65results about How to "Control residue" patented technology

The invention relates to a high-efficiency environmental-friendly polypropylene compatilizer and a preparation method thereof. 60-95 polypropylene, 0.1-10 initiating agent, 1-20 maleic anhydride, 0.5-15 comonomer and 0.1-7 antidegradant are put in a high-pressure reaction vessel by weight percent (the sum of weight percent of all the raw materials is equal to 100 percent.), the solid phase grafting reaction is performed to the mixture for 0.2-2 hours under the stirring action to obtain polypropylene initiation masterbatch, then 2-30 percent by weight of polypropylene initiation masterbatch and 70-98 percent by weight of pure polypropylene are mixed in a high-speed mixer at the room temperature, then the melting graft reaction is performed to the mixture on a double-screw extruder, and then the extrusion granulation is carried out to obtain the maleic anhydride grafted polypropylene compatilizer. Compared with the prior art, the method is simple and also suitable for the industrial production, and no solvent is required to be used, therefore, no harmful toxic matter emission exists, and meanwhile, the high-efficiency environmental-friendly polypropylene compatilizer has low residual quantity of acid anhydride and odor and is beneficial to environmental protection.

The invention provides a method for controlling organic solvent residue in thymosin alpha 1PLGA microspheres. The method comprises the following steps: stirring a prepared thymosin alpha 1PLGA microsphere emulsion or multiple emulsion under normal temperature and normal pressure at a speed of 500-1200rpm for 3 hours; stirring the emulsion or multiple emulsion for 2-18 hours under the conditions of vacuum degree of -0.035MP to -0.096MP, a temperature of 26-35 DEG C and rotating speed of 50-800 rpm. The method for controlling organic solvent residue in thymosin alpha 1 microspheres provided by the invention is efficient, controllable, stable in process, safe, reasonable and capable of effectively controlling the residue problem of such organic solvents as dichloromethane and keeping the integral forms of the microspheres at the same time.

The invention discloses a preparation method of cefazolin sodium with previous research quality. The preparation method is characterized by comprising the following steps: (1) adding a boron trifluoride-dimethyl carbonate solution into dimethyl carbonate; stirring and adding 2-sulfydryl-5-methyl-1,3,4-thiadiazole and 7-ACA (Acetic Acid) to react; after the reaction is finished, adding dimethyl formamide and dropwise adding hydrochloric acid; adjusting the temperature to 25 to 35 DEG C and reacting for 60 minutes; filtering and washing with acetone; drying in vacuum to obtain a TDA (Toluene Diamine) crude product; (2) preparing mixed anhydride from dichloromethane, tetrazolyl acetic acid, triethylamine and pivaloyl chloride; (3) adding the TDA crude product into a dichloromethane solvent; cooling and dropwise adding tetramethyl guanidine; dropwise adding the mixed anhydride to react, and purifying and refining a crystal through a low-temperature acetonitrile-water extraction process after extraction and crystallization. With the adoption of the preparation method provided by the invention, the moisture content of the product can be reduced and residues of the solvent can be reduced; the increasing of related substances can be effectively reduced, a freeze-drying technology is not used and the production efficiency is improved.

The invention discloses a method for a preparing low density polypropylene foam section or beads by two-step extrusion molding, which comprises the following steps that: expandable master batch is prepared from 30 to 80 portions of polypropylene, 10 to 40 portions of foaming agent, 0 to 15 portions of foaming accelerant, 0 to15 portions of dispersant and 0 to 10 portions of nucleating agent at a temperature below the decomposition temperature of the foaming agent and above a viscous flow temperature of the polypropylene; 20 to 99 portions of polypropylene with high melt strength, 0 to 70 portions of common polypropylene and 1 to 10 portions of expandable master batch are plasticizated and extruded together; supercritical gas is added to perform the blending of the plasticizated and extruded mixture; and the product obtained is made to generate foamcores in a foaming nucleation apparatus to form the section or beads finally. A chemical foaming agent is partially decomposed and foamedduring the plasticization and extrusion, so that the viscosity of fused mass is reduced, the dissolution and dispersion of the supercritical gas are facilitated, and a problem that a foam imploding islikely to happen in a secondary forming process so as to influence the quality and appearance of secondarily formed product is solved as the chemical foaming agent retained in molding beads can be decomposed and foamed again during the secondary processing.

The invention relates to a preparation method of maleic anhydride graft polypropylene wax, which is characterized by comprising the following steps: heating and melting polypropylene wax in a kettle by using a heating system and a mixer of a reaction kettle; mixing a maleic anhydride graft monomer with the addition of 1.5 to 8.0 of polypropylene in percentage by weight by controlling the mixing rate from 120 r / min to 250 r / min at reaction temperature from 100 DEG C to 250 DEG C; adding an initiating agent with the addition of 1 / 30 to 1 / 10 of the adding quantity of maleic anhydride and a graftactive agent with the addition of 1:3 to 2:1 of the weight of the maleic anhydride at reaction time from 0.5 hour to 10 hours, thereby completing the graft reaction of the maleic anhydride; and then cooling, pelleting or crushing maleic anhydride graft polypropylene wax so as to complete the preparing process of the maleic anhydride graft polypropylene wax. The invention also discloses a relativedevice. The preparation method of maleic anhydride graft polypropylene wax has the advantages of simple and reasonable technology, easy manufacture, low production cost, simplified product formula, and the like.