44 results about "Gradient copolymers" patented technology

The invention relates to a lactide-epsilon-caprolactone copolymerization catalyst and a copolymerization method. The lactide-epsilon-caprolactone copolymerization catalyst relates to a nitrogenous bisphenol oxygen-based binuclear aluminum complex. The copolymerization method comprises the following steps of: adding lactide and epsilon-caprolactone into a reaction system sequentially or simultaneously, and carrying out copolymerization in a solvent-free system or an organic solvent medium under the catalysis of an appropriate of alcohol and nitrogenous bisphenol oxygen-based binuclear aluminum complex; and obtaining a lactide and epsilon-caprolactone copolymer through purifying after the copolymerization is finished. The high-efficiency lactide-epsilon-caprolactone copolymerization catalyst can realize synthesis of a lactide/epsilon-caprolactone segmented copolymer, a gradient copolymer, a wedge-shaped copolymer and a random copolymer. The lactide-epsilon-caprolactone copolymerization catalyst has very remarkably advantages of easily-obtained raw materials, simple polymerization method, various copolymer structures, regulating and controlling availability, higher catalysis activity and capabilities of obtaining the lactide and epsilon-caprolactone copolymer with high molecular weight and meeting requirements of the industrial department. A structural formula of the lactide-epsilon-caprolactone copolymerization catalyst is shown in a figure described in the specification.

The present invention relates to the field of tailored di-, tri- and multi-block as well as gradient polyesters/polycarbonates copolymers prepared by introducing monomers simultaneously in the reaction medium in the presence of an organometallic, metal salt or organic catalyst.

The invention relates to compositions containing two structured linear copolymers selected from the group consisting of block copolymers and gradient copolymers, said copolymers being produced according to differently controlled polymerization technologies and the difference of polydispersity of these copolymers being Delta(Mw/Mn) = 0.25. The invention also relates to the production of such mixtures and their use as wetting agents and dispersants.

The invention provides a preparation method for a polymeric nanometer microsphere. The preparation method comprises the following steps: with trithiocarbonate represented by a formula (I) as a chain transferring agent, carrying out RAFT living polymerization to synthesize a gradient copolymer; dissolving the gradient copolymer in an organic solvent and then adding water to form a polymeric micelle solution, wherein the organic solvent and water are intermiscible; and adding the polymeric micelle solution into an aqueous solution of an inorganic salt and carrying out solvent displacement so as to obtain the polymeric nanometer microsphere, wherein a volume ratio of the polymeric micelle solution to the aqueous solution of the inorganic salt is 0.01 to 1. The polymeric nanometer microsphere prepared by using the method has good stability and uniformity, narrow particle size distribution and photoresponse characteristics and the surface of the microsphere is rich in carboxyl groups, thereby facilitating application of the polymeric nanometer microsphere as a good carrier for drugs and proteins. Moreover, the method provided by the invention has the advantages of simpleness, easy practicability, good repeatability, low energy consumption, extensive applicability and easy realization of industrialization.

The invention concerns amphiphilic copolymers, in particular gradient amphiphilic copolymers obtained by controlled free radicval solution or mass polymerization. The invention also concerns a method for aqueous dissolution of said copolymers. The inventive copolymers are useful in surface treatment techniques and can be used in formulations for paints, adhesives, glues as well as in cosmetics.

The invention discloses a V-shaped gradient copolymer and a preparation process thereof. According to the copolymer and the preparation process, an emulsion polymerization system is used, a reversible addition fragmentation chain transfer free radical polymerization technology is adopted, a series of gradient copolymers in a V-shaped molecular chain structure are prepared through a step-by-step sectional charging method, and the series of gradient copolymers can serve as multi-shaped memory materials. According to the copolymer and the preparation process, devices are simple, the course is environmentally friendly and energy-saving, raw materials are cheap and easy to obtain, and the unique gradient copolymer has a good multi-shaped memory function, can serve as a high polymer material with the excellent performance and has broad application prospects in fields such as biological medicine, aerospace and mechanics and electronics.

The invention discloses a gradient function coating with surface tension changed in a gradient way, and the gradient function coating comprises the following components in percentage by weight: 5%-20% of polystyrene-b-polymethacrylic acid amphiphilic block polymers, 5%-35% of hydrophobic resin, 5%-40% of hydrophilic resin, 30%-80% of solvents, 0%-8% of pigment fillers and 0%-5% of auxiliary agents. The invention also discloses a preparation method of the gradient function coating. The gradient function coating with the surface tension changed in the gradient way, which is disclosed by the invention, is prepared under the condition that a synthetic process is simplified and the synthetic cost is reduced as far as possible by synthesizing a gradient copolymer, the hydrophilic resin and the hydrophobic resin and reasonably proportioning various coating components.

The invention relates to a preparation method of an amphiphilic gradient copolymer self-assembled in-situ composite silver nanoparticle, which is a preparation method of an in-situ composite nanoparticle taking an amphiphilic gradient copolymer as the shell and a silver nanoparticle as the core. The preparation method comprises the following specific steps: dispersing a hydrophilic silver nanoparticle in an amphiphilic gradient copolymer solution, and performing solvent induction to form the amphiphilic gradient copolymer into micelle through self assembling; and at the same time of forming the micelle, performing surface hydrophobicity modification on the silver nanoparticle with hydrophobic modifier, and ensuring that the silver nanoparticle optionally moves into the hydrophobic inner core of the polymer micelle under hydrophobic action, thus obtaining the composite nanoparticle taking the amphiphilic gradient copolymer as the shell and the silver nanoparticle as the core. The composite nanoparticle prepared by the invention is high in stability, simple in preparation process, mild in preparation conditions and easy to control, and can be used in the fields of electronics, optics and catalysts.

