17 results about "Post polymerization" patented technology

Provided in the present invention are a degradable ureteral stent and a preparation method therefor, which degradable ureteral stent is of a hollow circular tube structure (1), wherein a fixing structure (2) for preventing sliding is disposed on two ends or one end of the degradable ureteral stent, the tube wall of stent is also provided with a plurality of penetrating drainage side holes (3), and the material used for the stent is a composite material formed by at least a glycolide-ε-caprolactone copolymer, an ethylene oxide polymer and a medical developer. In the glycolide-ε-caprolactone copolymer, the weight percentage content of glycolide is 51-58%, such that the copolymer has appropriate mechanical strength and hardness, and the copolymer gradually becomes soft as the time of degradation increases; moreover, a certain proportion of the ethylene oxide polymer is added, and after the degradation thereof, the polymer has a lower modulus at a definite elongation and is softer and smoother, such that degraded fragments are not prone to becoming stuck and are easier to excrete from the body, and is thus more suitable for preparing a degradable ureter.

This application discloses a separator and a battery cell, relating to the field of secondary battery technology. The separator disclosed in this application includes a base layer and a coating layer located on at least one side of the base layer. The coating layer is made of a polymer, which includes primary particles and secondary particles. Before the separator comes into contact with the electrolyte, the average particle size of the primary polymer particles is A μm, and the average particle size of the secondary polymer particles is B μm. After the separator is wetted with the electrolyte, the average particle size of the primary polymer particles is C μm, and the average particle size of the secondary polymer particles is D μm. Furthermore, A, B, C, and D satisfy the following condition: 5% < (D-B) / B < (C-A) / A < 50%. The separator described in this application exhibits good electrolyte resistance and good adhesion to the electrodes.

This invention discloses a method for preparing a composite solid electrolyte and a method for preparing a battery, belonging to the field of battery technology. The method for preparing the composite solid electrolyte includes: 1. uniformly dispersing a modified oxide electrolyte with a nitride coating in a solvent; 2. dissolving lithium salt and polymer in the solvent of step 1 in a mass ratio of 1:2.5, with lithium salt first and then polymer; 3. coating the mixed solution onto a polytetrafluoroethylene mold using a coating machine and placing it in a vacuum drying oven to obtain a composite solid electrolyte membrane. The battery preparation method includes the above-described method for preparing the composite solid electrolyte. This invention can improve the interface between the battery negative electrode and the electrolyte, improve the dendrite condition of the lithium negative electrode interface, and simultaneously isolate some side reactions between the electrolyte and the negative electrode.

The present invention relates to a process for preparing an aqueous polymer dispersion with a specific post-polymerization treatment step. It further relates to an aqueous polymer dispersion and its use as a binder for a coating, a non-woven or woven substrate, an adhesive, a mortar, a putty or a sealant, in particular a waterproofing cementitious coating having low tackiness and high impermeability to water.

This invention discloses a method for preparing functional carbon materials with atomically dispersed Lewis acid-base sites, comprising: (1) polymer preparation to obtain a polymer sample; (2) polymer modification to obtain a modified polymer sample; (3) polymer carbonization: the modified polymer sample is heat-treated in a non-oxidizing atmosphere to carbonize the modified polymer sample; after carbonization, the system is naturally cooled; then, after washing and drying, the target functional carbon material is obtained. This invention utilizes atomically dispersed Lewis acidic metal sites and basic N sites to modify carbon materials in situ. The prepared functional carbon material has a large specific surface area, well-developed pore structure, abundant acid-base sites, and an atomically distributed structure, which can significantly improve the density of functional sites on the surface of the carbon material and its adsorption efficiency for boron, phosphorus, and metal impurities. Its application in the purification of chlorosilanes can greatly reduce the load of subsequent distillation and impurity removal, and improve the yield and quality of high-purity chlorosilanes.

The application discloses a continuous polymerization method of anti-gel copolyamide 56 / 6 and the anti-gel copolyamide 56 / 6, and the continuous polymerization method comprises the following steps: preparing a water solution of polyamide 56 salt by using bio-based pentanediamine and adipic acid, mixing with caprolactam and / or a prepolymer thereof, conveying to a first-stage reactor, pre-polymerizing under normal pressure to form a prepolymer, conveying to a tubular programmed temperature device for programmed temperature and pressure maintaining, then conveying to a second-stage reactor for post-polymerization reaction, obtaining a copolyamide 56 / 6 melt, and finally cooling, granulating and drying to obtain the anti-gel copolyamide 56 / 6. The polymerization process of normal pressure pre-polymerization combined with programmed temperature can reduce the cost of polymerization equipment, effectively inhibit the side reaction of pentanediamine monomer decomposition and volatilization in the preparation process, reduce the melting point through copolymerization, thereby the spinning temperature of the obtained copolymer for spinning can be reduced, the gelation in the spinning process is reduced, the melt stability of the copolymer is enhanced, and the application in the spinning field is met.

