971 results about "Bulk polymerization" patented technology

A method of producing cis-1,4-polydienes, the method comprising the step of contacting conjugated diene monomer with a lanthanide-based catalyst system in the presence of less than 20% by weight of organic solvent based on the total weight of monomer, organic solvent, and resulting polymer, where the lanthanide-based catalyst system is the combination of or reaction product of (a) a lanthanide compound, (b) an organoaluminum hydride, (c) a trihydrocarbylaluminum, and (d) a halogen-containing compound.

The invention discloses expandable particles for producing a polymethacrylimide foamed material and application thereof. The expandable particles are prepared by the following steps of: putting acrylic acid or methacrylic acid, acrylonitrile or methacrylonitrile, an initiator, a molecular weight regulator, a foaming agent, a foam stabilizer, a cross-linking agent and an additive into a mold; performing a primary bulk polymerization reaction at the temperature of between 30 and 50 DEG C for 10 to 72 hours; performing a further bulk polymerization reaction at the temperature of between 50 and 100 DEG C for 1 to 30 hours to obtain a copolymer plate; smashing and screening the copolymer plate to obtain the expandable particles for producing the polymethacrylimide foamed material. Pre-foamed particles can be prepared by pre-foaming the expandable particles at the temperature of between 150 and 230 DEG C for 0.1 to 2 hours, and polymethacrylimide foam particles can be prepared by foaming the pre-foamed particles at the temperature of between 190 and 260 DEG C and curing the foamed particles at the temperature of between 150 and 230 DEG C. The expandable particles expand the use range of the polymethacrylimide foamed material.

A continuous bulk polymerization and esterification process includes continuously charging into a reaction zone at least one ethylenically unsaturated acid-functional monomer and at least one linear or branched chain alkanol having greater than 11 carbon atoms. The process includes maintaining a flow rate through the reaction zone sufficient to provide an average residence time of less than 60 minutes and maintaining a temperature in the reaction zone sufficient to produce a polymeric product incorporating at least some of the alkanol as an ester of the polymerized ethylenically unsaturated acid-functional monomer. The polymeric product is used in various processes to produce water-based compositions including emulsions and dispersions such as oil emulsions, wax dispersions, pigment dispersions, surfactants and coatings which contain the polymeric product. A polymeric surfactant includes at least one ethylenically unsaturated acid-functional monomer which has been radically incorporated into the polymeric surfactant and at least one ester of the incorporated ethylenically unsaturated acid-functional monomer which has a linear or branched chain alkyl group with greater than 11 carbon atoms. The molar critical micelle concentration of the polymeric surfactant is less than 1.0×10−2 moles / liter. Aqueous 2 percent solutions of certain polymeric surfactants have a surface tension of less than 45 mN / m at 30° C. and exhibit a decrease in surface tension of at least 5 mN / m as the temperature warms from 30° C. to 50° C.

The invention relates to a process for preparing reabsorbable polyesters by bulk polymerisation, wherein the reaction components are melted and homogenised in a stirred reactor, the reaction mixture is then transferred into a number of smaller-volume containers, the reaction mixture is polymerised in these containers and the polyester obtained is isolated by removing it from the containers, and the use of the reabsorbable polyesters thus produced for preparing reabsorbable implants.

The process of producing polyurethane elastomer with the material including one component A of polyether glycol and / or polyester polyol, one component B of organic diisocyanate and one component C of small molecular diol as the chain expanding agent, includes the following steps: melting the components while adding organic tin catalyst in 0.001-0.05 wt% to the component A, metering precisely with one metering system, and mixing and bulk polymerizing in a double screw extruder with precise temperature control system at 180-260 deg.c for 3-15 min to obtain the polyurethane elastomer. The polyurethane elastomer is applied in melt spinning to produce elastic polyurethane fiber. The production process is simple, easy in control and low in cost, and elastic polyurethane fiber produced with the polyurethane elastomer has high quality.

The present invention relates to a preparation method for high performance water reducer made from high water reducing solid polycarboxylic acid. The prepartion method specifically comprises the following steps: performing heat fusion on two unsaturated polyoxyethylene ether composite macromonomers with different molecular weights; then dropwise adding a mixed liquid of an unsaturated carboxylic micromonomer, an unsaturated amide micromonomer and a chain transfer agent under the reaction of an initiator; and preparing the water reducer through a free radical polymerization reaction, and after the reaction, using a neutralizing agent to adjust a pH value to 5-6 and then cooling and grinding the water reducer in a solid particulate shape. The preparation method provided by the present invention has advantages of being simple in process, high in conversion rate and environmental-friendly and free of pollution, and has the characteristics of high water reduction and low adulterate amount in concrete and dry-mixed mortar, and the transportation cost in long distance transportation is greatly lowered.

The invention provides a method for preparing viscosity-reducing polycarboxylate superplasticizer. The viscosity-reducing polycarboxylate superplasticizer is prepared through a bulk polymerization reaction, and the method comprises the following steps of: (1) mixing polyoxyethylene polyoxypropylene ether and polyoxyethylene ether, controlling the temperature at 40-60 DEG C, stirring the mixture evenly, and then adding an initiator and a mixture of unsaturated carboxylic acids, hydroxyalkyl unsaturated carboxylate and a chain transfer agent; and (2) performing aging for 1-1.5 hours after the step (1) is completed, and reducing the temperature to obtain the viscosity-reducing polycarboxylate superplasticizer. Since the bulk polymerization reaction is carried out at a low temperature, the method has strong operability, mild conditions and low energy consumption; the viscosity-reducing polycarboxylate superplasticizer prepared by using the method is at a liquid state at room temperature, has effective concentration of 100% and stable storage performance, and is suitable for long-distance transportation and use; meanwhile, the viscosity of a concrete mixture can be reduced effectively through the superplasticizer so that stirring, transportation and pumping of concrete can be facilitated, and the superplasticizer is suitable for the promotion and application of high-rise engineeringand high-performance concrete.

The invention discloses an industrial production method of high isotactic polybutylene and a device for implementing the method. The production method comprises the process flows of carrying out bulk polymerization on a liquid-phase butylene-1 monomer in a polymerization kettle at the temperature of 10 DEG C below zero to 70 DEG C above zero to synthesize isotactic polybutylene, and recovering part of unreacted butylene-1 into a butylene gasometer through primary pressure reduction after polymerizing for a certain period of time; then, transferring high isotactic polybutylene from the polymerization kettle to a flash distillation kettle, carrying out reduced-pressure flash distillation, and further recovering the unreacted butylene-1 monomer into the butylene gasometer; sequentially introducing nitrogen gas and air into the flash distillation kettle to replace, discharging a granular high isotactic polybutylene product through an emptying valve at the bottom of the kettle, and packaging. The device comprises a proportioning system, a polymerization system, a gas distribution system, a vacuum nitrogen system, a degassing and flash distillation system and a utility system. Through the industrial production method and the device, the industrial synthesis of the high isotactic polybutylene can be realized, and no organic solvents, waste gases, waste water and waste residues are discharged; in addition, the industrial production method belongs to a green and clean production process.