44results about How to "Reduced spherulite size" patented technology

The invention discloses a bimodal distribution type polypropylene foaming material and a preparing method thereof and belongs to the technical field of polymer porous materials. The technical problems of the prior art that a method for preparing a bimodal distribution type foaming material is complicated, limitation degree is high, and controllability is low are solved. The bimodal distribution type foaming material is mainly composed of porous inorganic particles and polypropylene resin, wherein the mass percent of the porous inorganic particles is 0.05-10%, particle size is 50 nanometers to 50 microns, specific surface area is 150<2> / g or above, and pore diameter is 0.3-20 nanometers. The relative density of the bimodal distribution type foaming material is 0.03-0.9 g / cm<3>, large pores with the average diameter of 15-50 microns and small pores with the average diameter of 1-10 microns are provided, and the ratio of the pore density of the large pores to the pore density of the small pores is 0.001-5:1. The bimodal distribution type foaming material has the advantages of being small in relative density and high in mechanical performance and has broad application prospects.

The invention belongs to the technical field of polymer materials, and discloses a toughened polyformaldehyde composition and a preparation method thereof. The toughened polyformaldehyde composition is prepared from the following components, by weight, 100 parts of polyformaldehyde, 0.1-0.3 part of a first nucleating agent, 0.5-2 parts of a second nucleating agent, 0.2-0.6 part of a main antioxidant, 0.2-0.6 part of an auxiliary antioxidant, 0.5-0.8 part of a formaldehyde absorber, and 3-5 parts of a lubricant. The toughened polyformaldehyde composition preparation method comprises the following steps: adding 100 parts by weight of polyformaldehyde, 0.1-0.3 part by weight of a first nucleating agent, 0.5-2 parts by weight of a second nucleating agent, 0.2-0.6 part by weight of a main antioxidant, 0.2-0.6 part by weight of an auxiliary antioxidant, 0.5-0.8 part by weight of a formaldehyde absorber, and 3-5 parts by weight of a lubricant to a high speed mixer to uniformly mix for 5-10 min, carrying out melt blending on the uniformly-mixed mixture through a vented co-rotating twin screw extruder, and carrying out extrusion granulation, wherein a screw rotation speed is controlled to 210-280 rotation / min. The toughened polyformaldehyde composition has characteristics of improved toughness, good tension strength, good rigidity and low cost.

The invention relates to a high-gloss piano black PP / PMMA alloy resin composition and a preparation method thereof. The PP / PMMA alloy resin composition comprises the following components in parts by weight: 17-40 parts of polypropylene PP resin masterbatch, polypropylene 60-75 parts of methyl methacrylate PMMA resin, 0-8 parts of toughening agent, 0.3-2.0 parts of black toner, 0.1-1.5 parts of antioxidant, 0.2-1.5 parts of weather resistance agent. The PP / PMMA alloy resin obtained by the invention has the appearance of high-gloss piano black, and meanwhile, it also takes into account the excellent scratch resistance, weather resistance and dimensional stability of PMMA, and the excellent fatigue resistance and chemical resistance of PP. The obtained PP / PMMA has a high-gloss piano black appearance, and has excellent weather resistance, scratch resistance, chemical resistance and impact resistance. It is very suitable for the selection of paint-free piano black for automotive exteriors.

The invention discloses an antistatic, friction-resistant and wear-resistant polyoxymethylene material and a preparation method thereof. The polyoxymethylene material is a mixture of polyoxymethylene, ionic liquid and polytetrafluoroethylene. Its preparation method is to vacuum-dry polyoxymethylene, ionic liquid and polytetrafluoroethylene at 80-120°C for 24-48 hours respectively; dry the polyoxymethylene, ionic liquid and polytetrafluoroethylene according to the mass ratio of 100:0.1-2 : 1-20, put into melt extrusion equipment and carry out melt extrusion at 170-200 DEG C to obtain a mixture; discharge the mixture from the melt extrusion equipment and lower to normal temperature to obtain a polyoxymethylene material. The polyoxymethylene material in the present invention has excellent antistatic performance and friction and wear resistance, and its preparation method only needs to use common melting extrusion equipment, and the industrial preparation is simple.

