrying out vacuum drying on polyformaldehyde and ironic liquid at 80-120 DEG C for 24-48 hours; adding the dried polyformaldehyde and ironic liquid into fusion mixing equipment in a mass ratio of 100 to (0.01-10), and carrying out fusion mixing at 170-200 DEG C, so as to obtain a mixture; and discharging the mixture out of the fusion mixing equipment, and cooling to the room temperature, so as to obtain the polyformaldehyde material. The polyformaldehyde material disclosed by the invention has excellent antistatic performance; by adding ironic liquid, the size of a spherocrystal of a polyformaldehyde matrix can be effectively reduced, so that a certain plasticization effect is achieved; and only common fusion mixing equipment is used in the preparation method, so that the industrial preparation is simple.

The invention relates to a method for improving the heat stability of polypropylene plastic. The method comprises the steps of (1) uniformly mixing lignin and polypropylene according to a mass ratio of (5:95)-(20:80), and performing melt blending on a mixture under the temperature of 150-250 DEG C to obtain a uniformly mixed blend; and (2) adding the blend into a material feeding hopper of a micro injection molding machine for melting under the temperature of 170-240 DEG C, injecting a mixture melt into a mold, and cooling to obtain a blended sample. The technology of the method disclosed by the invention is simple; an operating method is simple, and the cost is low; the lignin can realize a certain heterogeneous nucleation function in a polypropylene crystallization process, so that the crystallinity and the crystallization property of polypropylene can be improved; meanwhile, due to the influence of a three-dimensional meshed structure of the lignin, the heat resistance of a composite material can be improved; and the method can be popularized industrially and has a good application prospect.

Provided is a preparation method for a halloysite, ultrafine inorganic powder and PTFE micro-nano composite material, and the method relates to the technical field of preparation of PTFE micro-nano composite materials. The method comprises steps of: firstly, preparing a uniform mixing of PTFE and inorganic powder through mechanical high speed blending; then shaping the obtained mixed powder through cold pressing, and performing mold releasing to obtain a sheet-like sample; and finally placing the sample in a muffle furnace, raising the temperature to 370-380 DEG C at a rising rate of 150-200 DEG C / h, keeping the temperature for 2 hours, and then cooling the sample to the room temperature along with the furnace, thereby obtaining a PTFE micro-nano composite material. According to the method provided by the invention, the crystallization behavior of the PTFE is improved through filling with inorganic micro-nano particles; excellent mechanical properties of the PTFE are maintained by regulating interfacial adhesion between the micro-nano particles and the PTFE; meanwhile, the PTFE is endowed with excellent wear resistance and creep resistance.

The invention provides a PLA (polylactic acid)-PBC (poly(butylene carbonate)) composite material and a preparation method thereof. The PLA-PBC composite material comprises components in parts by weight as follows: 70-90 parts of PLA, 10-30 parts of PBC, 0.3-0.9 parts of Nano-TiO2 and 0.1-0.5 parts of an antioxidant. Nano-TiO2 in the composite material has a heterogeneous nucleation function so as to increase the crystallization velocity and the crystallinity of PLA and PBC, and accordingly, the PLA-PBC composite material integrating advantages of PLA and PBC is obtained.

The invention discloses a flame retardance heat aging resistant PVC (polyvinyl chloride) foaming trough plate. The flame retardance heat aging resistant PVC foaming trough plate comprises the following raw materials in parts by weight: 60-70 parts of polyvinyl chloride, 10-28 parts of nitrile rubber, 5-13 parts of chlorinated polyethylene rubber, 4-9 parts of a thermoplastic polyurethane elastomer, 5-11 parts of polyamic acid, 2-8 parts of alpha-zirconium phosphate, 5-8 parts of attapulgite, 2-7 parts of muscovite, 3-9 parts of bamboo powder, 8-17 parts of composite foaming agent, 4-11 parts of flame retardant, 0.3-1 part of an aluminum-titanium composite coupling agent, 0.3-1.2 parts of dicumyl peroxide, 0.2-1.3 parts of sulfur, 1.7 parts of an accelerant, 15-30 parts of dioctyl phthalate, 2-9 parts of chlorinated paraffin, 1-3 parts of phenyl phosphorus dichloride, 3-5 parts of resorcinol, and 2-3 parts of a composite heat stabilizer. The flame retardance heat aging resistant PVC foaming trough plate provided by the invention has good heat aging resistance, excellent flame retardance and long service life.

The invention discloses a method for reinforcing polypropylene composite material by coupling modified short carbon fiber and pyridinium-modified montmorillonite. The method comprises the following steps of putting a polypropylene plastic thin sheet, a thermoplastic elastomer and a compatilizer into an air blowing drying box to dry; uniformly mixing with the short carbon fiber treated by a silanecoupling agent, the surface-modified basalt fiber and a montmorillonite-reinforced flame-retardant system; melting, mixing and extruding at the setting processing temperature; cooling the extruded strip material, blow-drying and cutting into particles; putting the particle material into a constant-temperature drying box to dry; feeding into an injection molding machine to perform injection molding. The method has the advantages that by using the pyridinium-modified montmorillonite as a reinforcing material, and using the decabromodiphenyl ethane / antimony trioxide as a flame-retardant system, after the flame-retardant agent is added, the interlayer spacing of the montmorillonite in the polypropylene composite material is increased, and the dispersivity of the montmorillonite is improved; the thermal stability and flame-retardant property of the composite material are obviously improved, and the montmorillonite and the flame-retardant system can reach better flame-retardant synergistic effect in the polypropylene material.