6results about How to "Control molecular weight" patented technology

The invention relates to a catalytic system for preparing a cycloolefin copolymer and application. The catalytic system comprises a main catalyst, a catalyst promoter and a chain transfer agent, the main catalyst is a silane-bridged fluorenyl amino dimethyl titanium complex, a silane-bridged fluorenyl amino dimethyl zirconium complex, a silane-bridged fluorenyl amino dimethyl hafnium complex or a silane-bridged fluorenyl amino hafnium dichloride complex; the auxiliary catalyst is a silane-bridged fluorenyl amino dimethyl titanium complex, a silane-bridged fluorenyl amino dimethyl zirconium complex, a silane-bridged fluorenyl amino dimethyl hafnium complex or a silane-bridged fluorenyl amino dimethyl hafnium complex; the cocatalyst is an aluminum compound or a boron compound; the chain transfer agent is more than one of second main / subgroup metal complexes; during application, the catalytic system is adopted, and cycloolefin and non-cyclic olefin are subjected to a copolymerization reaction under the catalytic action of the catalytic system to prepare the cycloolefin copolymer. According to the catalytic system disclosed by the invention, the consumption of expensive silane-bridged metal complexes is remarkably reduced, and powerful regulation and control on the molecular weight of a polymer are realized while high polymerization activity is maintained; the prepared cycloolefin copolymer has the advantages of adjustable molecular weight wide range, narrow molecular weight distribution, and controllable cycloolefin insertion rate and glass transition temperature.

The present application relates to the field of environment-friendly materials and its preparation technology, and particularly relates to a degradable environment-friendly paper cup interior coating and a preparation method thereof. The method comprises the following steps: firstly, synthesizing polymerizable quaternary ammonium salt surfactant (RPKO-X), and then introducing the polymerizable quaternary ammonium salt surfactant and a bio-based polymer solution into a polyacrylate molecular chain by a redox initiation polymerization method, so as to obtain a degradable acrylate emulsion for paper cup interior coating. By introducing the hydrophobic monomer RPKO-X with emulsifier characteristics, a stronger crosslinking network is formed, which can significantly improve the water resistance and oil resistance of the coating. Meanwhile, by introducing the bio-based material polyvinyl alcohol 2688, the environmental friendliness of the coating is enhanced, and the rapid degradation of the coating after use is promoted. By using the redox initiation polymerization system, the method is simple to prepare, can be prepared under mild conditions, and the emulsion particle size is uniform and stable.

The present invention provides a UV-heat dual-curing electronic adhesive and a preparation method thereof, belonging to the technical field of organic polymer adhesives. The adhesive includes acrylic acid-modified epoxy resin, N,N-dimethylallylamine, methacrylic acid, glycidyl methacrylate, ethoxyethyl methacrylate, free radical photoinitiator and 2-(dodecyl trithiocarbonate)-2-methylpropionic acid; wherein methacrylic acid-modified glycidyl ether is synthesized from methacrylic acid, difunctional glycidyl ether, triphenylphosphine and inhibitor. Because its molecular chain contains carboxyl groups (participating in epoxy reaction) and tertiary amine groups (participating in catalytic thermal curing reaction) required for subsequent thermal curing reaction, the adhesive does not need to add small molecule compounds such as curing agent or catalyst during use, which reduces the pollution to electronic components at the source.

The invention discloses a phenolic aldehyde board for biomass circuit board drilling and a preparation method and application thereof.The preparation method of the phenolic aldehyde board for biomass circuit board drilling comprises the steps that cashew nut shell oil, phenol and an acid catalyst are mixed, then sodium hydroxide, paraformaldehyde and formaldehyde are added for a reaction, and a cashew nut shell oil modified phenolic aldehyde solution is prepared; diluting and impregnating wood pulp paper to prepare a pre-cured sheet; and finally, carrying out hot pressing to form the phenolic aldehyde plate. According to the biomass phenolic resin, the preparation cost of the phenolic resin can be remarkably reduced, environmental protection benefits are achieved, and the comprehensive performance of the biomass phenolic resin can be kept equivalent to that of pure phenolic resin while the permeability of a glue solution to wood pulp paper and the gluing uniformity are guaranteed.

The invention relates to the technical field of high polymer materials, in particular to intrinsic flame-retardant phenoxy amine resin and a synthesis method thereof. The resin is synthesized from polybasic primary amine, an aldehyde compound, a phosphorus-hydrogen-bond-containing compound and polyfunctional aromatic epoxy resin, n (NH2): n (aldehyde compound): n (phosphorus-hydrogen-bond-containing compound) is controlled to be 1: (1.05-2.00): 1, and the polymer resin is obtained through aldehyde-amine condensation reaction, phosphorus-hydrogen addition reaction and epoxy group ring-opening reaction chain extension. The phenoxyamine resin is mild in synthesis process condition and high in chain growth controllability, a polymer chain contains a large number of phosphorus-containing flame-retardant elements, and the phenoxyamine resin has intrinsic flame-retardant performance, achieves V-0-level flame retardance, has the limit oxygen index of 30% or above, the glass-transition temperature of 150 DEG C or above, the tensile strength of 75 MPa or above and the bending strength of 180 MPa or above. The material can be molded through a plurality of processes such as mold pressing, injection molding and solution coating, and is a novel material which is suitable for the fields of electronic packaging, rail transit, aerospace and the like and has strict requirements on flame retardance, adhesion and structural bearing capacity.

This invention relates to a method for preparing thermotropic liquid crystal polymers, in which multiple catalysts are added in combination to the polymerization system of thermotropic liquid crystal polyarylates, which greatly accelerates the polymerization reaction rate and obtains a polymer product with high storage modulus, strong mechanical properties and low dielectric constant.