35 results about "Crystallization of polymers" patented technology

The invention discloses an on-line measuring method and apparatus for the degree of crystallization of a polymer used for injection molding. The method comprises the following steps: 1) acquiring the density of a complete crystal region of a polymer and the temperature-density curve of a complete noncrystal region of the polymer; 2) acquiring the density of a complete noncrystal region of a polymer melt in a die; 3) employing supersonic wave for real time detection of the current density of the polymer melt in the die and obtaining the real time degree of crystallization of the polymer melt according to the current density detected, the density of the complete crystal region and the density of the complete noncrystal region. The apparatus provided in the invention comprises a sensor unit, a data acquisition unit and a central processing unit, wherein, the sensor unit comprises a supersonic wave detection unit and a temperature sensor, the supersonic wave detection unit comprises a supersonic wave emitting unit and a supersonic wave receiving unit, and the temperature sensor and the supersonic wave receiving unit are respectively connected with the central processing unit through the data acquisition unit. The invention enables on-line measuring of the degree of crystallization of a polymer in the process of injection molding to be realized; the apparatus provided in the invention has the advantages of a low price and convenient usage.

The present invention relates to a polyethylene terephthalate composite material and the preparation method. The method comprises: 40 weight portion to 80 weight portion of polyethylene terephthalate, 0.1 weight portion to 4 weight portion of macromolecule nucleating agent testa liquid crystal, 1 weight portion to 6 weight portion of macromolecule crystallization accelerator, and 0.5 weight portion to 1 weight portion of other processing aids are stirred and mixed at a high speed; the mixture is then sent into a double-screw extruder through a material feeder of precise measurement. Then 10 weight portion to 50 weight portion of intensifier is filled into the double-screw extruder through the material feeder of precise measurement. The product can be prepared after plasticization, melting, compounding, and then extruding, bracing, cooling, pelletizing and drying. Compared with the prior art, the present invention has the characteristics of improving the crystallization rate of polyethylene terephthalate, widening the application scope, meeting the demands of engineering plastics for polyethylene terephthalate.

The invention discloses a method for rapid crystallization of a polymer at high temperature. The method includes the steps of (1) subjecting a polymer and an organic nucleating agent to melt blending according to a weight part at a first temperature to obtain a uniformly dispersed composition; and (2) shearing the composition at a second temperature to promote rapid crystallization of the polymer. At the second temperature, the semi-crystallization time t1/2 of the polymer material is shortened to less than 25min, thus endowing the material with excellent physical and mechanical properties and heat resistance, etc.

One embodiment of the present invention provides polymer crystalline materials containing crystals of the polymer and satisfying the following requirements (I) and (II) or the following requirements (I) and (III): (I) the polymer crystalline materials a crystallinity of 70% or greater; (II) the crystals are 300 nm or less in size; and (III) the crystals have a number density of 40 μm⁻³ or greater. This allows an embodiment of the present invention to provide polymer crystalline materials which are excellent in properties such as mechanical strength, heat tolerance, and transparency or, in particular, polymer crystalline materials, based on a general-purpose plastic such as PP, which is excellent in properties such as mechanical strength, heat tolerance, and transparency.

The invention discloses a method for predicting retention time of a gas phase chromatogram based on a macromolecule crystallization behavior derivation retention equation. The method comprises the following processes: deducing a retention equation curve which contains temperature and capacity factors based on macromolecule crystallization behavior, wherein the curve can be set up by only using three known data points which contain temperature and capacity factors of a compound at corresponding temperature; setting virtual dead time for a chromatographic column at a random temperature point according to measured retention time at a constant temperature; determining the capacity factor of the compound at the random temperature point through differentiating and integrating the whole chromatographic column according to the set retention equation curve; and predicting the retention time of the compound on the chromatographic column under a temperature-programming condition by using the data, and comparing the predicted retention time with an actually-measured value. The method for predicting the retention time of the gas phase chromatogram based on the macromolecule crystallization behavior derivation retention equation disclosed by the invention has the following advantages that: the number of adopted data points is few, and the number of experiments is reduced; the dead time has no need of measuring, and the process for predicting is simplified; and the predicting accuracy is high, and the application range is wide.

