41results about How to "High dynamic viscosity" patented technology

The invention discloses novel high viscosity asphalt and a preparation method thereof. The novel high viscosity asphalt comprises the following raw materials in parts by weight: 100 parts of base asphalt with high asphaltene content, 0.1-1.2 part of polyphosphoric acid, 2-12 parts of a ductility improver mother liquid, 1-8 parts of a dispersant, and 0.2-0.5 part of a coupling agent. The preparation method comprises the following steps: adding the polyphosphoric acid in the molten base asphalt to perform a chemical modification reaction, then adding the ductility improver mother liquid, continuing to react, and finally adding the dispersant and the coupling agent to continue to react for a period of time to prepare high viscosity asphalt, wherein the whole process is performed under a highs-speed stirring condition. The high viscosity asphalt is high in 60-degree dynamic viscosity, high in softening point, high in low-temperature ductility, stable to store, and good in adhesion to aggregates, has excellent high temperature stability, excellent low temperature anti-cracking performance, excellent anti-fatigue performance and excellent water resistance, is especially suitable for high-temperature humid areas, areas with relatively high diurnal temperature difference, and paving of heavy-duty roads and drainable pavements, effectively prevents common pavement damages such as pavement rutting, pavement upheaval, pavement fatigue cracking, pavement cold cracking and water encroachment on pavements, and prolongs the service life of the pavement.

Disclosed are a sunscreen composition comprising surface-defected cerium oxide particles and a method for preparing the sunscreen composition. The sunscreen composition comprising surface-defected cerium oxide particles has excellent bacterial-species killing ability, can have a high sun protection factor (SPF) and PA level, and can exhibit excellent dispersion stability since layer separation does not occur even if a long time passes.

The present invention provides a method for the preparation of a class of injectable gels having cohesion-enhancing properties after autoclaving. The chemically cross-linked amide bond in the system makes the gel have a strong ability to resist short-term high-temperature and high-pressure damage, and the free carboxyl and amino groups will form ionic bonds through electrostatic attraction due to the slow movement of the molecular chain, making the system sterilized. After a period of time, the dynamic viscosity continued to increase, and finally reached a plateau and exceeded the dynamic viscosity before sterilization. The enhanced cohesion endows the gel with good stability, which can maintain its shape for a long time without dispersion in a liquid environment. A suitable degree of crosslinking confers injectability to the gel. The enhanced cohesion and injectability make the gel system have strong application prospects in the field of biomedicine, especially in the direction of implantation in vivo, such as drug loading, filling, tissue repair, etc.

The invention relates to method for improving 60 DEG C dynamic viscosity of pavement petroleum asphalt, which comprises the steps that atmospheric or vacuum residual oil serves as a raw material, is heated by a heating furnace, enters an asphalt tackifying reactor to be subjected to tackifying reaction, and then enters an atmospheric flash tower for separating out light gas oil; and oil at the bottom of the tower enters a vacuum heating furnace for heating, then enters a vacuum tower to be decompressed and fractionated. The vacuum residual oil at the bottom of the tower is the pavement petroleum asphalt product of which the viscosity is improved. Compared with the asphalt prepared by the same raw material and with a distillation method, the 60 DEG C dynamic viscosity of the pavement petroleum asphalt product prepared by the method with the same mark (the same needle penetration) is improved, so that the high-temperature property of the asphalt is improved.

The invention discloses technology for producing direct spinning terylene industrial filaments after liquid state polycondensation of prepolymer and belongs to the technical field of spinning. The technology comprises the processes of esterification, prepolycondensation, liquid state polycondensation, and spinning, and is characterized by comprising the following steps of: performing prepolycondensation reaction on esterified ethylene glycol and phthalic acid to prepare a melt with the viscosity of 0.3 to 0.4dl / g, and conveying the melt to a liquid state polycondensation kettle for liquid state polycondensation by using a booster pump; and conveying the melt to a spinning beam for spinning through a gear pump, wherein the inherent viscosity of the polyester melt after liquid state polycondensation is 0.85 to 1.05dl / g. By directly conveying the melt into the liquid state polycondensation kettle for polycondensation and performing the production technology of directly spinning the melt,the production technology for producing the direct spinning terylene industrial filaments after the liquid state polycondensation of the prepolymer shortens the process flow, reduces the production energy consumption and production cost, and solves the technical problem of difficulty in conveying the melt simultaneously.

The invention relates to hyaluronic acid composite cross-linked hydrogel and a preparation method thereof. By combining the characteristic that an active group of hyaluronic acid can be used as a chemical modification site with the characteristic of polyanion electrolyte of hyaluronic acid, different groups and different spatial conformations of the substances such as 1,4-butanediol diglycidyl ether, polyethylene glycol, sodium alginate and gelatin are utilized to perform composite crosslinking and modifying with hyaluronic acid, and the proportion of each component is analyzed to determine the optimum formula of each component in the crosslinking reaction; the molecular weight of the prepared hyaluronic acid composite hydrogel is obviously increased, especially, the dynamic viscosity of the prepared hyaluronic acid composite hydrogel is remarkably increased. The hyaluronic acid composite cross-linked hydrogel prepared by the preparation method disclosed by the invention is great in molecular weight and great in dynamic viscosity, has the advantages of relatively strong space blocking effect and lubricating effect, good biocompatibility, good stability, and the like, and can be used for a tissue filling material, a lubricant in an articular cavity and a tissue adhesion preventing material of operation.