53 results about "Polymer yield" patented technology

The invention provides a double metal cyanide-rare earth compound composite catalyst for CO2-epoxypropane copolymerization. In the catalyst, the mol ratio of the metal Co, Fe, Ni or Cr to La, Pr, Nd, Yb, Lu or Y of rare earth is 1:1-1:16. When the catalyst is used for the CO2-epoxypropane copolymerization, the weight content of cyclic carbonate ester in a reaction mixture is less than 2 percent, the polymer yield in a crude product is improved by more than 30 percent compared with the condition that only the double metal cyanide is used as the catalyst, and the maximum catalysis efficiency can reach 52kg of polymer in 1g of compound DMC (Dimethyl Carbonate). In the copolymer, the content of carbonic ester is more than 35 percent, and the content of Mn is more than 100,000g / mol.

Tertiary amine catalysts having isocyanate reactive groups capable of forming thermally stable covalent bonds able to withstand temperatures from 120° C. and higher and up to 250° C. are disclosed. These catalyst can be used to produce polyurethane foam having the following desirable characteristics: a) very low chemical emissions over a wide range of environmental conditions and isocyanate indexes (e.g., indexes as low as 65 but higher than 60); b) sufficient hydrolytic stability to maintain the catalyst covalently bound to foam without leaching of tertiary amine catalyst when foam is exposed to water or aqueous solutions even at temperatures higher than ambient (temperature range 25° C. to 90° C.); and c) stable contact interface between the polyurethane polymer and other polymers (for example polycarbonate) with minimal migration of tertiary amine catalyst from polyurethane polymer to other polymers yielding no noticeable polymer deterioration at the point of contact even under conditions of heat and humidity.

The invention discloses an amphiphilic polymeric micro-spherical material uniform in grain size, a preparation method and an application and belongs to the field of high molecular materials and solvesthe problems that an existing preparation method is hard to regulate grain size, low in polymer yield, poor in application effect and the like. The preparation method comprises the following steps: by taking N-vinyl pyrrolidone and divinylbenzene as a monomer, dispersing an emulsion uniformly in a water phase by a certain way; strengthening affiliation of the hydrophobic monomer divinylbenzene and the hydrophilic monomer N-vinyl pyrrolidone to increase the yield by means of proper water phase composition and proportion; and carrying out polymerization in conditions of a strict temperature androtating speed and the like to finally obtain the amphiphilic polymeric resin material uniform in grain size. Through serial representation and application evaluation, the material has very excellentamphiphilic performance, has a wide broad enriching and separating property to organic matters in a water body, and can be separately applied to the fields of analysis, detection, water treatment projects, household water purification and the like according to the grain sizes.

The invention discloses a cationic polymerization method. The method comprises the following steps that on the solution polymerization condition, monoolefine shown in the formula II and conjugated diene shown in the formula II make contact with components in an initiator system in a polymerization solvent, the initiator system contains compounds capable of providing carbocation, lewis acid and an activating agent, the activating agent is selected from a compound shown in the formula I-1 and a compound shown in the formula I-2. Compared with a simple C+ / lewis acid initiator system, the initiating efficiency of the method is remarkably improved, and the higher polymer yield can be obtained at the higher polymerization rate; polymers of different molecular weights can be obtained on different polymerization conditions by adjusting the content and varieties of the activating agent in the initiator system; in addition, the method can perform polymerization under the higher temperature, and energy consumption in the polymerization reaction process is effectively lowered.

Tertiary amine catalysts having isocyanate reactive groups that are capable of forming thermally stable covalent bonds able to withstand temperatures up to 120° C. are disclosed. These catalyst can be used to produce polyurethane foam having the following desirable characteristics: a) very low chemical emissions over a wide range of environmental conditions and isocyanate indexes (e.g. indexes as low as 65 but higher than 60) while meeting all physical property requirements; b) sufficient hydrolytic stability to maintain the catalyst covalently bound to foam without leaching of tertiary amine catalyst when foam is exposed to water or aqueous solutions even at temperatures higher than ambient (temperature range 25° C. to 90° C.); and c) stable contact interface between the polyurethane polymer and other polymers (for example polycarbonate) with minimal migration of tertiary amine catalyst from polyurethane polymer to other polymers yielding no noticeable polymer deterioration at the point of contact even under conditions of heat and humidity.

The invention discloses a preparation method of a halogenated monoolefine-alkyl styrol copolymer. The preparation method comprises the steps that monoolefine shown in the formula II and alkyl styrol shown in the formula III make contact with components in an initiator system in alkane under the condition of cationic polymerization, and the obtained solution containing the halogenated monoolefine-alkyl styrol copolymer makes with a compound containing halogen for a halogenating reaction, and the halogenated monoolefine-alkyl styrol copolymer is obtained, wherein the initiator system contains a compound capable of providing protons, lewis acid and an activating agent, and the activating agent is selected from the compound shown in the formula I-1 and the compound shown in the formula I-2. By means of the method, polymerization efficiency can be obviously improved, the higher polymer yield is obtained, the polymer with high molecular weight can be obtained, the solvent replacement process and the polymer redissolution process needed in a slurry polymerization are omitted, and the production process is simplified.