45results about How to "Improve processing thermal stability" patented technology

The invention provides a preparation method of a PVDC composition by VDC / MA copolymerization. The preparation method comprises the following steps: putting mixing monomer, chelating agent, dispersing agent, deionized water, pH regulator, thermostability plasticizing agent and composite initiating agent into a polymeric kettle, carrying out cold dispersion on the mixture for 30 minutes, starting polymerization when raising temperature fast to 65 DEG C at the agitator speed of 120rpm, then stirring at the speed of 8rpm / h to 20rpm / h and 3 DEG C / h to 5 DEG C / h and raising the temperature to 80 DEGC to 85 DEG C at the agitator speed of 170rpm to 180rpm, finally at the agitator speed of 170rpm to 180rpm, raising the temperature to 90 DEG C at the speed of 2.5 DEG C / h to 6 DEG C / h, reacting for1h to 2h at constant temperature, stopping polymerization, separating residual monomer in vacuum, reducing temperature, discharging materials, centrifugating, drying, adding post processing auxiliaryagent, raising the temperature to 80 DEG C at the speed of 25 DEG C / h to 30 DEG C / h, mixing, curing and obtaining the composition. The PVDC composition has good forming processing thermostability andcan be used for packing low-and-medium temperature food by multi-layer coextrusion film or coextrusion casting film.

The present invention provides a highly-heat-resistant redispersible powder cellulose nano-crystal and a preparation method thereof. According to the method, cellulose is subjected to acidolysis with sulfuric acid, an ionic liquid is added to the obtained cellulose nano-crystal suspension to form the ionic bond between the ionic liquid and the cellulose nano-crystal, and the reaction liquid is dried to obtain the powder cellulose nano-crystal. According to the present invention, with the preparation method, the heat resistance and the re-dispersion in the water of the cellulose nano-crystals are effectively improved, the problem of the heat degradation during the processing of the acidic cellulose nano-crystals adopted as the nanometer filler and the matrix can be effectively solved, the production process is simplified, and the method is suitable for industrial production.

The invention discloses a PVC resin with ultra-low degree of polymerization and a manufacturing method thereof. In the invention, a polymerization method is adopted to carry out polymerization reaction, the reaction temperature is 60-64 DEG C, and the reaction pressure is less than 1.0 MPa; a first chain transfer agent is added when the polymerization reaction is carried out for 0-30min, and then0.005-0.012% of vinyl chloride monomer (VCM) is added; a second chain transfer agent is added when the polymerization reaction is carried out for 60-90min, and then 0.005-0.02% of monomer is added toobtain the PVC resin with ultra-low degree of polymerization. The PVC resin manufactured by the invention has the advantages of the average degree of polymerization below 500, high apparent density, low melting and gelatinization temperature, low melt viscosity, good transparency, short plasticization time and favorable processability and the like, and the phenomenon of accelerating products aging due to the transfer of plasticizer does not appear in machining process.

The invention provides a dull polishing sheet and manufacture process thereof. The dull polishing sheet is manufactured by the following raw materials, by weight, 100 parts of polyvinyl chloride (PVC), 1-5 parts of talcum powder, 1-3 parts of organic tin stabilizer, 3-10 parts of modifier, 0.5-1.5 parts of processing agent, 0.05-0.15 part of calcium stearate and 0.1-0.7 part of lubricant for the inside and outside. An optical haze degree and adhesive plaster sheet toughness are improved, production cost is saved, simultaneously convenience for maintaining of the device and the like is brought, device performance is improved, and productivity effect of enterprises is improved.

The invention discloses a polyolefin resin stabilizer composition, which comprises 10-80% of hindered phenol main antioxidant; 10-80% of phosphite auxiliary antioxidant; and 5-50% of acid scavenger. The stabilizer composition provided by the invention not only greatly improves the stability, and the color of the obtained product is white, but also greatly prolongs the replacement cycle of the filter net.

The invention discloses application of trisodium cyanurate to the increasing of PVC thermostability and a composite heat stabilizer containing the trisodium cyanurate. The trisodium cyanurate can be used for assisting a heat stabilizer and can increase the thermostability of PVC during processing when being combined with the heat stabilizer containing zinc during use. When the trisodium cyanurate is combined with the heat stabilizer containing zinc during use, the thermostability of the PVC during processing can be increased, product weather resistance can be increased, and 'zinc burning' can be inhibited at the same time. The composite heat stabilizer formed by the trisodium cyanurate and the heat stabilizer containing zinc keeps the advantages of nontoxicity and environment protection of the heat stabilizer containing zinc, satisfies the requirement of environment protection and is suitable for being popularized and used.

The invention provides a preparation method of a lactic and glycolic acid. The method comprises a catalyst containing three compounds of a catalytic induction system. The catalyst catalyzes and induces ring cleavage copolymerization between diglycolide and lactide to synthesize lactic and glycolic acid. The monomer to catalyst (mol ratio) is at 20,000 to 500,000 and the reaction temperature is 100 to 220 DEG C for 1 to 200 hours with inert gas protection or in vacuum. The invention has the advantages of high transformation ration, low catalyst contents of products, high molecular weight, narrow molecular weight disposition, good heat stability, small degradation of high temperature molten, good uniformity of materials, and is provided with excellent biological degradability and biologicalcompatibleness. The lactic and glycolic acid prepared by the invention can be widely used for surgical operation suture, internal fixation of fracture, tissue repair, plastic surgery, anti-organic conglutination, medical slow release, organic engineering, etc.