Unlock instant, AI-driven research and patent intelligence for your innovation.

Preparation method of modified lignin polyol and polyurethane hot melt adhesive thereof

A polyurethane hot-melt adhesive and lignin technology, applied in the field of polyurethane, can solve the problems of excessive release of formaldehyde from adhesives, limit the wide application of lignin, and low reactivity, and achieve high bonding strength, improved solubility, and improved reaction. active effect

Active Publication Date: 2022-04-29
SOUTH CHINA AGRI UNIV
View PDF14 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, the above modification methods also have many disadvantages, such as low reactivity between the phenolic hydroxyl group generated by demethylation and isocyanate, methylolation leads to excessive release of formaldehyde from the adhesive, and liquefaction requires high temperature and high pressure treatment, resulting in high energy consumption and high cost. Wide application of lignin in polyurethane materials

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of modified lignin polyol and polyurethane hot melt adhesive thereof
  • Preparation method of modified lignin polyol and polyurethane hot melt adhesive thereof
  • Preparation method of modified lignin polyol and polyurethane hot melt adhesive thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] Weigh 10g of enzymatic lignin and dissolve it in DMF, add 13g of chlorohexanol, 22g of potassium carbonate, 2.5g of sodium iodide and 2.5g of tetrabutylammonium bromide, and react at 85°C for 48 hours. After the reaction, wait for the reaction solution to cool to room temperature, add the reaction solution to a beaker filled with a large amount of deionized water, adjust the pH to 2-3 with dilute hydrochloric acid aqueous solution, let it stand overnight, and filter off the supernatant; In DMF, add a large amount of deionized water, repeat the above steps for secondary re-precipitation, collect and dry the solid to obtain modified lignin and seal it for future use (the grafting rate of hydroxyhalohydrocarbons was detected to be 75%).

Embodiment 2

[0052] Same as Example 1, the difference is that the reaction time of 48h is replaced by 24h. The modified lignin is obtained and sealed for future use (the grafting rate of hydroxyhalogenated hydrocarbons is detected to be 50%).

Embodiment 3-4

[0054] Same as Example 1, the difference is that the enzymatic lignin is replaced by alkali lignin and sulfate lignin.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
shear strengthaaaaaaaaaa
shear strengthaaaaaaaaaa
degree of graftingaaaaaaaaaa
Login to View More

Abstract

The invention relates to the technical field of polyurethane, in particular to a preparation method of modified lignin polyol and a polyurethane hot melt adhesive thereof. The modified lignin polyol is obtained by modifying phenolic hydroxyl groups and carboxyl groups on lignin into alcoholic hydroxyl groups by taking hydroxyl halogenated hydrocarbon as a modifier. The reaction activity of phenolic hydroxyl groups and carboxyl groups in original lignin with polyurethane is low, and the phenolic hydroxyl groups and carboxyl groups on the lignin are modified into alcoholic hydroxyl groups with high reaction activity with isocyanate through a hydroxyl halogenated hydrocarbon nucleophilic substitution reaction, so that the solubility and reaction activity of the lignin are improved. The modified lignin polyol, isocyanate and other auxiliary reagents are utilized to prepare the polyurethane hot melt adhesive with uniform texture and high bonding strength.

Description

technical field [0001] The invention relates to the technical field of polyurethane, in particular to a preparation method of modified lignin polyol and polyurethane hot melt adhesive. Background technique [0002] Polyurethane hot melt adhesive is a solvent-free one-component green adhesive, which has the advantages of water resistance, low temperature resistance, no VOC release, simple sizing process, and easy continuous production. Polyurethane hot melt adhesives are mainly divided into two types: thermoplastic type and reactive type. The current thermoplastic polyurethane hot melt adhesive is fast curing and can be reused, but its bonding strength, solvent resistance and heat resistance are poor; while the reactive polyurethane hot melt adhesive has high bonding strength, but has low initial bonding strength and slow curing speed. Wait for the disadvantages. Therefore, it is difficult for conventional polyurethane hot melt adhesives to meet the requirements of fast bon...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C08H7/00C08G18/64C08G18/28C09J175/04
CPCC08H6/00C08G18/6492C08G18/286C09J175/04
Inventor 刘珍珍刘涛郑碧霞欧荣贤王清文郭垂根都蕾
Owner SOUTH CHINA AGRI UNIV