Provided are an acrylic hot-melt adhesive that has both good hot-melt processability and good holding power, that is suitable for applications to a hot-melt coating method in which coating is performed at a low temperature at a high speed, that has good transparency and good weather resistance, and that further has good adhesiveness at low temperatures, and a block copolymer suitable for use in the adhesive. Prepared is an adhesive containing a block copolymer having at least one structure represented by a general formula: -[A1]-[B/A2]- (where, in the formula, [A1] represents a polymer block composed of a structural unit derived from a methacrylic acid ester (A1), [B/A2] represents a copolymer block composed of a structural unit derived from an acrylic acid ester (B) and a structural unit derived from a methacrylic acid ester (A2), and the copolymer block [B/A2] has a gradient copolymer block section in which a copolymerization ratio of the methacrylic acid ester (A2) continuously increases from a section connected to the polymer block [A1]), and having a total content of the structural units derived from the methacrylic acid ester (A1) and the methacrylic acid ester (A2) of 5% to 60% by mass, a weight-average molecular weight (Mw) of 30,000 to 300,000, and a molecular weight distribution (Mw/Mn) of 1.0 to 1.5.

A hair-cosmetic composition comprising, in a cosmetically acceptable medium, at least one film-forming gradient copolymer comprising at least two different monomeric residues, and displaying a mass polydispersity index (Ip) less than or equal to 2.5, wherein the composition is able to form a film that has a strain at break epsilonr ranging from 5% to 2500%, and/or a Young's modulus ranging from 0.5 to 1200 Mpa, and/or an instantaneous elastic recovery epsiloni greater than or equal to 10%. An aerosol composition packaged in an aerosol device, comprising a propellant and a haircare composition as defined above, and also a method for treating the hair, such as a styling method, comprising applying the haircare composition or the aerosol composition above to the hair.

The invention provides a gasoline engine lubricating oil composition and a preparation method thereof. The gasoline engine lubricating oil composition is prepared from the following components: a gradient copolymer, a viscosity index modifier, a dispersant, a cleaning agent, zinc dialkyl dithiophosphate, dialkyl dithiocarbamate and/or dialkyl dithiocarbamate, an antioxidant, a friction modifier and lubricant base oil. The gasoline engine lubricating oil composition has the phosphorus content with the mass fraction being not more than 0.08%, has very excellent low-temperature performance and antioxidant performance, and can meet the requirements of SM/GF-4 and SN/GF-5 high-grade gasoline engine lubricating oil.

The invention provides a diesel engine lubricating oil composition and a preparation method thereof. The diesel engine lubricating oil composition is prepared from a gradient copolymer, a viscosity index improver, a dispersant, a clearing agent, zinc dialkyl dithiophosphate, an antioxidant and a base lubricating oil. The diesel engine lubricating oil composition has very excellent low temperatureperformance and anti-oxygen performance, and can meet the requirements of high-grade diesel engine lubricating oil at the CI-4 level or above.

A gradient copolymer comprises or consists of n polymer components. The n polymer components each independently represents an addition polymer of a monomer of the formula (I),

and/or a mixture thereof, or

the n polymer components each independently comprises or consists essential of one or more structural units represented by the formula (I-1),

The symbol n represents an integer within the closed interval [5, ∞]. The average side chain carbon number of the i-th polymer component as determined according to the nuclear magnetic resonance method is expressed as X_i, with the symbol i representing an arbitrary integer from 1 to n, the relationship X₁<X₂< . . . <X_n−1<X_n holds.

The invention discloses an open click-free radical one-pot method taking copper thioxanthone carboxylate as photocatalyst and deoxidant. The open click-free radical one-pot method comprises the following steps: taking the copper thioxanthone carboxylate (CU(TX)2) as the photocatalyst and the deoxidant; reducing Cu(II) in a system into Cu(I) in situ under the irradiation of sunlight; meanwhile, catalyzing ATRP (Atom Transfer Radical Polymerization) and click reaction to prepare a sequence controllable gradient copolymer. According to the method disclosed by the invention, controllable polymerization can be realized without the need of adding a ligand, so that an experiment process is greatly simplified; the sunlight is used as a light source so that energy sources are greatly saved.

The invention belongs to the technical field of preparation methods of copolymer and particularly relates to a preparation method of gradient copolymer. The preparation method of the gradient copolymer is good in capacity-increasing effect. The preparation method includes the following steps that 1, dispersion is conducted through magnetic stirring, N2 is firstly introduced into a three-opening flask equipped with a condenser pipe and an N2 injection pipe, then water, RAFT-2 and NaOH are sequentially added, stirred, dissolved and mixed to be uniform, styrene is added, rapidly stirred and pre-emulsified, and heating in a water bath is started; 2, when the water bath is heated to certain temperature, initiator is added, and F6BA monomers are added dropwise at certain speed through a trace sample injection pump; 3, after blue light happens to a system, a heat preservation reaction is conducted, and the reaction is finished, a heat source is removed, stirring continues to be conducted, after emulsion is cooled to room temperature, discharged materials are filtered through a screen, and the polymerization conversion rate is tested through a gravimetric method.