45results about How to "Control degree of aggregation" patented technology

The invention discloses a preparation method of an α-olefin polymerization catalyst, comprising the following steps: S1 carrier pretreatment: alcoholizing the carrier with organic alcohol in cyclohexane to obtain a carrier alcoholate; S2 active component loading: adding The active component titanium compound is diluted 2-4 times with cyclohexane, and then added dropwise to the carrier alcoholate for stirring to obtain the main catalyst; S3 main catalyst purification: wash the semi-finished catalyst with cyclohexane to obtain a semi-finished product containing the catalyst The slurry is dried in vacuum to obtain the purified main catalyst; S4 main catalyst reduction: the co-catalyst is used as the reducing agent, and the finished catalyst is obtained after reduction. Polymerization of alpha-olefins. The invention also discloses a catalyst prepared by the above-mentioned method, and a method for polymerizing α-olefin, which uses the catalyst prepared by the above-mentioned preparation method as the catalyst.

The invention provides a cellulosome based novel enzyme preparation cello-oligosaccharide preparation method aiming at problems of low efficiency, low yield, high cost and the like in industrial cello-oligosaccharide production in the prior art. The preparation method includes steps of raw material pretreatment, preparation of enzyme preparations, enzymolysis, aftertreatment and the like. Comparedwith an existing technique for producing cello-oligosaccharide from lignocelluloses, the method has advantages that production cost caused by high price of enzymes is reduced; in addition, due to extensive raw material sources and low cost, industrial promotion is technically supported. Further, by adoption of the method, technical problems of (1) serious feedback inhibition caused by cellobioseto cellulosome activity and (2) purification of oligosaccharide subjected to enzymolysis in adoption of cellulosome and production bacterial strains for cello-oligosaccharide preparation are solved. More importantly, compared with the prior art, the method has the advantage of high cello-oligosaccharide yield and conversion rate.

The invention discloses a method for preparing poly-3-methylthiophene coated nickel-zinc ferrite nanoparticle magnetic liquid. According to the method, nickel-zinc ferrite particles are coated with poly-3-methylthiophene by a surface in-situ synthesis method, so as to reach the effect that nickel-zinc ferrite nanoparticles are firmly wrapped by poly-3-methylthiophene; the method specifically comprises the steps of firstly preparing the nickel-zinc ferrite nanoparticles by adopting a coprecipitation method, then, preparing nickel-zinc ferrite ionic magnetic liquid from the prepared nickel-zinc ferrite nanoparticles, then, carrying out in-situ polymerization by adding 3-methylthiophene monomers and an initiator into the nickel-zinc ferrite ionic magnetic liquid so as to obtain nickel-zinc ferrite magnetic nanoparticles which are excellently coated by poly-3-methylthiophene, and finally, preparing the poly-3-methylthiophene coated nickel-zinc ferrite nanoparticle magnetic liquid from nickel-zinc ferrite / poly-3-methylthiophene composite particles.

The invention discloses an adhesive for high-density wear-resistant environment-friendly tires and a preparation method thereof. The adhesive comprises: 200-250 parts of hexamethylolmelamine, 40-50 parts of di-tert-butyl Benzothiazole, 8-10 parts of internal lubricant, 50-60 parts of film-forming compound, 15-20 parts of multibranched polymer, 4-6 parts of film-forming aid, 4-6 parts of defoamer, 3- 5 parts oily dispersing wetting agent, 2‑4 parts polymerizable emulsifier. In the preparation process of the adhesive, the present invention adds a film-forming compound and a multi-branched polymer, by adding a film-forming compound to form a film layer inside and outside on the basis of the original adhesive, the adhesive can be further improved. Excellent bond strength and aging resistance. In short, the adhesive prepared by the present invention through reasonable proportioning and multiple optimized process parameters has high bond strength, aging resistance and tear resistance, thereby improving the wear resistance and safety of tires, and the production process is green and environmentally friendly , which is of great practical significance to the development of energy conservation and emission reduction work in my country's rubber additives industry.

The invention relates to a method for fixing noble metal nano particles on a single-crystal silicon surface polymer brush, which comprises the following steps: soaking a single-crystal silicon wafer in a hydrofluoric acid solution to obtain a silicon wafer A; dropwisely adding 4-vinylbenzyl chloride onto the surface, radiating, rinsing with acetone, drying, and adding into a monomer-containing solvent; adding copper bromide or copper chloride, cuprous bromide or cuprous chloride and ligand into the solvent to carry out surface-initiated atom transfer and free radical polymerization, thus obtaining a silicon wafer C; putting the silicon wafer C in a dichloromethane solution of trifluoroacetic acid, and stirring to obtain a carboxyl-containing polymer brush; and sufficiently soaking the polymer brush in a solution containing noble metal ions, then taking out, and finally reacting in a sodium borohydride solution, thus fixing the noble metal nano particles on the single-crystal silicon surface polymer brush. The invention achieves the following technical effects: the activity is controllable in the polymerization process, the graft polymerization density is high; the polymer chain isprevented from falling off the substrate; and the controllable fixation of the noble metal nano particles is effectively implemented.