The application discloses a kettle type series continuous polymerization method and device of FEVE fluorocarbon resin, and the method comprises the following steps: continuously feeding: reaction raw materials are added into a prepolymerization kettle according to a formula proportion, the material in the prepolymerization kettle is monitored and controlled to keep in a set range, a prepolymerization reaction occurs, and a reaction material after the prepolymerization reaction is obtained; continuously polymerizing: the reaction material after the prepolymerization reaction sequentially passes through multiple post-polymerization kettles, a post-polymerization reaction occurs, continuous polymerization is carried out, and a FEVE fluorocarbon resin product is obtained; continuously discharging: the stable FEVE fluorocarbon resin product is collected at the outlet of the final post-polymerization kettle; and the reaction raw materials comprise fluorine-containing gas-phase monomers and hydrocarbon liquid-phase monomers, an initiator, a solvent and the like. Compared with the prior art, the application has the advantages of high automation degree, low energy consumption, good process stability and strong product quality consistency.

The present invention relates to a process for purifying a plastic feedstock to obtain a stream of purified polyolefins, comprising: a) a dissolution step by contacting the plastic feedstock with a dissolving solvent; then b) a size exclusion extraction step, employing beds of a size exclusion solid in series and fed with the polymer solution from a) at an injection point (F) and with an eluent at an injection point (S) and employing a withdrawal of an extract at a withdrawal point (E) and a withdrawal of a raffinate comprising a purified polymer solution at a withdrawal point (R), the injection and withdrawal points being distinct and offset over time by one bed according to a determined frequency; then c) a polymer-solvent separation step, to obtain a stream of purified polyolefins.The invention also relates to a device for carrying out step b) and a device for carrying out the purification process. Figure 1 to be published.

This invention belongs to the field of resin preparation technology, specifically relating to a polyphenylene sulfide resin and its preparation method. The preparation method includes the following steps: a composite stabilizer, anhydrous sodium sulfide, and a polar solvent are first mixed; the resulting first mixture undergoes a dehydration reaction to obtain a dehydrated reaction solution; the dehydrated reaction solution is then mixed with p-dichlorobenzene; the resulting second mixture undergoes prepolymerization and postpolymerization sequentially to obtain the polyphenylene sulfide resin; the composite stabilizer includes carbodiimide having the structure of formula I, lithium chloride, and sodium hydroxide; R 1 -(N=C=N) n -R 2 Equation I; n is an integer from 1 to 20; R 1 and R 2 The polymer is independently selected from substituted or unsubstituted alkyl, cycloalkyl, aryl, or aralkyl groups. The composite stabilizer in this invention effectively inhibits excessive hydrolysis by polar solvents, improves reaction efficiency, and controls the polymer molecular structure, thereby obtaining high molecular weight, high yield, and high whiteness PPS resin.

An object of the present disclosure is to provide a method for producing an aliphatic polyester resin which substantially does not contain impurities, such as metals, and which has high molecular weight, particularly a polylactic acid having high molecular weight and high optical purity. The method for producing an aliphatic polyester resin of the present disclosure has a step of contacting a solution containing a cyclic ester with a cyclic amine catalyst and a polymerization initiator to initiate a reaction, a step of conducting the reaction by flow-type polymerization, and a step of subjecting the product obtained in the flow-type polymerization to further reaction by postpolymerization by stirring.

The system provides new methods and processes for the reaction of polymeric / oligomeric substrates with reactants comprising alkyne / alkene and / or protic nucleophilic moieties to afford functionalized polymeric / oligomeric products through the utilization of homogenous and / or heterogenous gold catalysis. More specifically, the system provides routes for reaction of polymeric / oligomeric substrates comprising varying degrees of aromatic character with alkyne / alkene bearing molecules to afford a functionalized polymeric / oligomeric product. The system additionally provides pathways wherein the inverse methodology is realized, providing functionalized materials from the reaction of polymeric substrates bearing alkyne / alkene moieties with aromatic and / or protic nucleophilic reagents. Furthermore, in a tangential methodology, the system affords functionalized polymeric materials from the reaction of polymeric substrates bearing protic nucleophilic substituents with alkyne / alkene containing molecules. The system provides pathways for the facile modification of commodity polymer materials in order to produce value-added materials utilizing current polymer infrastructure, commodity polymer feedstocks, and post-consumer plastic waste.