The invention relates to a method for preparing a polymer crystal, and belongs to the field of ultraviolet polymerization method. The method is characterized in that: the method comprises three polymerization reactions according to the following three directions: (1) mixing a photopolymerizable monomer and small amount of an initiator according to a certain ratio, followed by carrying out polymerization under the ultraviolet irradiation; (2) mixing two photopolymerizable monomers and small amount of an initiator according to a certain ratio, followed by carrying out polymerization under the ultraviolet irradiation through copolymerization reaction; (3) dissolving a photopolymerizable monomer in a certain amount of a solvent, followed by adding small amount of an initiator according to a certain ratio to carry out polymerization under the ultraviolet irradiation; then the prepared photopolymerizable system is placed at a low temperature less than -80-0 DEG C to enable the prepared photopolymerizable system to be converted from the transparent liquid to the crystal, then 30-80 mW/cm<2> of the ultraviolet is adopted to carry out irradiation for 1-50 minutes to obtain the polymer crystal. The method provided by the present invention is easy to be controlled, has simple steps, simple post treatment operation, and no pollution to environment.

The invention discloses a method for constructing micro-nano patterns in high-molecule film lamellas through selective dissolution. According to the method, polyoxyethylene is utilized as a raw material and is completely dissolved into an organic solvent to obtain a mixed solution; the mixed solution is spin coated to a silicon wafer to obtain a polyoxyethylene film; melting isothermal crystallization is performed on the polyoxyethylene film under a nitrogen protective atmosphere; the organic solvent is utilized to dissolve the film subjected to the isothermal crystallization; the solvent is blown and dried after the dissolution is finished, and the different patterns can be constructed in the film lamellas. The method is simple and easy to operate; the method can be applied to constructing the different structural patterns in the high-molecule lamellas, can judge stability of the inside in the lamellas through structures and can provide technical research contents of important theoretical support and the like for researching the high-molecule crystallization materials. The effects on high-molecule crystallization can be theoretically deepened, a crystallization state can be regulated in actual application, performance is optimized, materials and products with preset performance can be obtained, and very important significances are achieved.

The invention relates to a building material and a preparation method thereof, in particular to novel insulating waterproof foaming agent and a preparation method thereof. The novel insulating waterproof foaming agent comprises the following components by weight percentage of the total weight of the novel insulating waterproof foaming agent: 10 to 15 percent of rosin, 2.5 to 3.75 percent of caustic soda, 0.001 to 0.003 percent of citric acid, 0.05 to 0.1 percent of SM efficient water-reducing agent, 0.5 to 1 percent of silica powder, 35 to 47 percent of rubber powder, and 35 to 50 percent of water. The preparation method for the novel insulating waterproof foaming agent comprises the following steps: firstly mixing, stirring and heating the rosin and the caustic soda; then dissolving the SM efficient water-reducing agent, the citric acid and the silica powder into the water, heating and insulating the mixture; and mixing the two mixtures into a heating container, adding water into the mixtures and stirring the mixtures, and adding the rubber powder with required amount into the twice mixtures and stirring the mixtures. Compared with the prior art, the method adopting compound foaming improves quality of the foam greatly, the inner wall of a bubble formed by foaming can form a layer of extremely thin high-molecular crystal glue film with waterproof function, and mortar added with the foaming agent also has better heat-insulating property.

An apparatus for continuous pelletization and crystallization of a polymer includes a unit for forming a polymer pellet material and cooling the pellet material in a liquid cooling medium. An after-connected drying unit has an exit opening for exporting gas and preferably selecting air and a crystallizer for crystallizing the pellet material. The crystallizer communicates via a connection line (5) with a pre-connected unit for separating the liquid cooling medium from the pellet material and drying the pellet material. The crystallizer (6) communicates with an inert gas tank via an inlet (6a), whereby the pressure in the crystallizer can be increased relative to the pressure in the drying unit (4). In addition, A related process for continuously preparing the partially crystallized polymer particles is also disclosed.

The invention discloses a method for controlling the crystallization of polylactic acid through an alternating electromagnetic field and belongs to the technical field of polylactic acid crystallization modification. The method comprises the following steps: firstly, uniformly dispersing ferroferric oxide particles into the polylactic acid by adopting a solution blending or melt blending method, so as to obtain a polylactic acid/ferroferric oxide composite material; then putting a polylactic acid/ferroferric oxide composite material sample into the alternating electromagnetic field and carrying out heat insulation and crystallization; the movement of a polylactic acid molecular chain can be accurately controlled through controlling the frequency and strength of the alternating electromagnetic field, so that the crystallization morphology and the crystallization degree are controlled, and cannot be controlled through other methods for regulating the crystallization of the polylactic acid; furthermore, the strength of the electromagnetic field needed by the method is low and the method hopefully becomes one method which is widely used for controlling the crystallization of polymers.

