Preparation method of high-lignin content phenolic foam

A technology of phenolic foam and lignin, which is applied in the field of preparation of lignin-based phenolic foam, can solve the problems of high resin viscosity and affecting foaming, and achieve the effect of reducing resin density, reducing viscosity and ensuring uniformity

Active Publication Date: 2018-07-06
TIANJIN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In view of the high viscosity of the resin during the phenolic foaming process with high lignin content, which affects the subsequent foaming, the low boiling point lignin excellent solvent is used to reduce the viscosity, and then the compressive strength of the resin is ensured by curing with inorganic strong acid

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Get 63 mass parts of lignin in a three-necked flask, add 94 mass parts of melted phenol (40% lignin replacement rate) and 72 mass fractions of 20% aqueous sodium hydroxide solution at a temperature of 45°C, and start the stirrer Stir for 10 minutes, add 72 parts by mass of formaldehyde solution with a mass fraction of 37%, react at 65°C for 60 minutes, raise the temperature to 90°C for another 60 minutes, and cool down to 30°C after the reaction is complete. , use 4mol / L hydrochloric acid to neutralize the pH of the resin to 7, let stand, and separate layers. The water in the upper layer is removed to obtain a lignin-containing expandable resin. Take 100 parts by mass of expandable resin, add 2 parts by mass of methanol solution, stir and mix evenly, add 6 parts by mass of Tween 80 and 12 parts by mass of n-pentane, stir quickly and add 10 parts by mass of concentrated hydrochloric acid, continue to stir evenly , poured into an open paper mold, placed in an oven at 75°...

Embodiment 2

[0014] Take 94 parts by mass of lignin in a three-necked flask, add 94 parts by mass of melted phenol (substitution rate of 50%) and 87 parts by mass of 20% aqueous sodium hydroxide solution at a temperature of 50°C, and start the stirrer to stir for 10 minutes , add 82 parts by mass of formaldehyde solution with a mass fraction of 37%, react at 60°C for 60 minutes, raise the temperature to 92°C for another 50 minutes, cool down to 35°C after the reaction, and stir with 4mol / L hydrochloric acid neutralized the pH of the resin to 7.5, allowed to stand, and separated into layers. The water in the upper layer is removed to obtain a separable resin containing lignin. Take 100 parts by mass of expandable resin, add 4 parts by mass of methanol solution, stir and mix evenly, add 6 parts by mass of Tween 80 and 15 parts by mass of n-pentane, stir quickly and mix uniformly, add 15 parts by mass of concentrated hydrochloric acid, and continue stirring Evenly, pour into an open paper mo...

Embodiment 3

[0016] Take 141 parts by mass of lignin in a three-necked flask, add 94 parts by mass of melted phenol (60% substitution rate) and 110.5 parts by mass of 20% aqueous sodium hydroxide solution at a temperature of 55°C, and start the stirrer to stir for 15 minutes , add 98 parts by mass of formaldehyde solution with a mass fraction of 37%, react at 65°C for 45 minutes, raise the temperature to 90°C for another 45 minutes, cool down to 35°C after the reaction, and stir with 4mol / L of hydrochloric acid neutralizes the pH of the resin to 8, leaves standstill, and separates layers. The water in the upper layer is removed to obtain a lignin-containing expandable resin. Take 100 parts by mass of expandable resin, add 6 parts by mass of methanol solution, stir well, add 8 parts by mass of Tween 80 and 15 parts by mass of n-pentane, stir quickly and mix well, then add 18 parts by mass of concentrated hydrochloric acid, and continue stirring Evenly, pour into an open paper mold, place i...

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Abstract

The invention relates to a preparation method of high-lignin content phenolic foam and belongs to the field of preparation of insulating foam materials. The preparation method comprises the followingsteps: mixing lignin and a certain quantity of phenol and formaldehyde according to the substitution rate, synthesizing expandable lignin-based phenolic resin under alkaline conditions, adding a low-boiling point lignin excellent solvent to reduce the resin viscosity, then mixing with a surfactant and a foaming agent and finally curing with inorganic strong acid to prepare the high-lignin contentphenolic foam. The preparation method provided by the invention has the advantages that aiming at the problem of high viscosity of the resin in the high-lignin phenolic foaming process, after the viscosity of a system is reduced by utilizing the lignin excellent solvent, the compression strength of the resin is guaranteed by curing with the inorganic strong acid; the substitution rate of the lignin in the lignin-based phenolic foam is improved, the dependence of the phenolic resin on petrochemical raw materials is reduced, and the preparation cost of the phenolic foam is reduced; economic andenvironmental benefits are important.

Description

technical field [0001] The invention relates to a method for preparing lignin-based phenolic foam, in particular to a method for preparing phenolic foam with high lignin content. Background technique [0002] With the deepening of people's understanding of environmental pollution and resource crisis, the renewable and degradable properties of natural polymers have attracted increasing attention from scientists. Lignin is the second largest renewable biomass resource after cellulose, and its yield in nature is second only to cellulose. It is called an "insoluble plant polymer" with an aromatic structure and a highly cross-linked structure. At present, industries that use plant fibers as raw materials, such as paper industry, cellulose materials, textile industry and other biomass industries, basically discharge lignin as waste, which not only wastes resources, but also seriously pollutes the environment. It is of great significance to recycle lignin to replace non-renewable ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J9/14C08L61/14C08G8/28
CPCC08G8/28C08J9/141C08J2203/14C08J2361/14
Inventor 王冠华司传领张佳音
Owner TIANJIN UNIV OF SCI & TECH
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