This invention discloses a polyurea grouting adhesive for repairing concrete cracks and its application. The method first involves sequentially adsorbing phytic acid and chitosan onto the surface of magnesium hydroxide using a layer-by-layer deposition method, followed by drying and grinding to obtain a CS-PA@M composite material. Next, a dehydrated diisocyanate is prepolymerized with polyetheramine in an anhydrous environment to obtain a polyurea prepolymer. Then, dimethylthiotoluene diamine, polyetheramine, and N,N-dimethylacetamide are mixed with CS-PA@MH powder, ultrasonicated, and slowly added dropwise to the polyurea prepolymer for a post-polymerization reaction, yielding the polyurea composite material. The polyurea composite material of this invention is applied to the grouting and repair of concrete cracks. The polyurea composite material molecular chain contains abundant urea bonds and urethane groups, which can form strong hydrogen bonds with the hydroxyl groups on the cement matrix surface, significantly improving the interfacial bonding strength. This material combines high toughness, excellent impact resistance, and good adhesion properties, effectively adapting to the opening and closing movement of cracks in concrete caused by temperature changes or dynamic loads.

A process for purifying a plastic feedstock to obtain a stream of purified polyolefins, by:a) dissolution by bringing the plastic feedstock into contact with a dissolution solvent; thenb) extraction by size exclusion, implementing beds of a size exclusion solid in series and fed with the polymer solution obtained from a) at an injection point (F) and with an eluent at an injection point(S) and implementing a withdrawal of an extract at a withdrawal point (E) and a withdrawal of a raffinate including a purified polymer solution at a withdrawal point (R),the injection and withdrawal points being distinct and shifted over time by one bed according to a determined frequency; thenc) polymer-solvent separation, to obtain a stream of purified polyolefins; andfurthermore a device for performing step b) and a device for performing the purification process.

This invention discloses a dual-wavelength photoacoustic probe for ultrasound-triggered drug release monitoring and its preparation method, belonging to the field of biomedical imaging and drug delivery technology. It includes a hydrophobic polymer matrix, a drug, and FD-1080 photoacoustic sensing molecules. FD-1080 is in a monomeric state, and the probe generates a photoacoustic response in the 1040–1064 nm wavelength range. After ultrasound triggering, the polymer matrix ruptures, and FD-1080 transforms from a monomeric state to an H-aggregate state. The photoacoustic response of the probe is enhanced in the 750–780 nm wavelength range and weakened in the 1040–1064 nm wavelength range. The drug release rate is characterized by calculating the amplitude ratio of the two photoacoustic signals. This invention integrates ultrasound-controlled release, in-situ implantation delivery, and dual-wavelength ratiometric photoacoustic monitoring into a single system, reducing the influence of probe concentration on release judgment in single-wavelength detection and improving the accuracy of drug release monitoring.

This invention relates to the field of chemical synthesis technology, specifically to dental resin monomers, preparation methods, and applications. This invention synthesizes a series of novel multifunctional bile acid resins by introducing ethylene glycol oligomer spacers of varying lengths onto the bile acid backbone and linking them with methacrylamide groups. The viscosity of these resins is significantly lower than that of the commercial monomer BisGMA, and further decreases with increasing ethylene glycol chain length, overcoming the drawback of BisGMA's excessively high viscosity. Simultaneously, thanks to the multiple polymerizable groups in the molecule, the number of crosslinks formed per molecule after photopolymerization is significantly higher than that of BisGMA and UDMA. Specifically, the number of polymeric double bonds in 4MC3 and 4MC4 both exceed 2.0, an increase of at least 25% compared to BisGMA. When compounded with TEGDMA, the polymerization conversion rate can be significantly increased to a level comparable to or even higher than that of BisGMA. The resins of this invention have far better biocompatibility than BisGMA, and possess excellent handling properties and mechanical potential, making them suitable for preparing dental filling materials, dental adhesives, fissure sealants, and orthopedic repair materials.

The application discloses a system and method for large-scale industrial continuous production of PGA. In a 100,000-3,000,000 tons / year polyglycolide PGA device, glycolide raw materials and catalyst are firstly sent into a first polymerization reactor to perform adiabatic polymerization, then are sent into a second polymerization reactor to perform further polymerization, part of polymerization heat is removed through heat conduction oil in a jacket of the second polymerization reactor and a winding pipe, then the glycolide raw materials and the catalyst are sent into a third polymerization reactor to perform adiabatic polymerization, after the polymerization reaction is completed, antioxidants and deactivation agents are added to terminate the reaction, then unreacted glycolide raw materials in the polymerization product are removed through a devolatilizer, finally, the polymerization product is subjected to crystallization, granulation and packaging and stacking to obtain a polyglycolide product with a molecular weight of 156,000-212,000, a melt viscosity of 460-540 Pa·S and a tensile strength of 65-73 MPa, which can be applied to large-scale commercial continuous industrial production of polyglycolide PGA.