45results about How to "Increase the phenolic hydroxyl content" patented technology

The invention discloses a preparation method for preparing a lignin phenolic resin adhesive by using activated lignin to replace part of phenol to react with formaldehyde. The preparation method comprises the following steps: treating papermaking waste liquid with microwave and CuO, then filtering, adjusting the pH value to be about 2-3 by using hydrochloric acid, putting into a drying oven, standing for a period of time at a set temperature, filtering while the liquid is hot, washing to be neutral, and drying to obtain acidified lignin for later use; and taking the dried lignin to replace part of phenol, and performing phenolization, hydroxymethylation and phenolic reaction to prepare the lignin phenolic resin adhesive. By using the method disclosed by the invention, the replacement rate of phenol by lignin is improved, the cost is reduced, the pollution to the environment is reduced, the adhesive is high in bonding strength and low in free formaldehyde content, and various properties of the adhesive accord with national standards.

The invention discloses a method for increasing the content of a phenol hydroxyl of lignosulfonate by ultrasonic waves and application. The method comprises the steps that lignosulfonate is dissolved in water, the pH value of lignosulfonate is regulated to be 0-4, and stirring is performed, so that lignosulfonate is dispersed or dissolved fully, and a lignosulfonate solution is obtained; the ultrasonic waves with a service power ranging between 150W and 300W and a frequency ranging between 20kHz and 40kHz at the temperature ranging between 20 DEGC and 30 DEG C act on the lignosulfonate solution for 60-120min, and natural cooling is performed; and the cooled ultrasonic reaction solution is subjected to reduced pressure distillation and constant-temperature drying, so that lignosulfonate with increased content of the phenol hydroxyl is obtained. The method is mild in reaction condition, low in cost and environment-friendly, can be operated easily, and has a broad application prospect.

The invention relates to a straw comprehensive utilization method, and belongs to the technical field of biomass raw material comprehensive utilization. The method mainly comprises the following key steps: straw cutting treatment, dry-process dedusting, hot-water washing for sand removing, continuous cooking, spraying and receiving, multi-stage countercurrent washing, multi-stage high-concentration pulp grinding, fiber classification treatment, long-fiber concentration, long-fiber curing treatment, long-fiber pulp grinding and production of corrugated paper through long fibers, short-fiber concentration, and enzymolysis, fermentation and distillation of short fibers for production of fuel ethanol and solid granular fuel. The method has the beneficial effects that high-value comprehensive utilization of all components of the straw material is realized, chemicals are not added, a water system is closed and circulated, and the zero discharge of wastewater is realized; the specific surfacearea of a fine fiber component is large, and the enzymolysis efficiency is high; corrugated paper produced by the long fiber component is high in strength and good in quality; when the fine fiber component is used for an enzymolysis system, not only is the enzymolysis property of the material improved, but also the cost of enzymolysis sugar is greatly reduced, so that the development of a biomasscomprehensive utilization technology is promoted.

A process for preparing a series of phenolic substances includes such steps as dissolving the lignin powder recovered from waste pulp liquid in solvent, adding catalyst, high-temp and-pressure hydrogenating to obtain a series of compounds, and classifying.

The invention discloses a preparation method of a lignin-based resorcinol-phenol-formaldehyde resin adhesive. The preparation method comprises dissolving a basic catalyst in water, heating the solution to 70 to 75 DEG C, adding lignin and phenol into the solution, carrying out uniform mixing, heating the mixture to 90-95 DEG C for a phenolization reaction for 1-1.5h, cooling the mixed solution to 70-85 DEG C, supplying a basic catalyst aqueous solution, adding a formaldehyde aqueous solution into the catalyst aqueous solution, carrying out a primary polycondensation reaction process at 70-85 DEG C for 45-60min, cooling the prepared solution to 55-65 DEG C, adding a resorcinol aqueous solution into the cooled solution, carrying out a secondary polycondensation reaction at 55-65 DEG C for 60-150min and cooling the product to the room temperature. The preparation method pretreats lignin through phenolization and improves phenolic hydroxyl group content of lignin. The preparation method utilizes high activity resorcinol. The lignin-based resorcinol-phenol-formaldehyde resin adhesive has a low curing temperature and short curing time.

The invention discloses a 4-tert-alkylphenol-(phenol-based) formaldehyde resin and its preparation method and application. It is prepared from p-hydroxybenzaldehyde and 4-tert-alkylphenol through condensation and polycondensation reactions. The method of the invention has simple operation, easy implementation, mild conditions, no high pressure, high safety, strong controllability, high product yield, good quality, energy saving and environmental protection. The methyl groups of the obtained resin are connected with phenol groups, which increases the content of phenolic hydroxyl groups per unit mass of the tackifying resin. The resin is especially suitable for use as a long-term tackifying resin for rubber in the manufacture and production of tires. The initial viscosity and viscous lasting power of the sizing material added with the resin of the present invention are greatly improved, can reduce the defective rate of tires or rubber products, can improve the quality of tires or rubber products, reduce production costs and increase production efficiency, and have great advantages. Good economic and social benefits.