The invention relates to an AIE luminescent compound and application thereof in the aspect of visual characterization of polymer crystal fluorescence. The polymer fluorescence visualization method comprises the following steps: synthesizing an aggregation-induced emission (AIE) luminophor; and dissolving the IE molecules and general polymer polylactic acid (PLLA) to form a mixture; PLLA with different crystallinity degrees is obtained through a solvent evaporation method; according to different aggregation modes of the AIE molecules in the macro-molecule crystallization area/amorphous area, different light emitting colors of the macro-molecule crystallization/amorphous area are obtained, and visualization of the macro-molecule crystallinity is achieved.

The invention relates to the field of polymer crystallization degree control, and provides a technology for controlling polymer crystallization degree in an extrusion processing process. The technology for controlling the polymer crystallization degree in the extrusion processing process comprises the following steps that a crystalline polymer is melted and extruded; the extruded crystalline polymer melt is prepared the wire rod of the polymer material through a heat medium combination, the heat medium combination comprises n sections of heat medium, wherein n is a positive integer; and the number of the heat medium passing through the melt is 1, 2, 3...and n in sequence, and the temperature of the corresponding heat medium is T1, T2, T3...and Tn. The technology heat medium for controllingthe polymer crystallization in the extrusion processing process is divided into a plurality of sections, the section number of the heat medium and the specific temperature of each section can be selected flexibly combining with the crystallization behavior, the chemical property, the cost requirement and the like of the material; then the heat history of the material after extrusion is controlled, the crystallization of the materials is promoted, and the extruded products is guaranteed to have stable and uniform crystallization.

The invention relates to a device (1) for continuous heat treatment of granulated materials, especially to the crystallization of polymer granulate, such as polyethylenterephthalate (PET) for example.The device comprises several adjacent fluidization chambers (2, 3, 4, 5, 6) respectively provided with a sieve plate (11) through which a fluidization gas used to fluidize the granulate can be insufflated into the respective chamber from below via a gas inlet (9), said gas being able to escape via a gas outlet (10) in the top area of the device. The first chamber (2) takes up the greater part ofthe overall volume of all chambers (2, 3, 4, 5, 6) and neighbouring chambers are, respectively, fluidically connected by means of product throughflow openings (18, 19, 20, 21; 28, 29, 30, 31) in the separating walls (14, 15, 16, 17) arranged therebetween. According to the inventive method, using the inventive device (1), the granulated material is guided through several adjacent fluidization chambers (2, 3, 4, 5, 6), the absolute filling level of the fluidized granulating material in the first chamber (2) being at least as high as the absolute filling level of the other adjacent chambers (3, 4, 5, 6) disposed downstream therefrom.

The invention provides a lithium battery positive plate preparation method, which comprises: (1) mixing a positive electrode active material, a conductive agent, a water-based binder and a solvent according to a certain ratio, and stirring to prepare a slurry; (2) uniformly coating the slurry on the surface of a current collector, drying, and then rolling to obtain a pole roll; (3) carrying out film rolling treatment on the pole roll; (4) carrying out slitting and slicing treatment on the pole roll to prepare a pole piece; wherein the relative humidity of one or more procedures of the steps (2)-(4) is 25%-100%. According to the invention, by controlling the environment relative humidity of one or more procedures (2)-(4) to be 25-100%, the aqueous binder in the positive plate absorbs moisture in air, so that a polymer crystal chain segment of the aqueous binder is fully stretched, the flexibility of the pole plate is improved, and the problem of brittle failure of the pole plate in the processing process is solved.

The invention provides a high-heat-preservation and aging-resistant three-layer agricultural greenhouse film and a preparation method thereof. The greenhouse film comprises an outer layer, a middle layer and an inner layer, wherein the outer layer comprises EVA(14/0.7), talcum powder, an anti-aging agent, the macromolecular crystallization modifier T-1 and the processing coordinator; the middle layer comprises EVA(5/0.3), talcum powder, an IR regulator, the macromolecular crystallization modifier T-1 and the processing coordinator; and the inner layer comprises LDPE, LLDPE, EVA(5/0.3), talcumpowder, an antifogging drop, the macromolecular crystallization modifier T-1 and the processing coordinator. The preparation method comprises the following steps: compounding the outer layer, the middle layer and the inner layer through a three-layer co-extrusion film blowing machine, carrying out extrusion, carrying out blow molding to form a film, and carrying out traction and rolling so as to obtain a greenhouse film finished product. The greenhouse film finished product can reach a photosynthetic strength of 0.88 mg * CO<2>/m<2> * S, a light transmittance of 92%, a haze of 25% and an infrared transmittance of 20%, can be continuously used for 6 months or more, and has the advantages of good heat preservation performance and fog drop antifogging property and long service life.