摘要:
The present invention provides a fully vulcanized thermoplastic elastomer comprising a rubber phase with a controllable particle size and a spheroidic shape, the preparation and use thereof. Fully vulcanized powdery rubber is blended with plastic by conventional method for blending rubbers, and thus obtaining a fully vulcanized thermoplastic elastomer, which comprises a rubber phase with a controllable particle size and a spheroidic shape, and which shows high tensile strength and high elongation at break, good appearance and good processibility.
摘要:
The present invention provides plastics with high toughness and the preparation thereof. The plastics with high toughness, which have the balance of stiffness and toughness, stable properties and good processability, are obtained by blending the rubber particles having an average particle size of 20 to 200 nm with the pseudoductile plastics, wherein the weight ratio of the rubber particles to the plastics is from 0.5:99.5 to 70:30. The present invention also provides plastics with both high stiffness and high toughness and the preparation thereof. The plastics with both high stiffness and high toughness, which have also an improved heat resistance and good processability, are prepared by blending the rubber particles having an average particle size of 20 to 500 nm and the crystalline plastics, wherein the amount of the rubber particles added in the plastics matrix is from 0.3 to 5 weight parts.
摘要:
The present invention relates to a novel fully vulcanized powdery silicone rubber, preparation and use thereof. The fully vulcanized powdery silicone rubber is prepared from an latex of organosilicon polymer or copolymer with lower molecular weight via irradiation of high-energy rays. The gel content of the obtained fully vulcanized powdery silicone rubber is at least 60% by weight. The fully vulcanized powdery silicone rubber can be combined with various plastics and is very easy to be dispersed into plastic matrix, and can be used as toughening agent, processing aids or as additives for cosmetics, ink, paint and coatings.
摘要:
The present invention provides a fully vulcanized powdery rubber having a particle size of from 20 to 2000 nm, its preparation and use. The vulcanized powdery rubber is obtained by irradiating a rubber latex having a particle size of from 20 to 2000 nm with a high-energy irradiation. The vulcanized powdery rubber is very easily to be dispersed into various plastics, and thus can be mixed with various plastics to prepare toughened plastics and fully valcanized thermoplastic elastomers.
摘要:
A toughened plastic and its preparation method, with the toughened plastic being obtained by rubber-plastic blending of brittle or less brittle plastics and a rubber mixture. The rubber mixture consists of powdery rubbers having a cross-linked structure and an average particle size of not more than 0.50 μm, and at least one selected from the group consisting of unvulcanized rubbers and thermoplastic elastomers. The morphology and the particle size distribution of the rubber phase contained in the toughened plastic can be controlled by changing the particle size of the powdery rubbers having a cross-linking structure and choosing proper unvulcanized rubbers or thermoplastic elastomers. The toughened plastic has good toughness and processability while keeping better strength and stiffness.
摘要:
The present invention provides a propylene polymer composition for producing a biaxially oriented film, comprising propylene random copolymer and propylene homopolymer; wherein the propylene random copolymer is a copolymer of propylene and ethylene, optionally comprising one or more alpha-olefins of C4-C10; the propylene polymer composition has an overall isotacticity index, as determined by nuclear magnetic resonance method, of greater than or equal to 96.5%, and an ethylene content of greater than 0.3 wt %; and wherein, the melt flow rate of the propylene random copolymer is lower than that of the propylene homopolymer. The biaxially oriented polypropylene film produced by the propylene polymer composition of the present invention exhibits excellent physical properties, and has, in the absence of any stiffening agent, relatively higher modulus and stiffness. Moreover, the process for producing the biaxially oriented polypropylene film is featured with a good film-forming stability and a high film-forming stretching speed.
摘要:
The present invention provides a propylene polymer composition for producing a biaxially oriented film, comprising propylene random copolymer and propylene homopolymer; wherein the propylene random copolymer is a copolymer of propylene and ethylene, optionally comprising one or more alpha-olefins of C4-C10; the propylene polymer composition has an overall isotacticity index, as determined by nuclear magnetic resonance method, of greater than or equal to 96.5%, and an ethylene content of greater than 0.3 wt %; and wherein, the melt flow rate of the propylene random copolymer is lower than that of the propylene homopolymer. The biaxially oriented polypropylene film produced by the propylene polymer composition of the present invention exhibits excellent physical properties, and has, in the absence of any stiffening agent, relatively higher modulus and stiffness. Moreover, the process for producing the biaxially oriented polypropylene film is featured with a good film-forming stability and a high film-forming stretching speed.
摘要:
The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-unifomess of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.
摘要:
This invention provides a method for preparing cycloastragenol monoglucoside CMG (cycloastragenol-6-O-β-D-glucoside), comprising the steps of: a. using astragaloside IV or Astragali extracts prepared by a conventional method as raw materials and adding an appropriate solvent thereinto to form a raw material solution; b. adding hydrolase and allowing for hydrolysis at a constant temperature to obtain a hydrolysate; c. separating the hydrolysate with macroporous adsorption resin; and d. obtaining the product by purification and separation. The present invention further provides cycloastragenol-6-O-β-D-glucoside prepared according to the method of this invention as well as its use in the preparation of a medicament for treating cardiovascular diseases and pharmaceutical compositions comprising the same.
摘要:
The present invention relates to the field of a medicine for treating diseases associated with inflammation, immunity or infection, and in particular, to glycyrrhetinic acid-30-amide derivatives of general formula I and their preparation, and a pharmaceutical composition containing the same. Said derivatives and composition exhibit anti-inflammatory, analgesic, anti-allergic, cough-preventing, liver-protecting and anti-viral properties, wherein each group is as defined in the description.