The invention discloses a method for preparing polyformaldehyde nascent fibers. The method includes the specific steps that polyformaldehyde resin and a small amount of o-cresol formaldehyde epoxy resin are evenly mixed and then placed into a vacuum drying box to be dried; the dried mixed materials are heated and fused in a screw extruder; spinning is carried out through a spinning assembly, spun filaments pass through a stage-by-stage slow-cooling and shock-cooling device (please see a figure in the specification) and are naturally cooled, then oil applying clustering and winding are carried out, and the nascent fibers are obtained. By means of the preparing method, the crystallinity of polyformaldehyde is effectively inhibited, the crystallization speed of the polyformaldehyde is decreased, good spinnability is given to the polyformaldehyde resin, the defects of broken filaments, surface micropores and the like generated in the multi-rate stretching process of the fibers are reduced, finished fibers obtained after the nascent fibers are stored for a period of time and then subjected to hot-air slow pulling processing are excellent in performance, the implementing method is simple, and production cost is low.

The invention discloses a high-content fiber-reinforced polyoxymethylene composite material and a preparation method thereof. The composite material comprises, by mass, 43.5-76.7wt% of acetal resin, 20.0-50.0wt% of reinforcement fibers after surface treatment, 3-5wt% of novolac, 0.2-0.5wt% of an antioxidant and 0.1-1.0wt% of a formaldehyde absorbent. The novolac is added into the composite material, the motion of polyoxymethylene molecular chains is interfered after mixing of the novolac with polyoxymethylene, the dimension of polyoxymethylene spherocrystals is obviously reduced, the degree of crystallinity is reduced, mobility and dispersity of fibers in resin are promoted, the mechanical property of the prepared high-content fiber-reinforced polyoxymethylene composite material is greatly improved; the used reinforcement fibers are subjected to surface treatment through a coupling agent and the surface modification effect is improved; and the mechanical property of the polyoxymethylene can be improved by using a novel reinforcing material of basalt fibers for reinforcing the polyoxymethylene.

The invention provides a preparation method of meltable polytetrafluoroethylene. The preparation method comprises steps as follows: (1), perfluoroalkyl vinyl ether with a general formula of Rf-O-CF=CF2 and tetrafluoroethylene have a polymerization reaction so as to provide an additive copolymer, wherein Rf represents a perfluoroalkyl group with 1-5 carbon atoms, the melt index of the additive copolymer is 0.1-0.3g / 10 min; (2), in the presence of the additive copolymer prepared in the step (1), perfluoroalkyl vinyl ether and tetrafluoroethylene which are the same as those used in the step (1) have the polymerization reaction to provide a target copolymer, and the melt index of the target copolymer is 10-50 g / 10 min.

The invention discloses a high-toughness polylactic acid composite material for environment-friendly tableware and a preparation method thereof, and relates to the technical field of polylactic acid composite materials. The high-toughness polylactic acid composite material for environment-friendly tableware disclosed in the present invention is composed of the following raw materials by mass fraction: 40-65 parts of modified polylactic acid, 35-60 parts of adipic acid-modified vegetable fibers, and 0.5-60 parts of sodium rosin 1 part, 8-15 parts of polyethylene glycol, 0.5-0.8 parts of magnesium aluminum silicate, and 2-5 parts of lubricant, the invention also discloses a preparation method of the high-toughness polylactic acid composite material for environmental protection tableware. The high-toughness polylactic acid composite material provided by the present invention has excellent impact resistance, can withstand high temperature, its thermal deformation temperature exceeds 115°C, and has excellent mechanical properties, high toughness, not easy to be brittle, and prolongs the use of The composite material is non-toxic and completely biodegradable, and can be widely used in environmental protection tableware, food packaging and other fields.