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

A kind of preparation method of heat-resistant cellulose nanocrystal

A technology of cellulose and nanocrystals, applied in the field of biomass materials, can solve problems such as poor dispersion, reduced surface charge, and easy agglomeration, and achieve the effects of increasing heat resistance stability, improving heat resistance, and not being easy to degrade

Active Publication Date: 2019-08-27
YANGGE MELAMINE TABLEWARE CO LTD
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when it is used as a nanofiller of a polymer matrix, especially when using conventional processing methods (extrusion, injection molding, etc.), the thermal stability of cellulose nanocrystals is poor, and it is easy to degrade and become black during melt extrusion. , In addition, in the drying process (ordinary drying, freeze drying and spray drying) of the cellulose nanocrystal suspension, there will usually be different degrees of agglomeration
[0003] At present, the improvement of the thermal stability of cellulose nanocrystals mainly focuses on the following two aspects: (1) surface modification of cellulose nanocrystals, such as replacing the hydroxyl groups on the surface of cellulose nanocrystals with acetyl groups or other heat-resistant groups, But the improvement effect is limited
(2) Improve the extraction process and reduce the introduction of sulfonic acid groups, such as hydrolyzing fiber raw materials with hydrochloric acid and phosphoric acid instead of sulfuric acid. Although the thermal stability of nanocellulose prepared by this method is improved, the surface charge is reduced and agglomeration is prone to occur , poor dispersion

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
  • A kind of preparation method of heat-resistant cellulose nanocrystal
  • A kind of preparation method of heat-resistant cellulose nanocrystal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] The cellulose nanocrystal (ie untreated cellulose nanocrystal uCNC) suspension obtained by hydrolyzing bamboo powder with sulfuric acid was centrifuged, and the supernatant was discarded. The centrifugation conditions adopted were 9000 rpm and 6 min. Then use a NaOH aqueous solution with a concentration of 0.1mol / L to wash and then centrifuge again to remove the supernatant; repeat the NaOH solution with this concentration to wash and centrifuge until the pH value of the cellulose nanocrystal suspension is about 10 and then let it stand for about 6h; then After centrifugation, the supernatant was discarded, and then washed with deionized water to obtain alkali-treated cellulose nanocrystals (expressed as aCNC).

[0029] Add deionized water to the treated cellulose nanocrystal suspension to adjust the mass concentration to 1%, take 1000g of cellulose nanocrystal suspension; first use ultrasonic power of 200W to ultrasonically disperse the cellulose nanocrystal suspension ...

Embodiment 2

[0033] The cellulose nanocrystal suspension obtained by hydrolyzing wood powder with sulfuric acid was centrifuged, and the supernatant was discarded. The centrifugation conditions adopted were 10000 rpm and 7 min. Then use the KOH aqueous solution with a concentration of 0.15mol / L to wash and then centrifuge again to remove the supernatant; repeat the KOH solution with this concentration to wash and centrifuge until the pH value of the cellulose nanocrystal suspension is about 11, and let it stand for about 8h; centrifuge The supernatant was discarded, and then washed with deionized water for later use.

[0034] Add water to the treated cellulose nanocrystal suspension to adjust the mass concentration to 0.8%, take 1000g of cellulose nanocrystal suspension; first use the ultrasonic power of 250W to ultrasonically disperse the suspension for about 25min, and then place it in a water bath at 50°C Heat in medium and slowly add 10 g of polyethylene oxide (PEO, molecular weight: 5...

Embodiment 3

[0036] The cellulose nanocrystal suspension obtained by hydrolyzing rice bran with hydrochloric acid was centrifuged, and the supernatant was discarded. The centrifugation conditions adopted were 9000 rpm and 5 minutes of centrifugation time. Then use 0.2mol / L KOH aqueous solution to wash and then centrifuge again to remove the supernatant; repeat the use of this concentration of KOH solution to wash and centrifuge until the pH value of the cellulose nanocrystal suspension is about 10, then let it stand for about 10h; after centrifugation Discard the supernatant and wash with deionized water for later use.

[0037] Add water to the treated cellulose nanocrystal suspension to adjust the mass concentration to 0.5%, and take 1000g of cellulose nanocrystal suspension; first use ultrasonic power of 200W to ultrasonically disperse the suspension for about 30min, and then place it in a water bath at 50°C Heat in the pot and slowly add 10 g of polyethylene oxide (PEO-50W), and use mec...

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

No PUM Login to View More

Abstract

The invention discloses a preparing method for a heat-resisting cellulose nanocrystal. According to the method, supernatant of cellulose nanocrystal suspension liquid obtained after acid hydrolysis of plant fibers is removed through centrifugal separation, then an alkaline solution of 0.05-0.2 mol / L is used for conducting repeated washing and centrifuging multiple times till the pH of the obtained cellulose nanocrystal suspension liquid ranges from 8 to 11, centrifugal separation is conducted after standing is conducted for 5 h to 30 h, and then deionized water is used for washing the cellulose nanocrystal suspension liquid to be neutral; then the mass concentration of the obtained cellulose nanocrystal suspension liquid is adjusted to be 0.5%-1%, and ultrasonic dispersion is conducted; stirring is conducted in a water bath kettle, a water-soluble polymer is added and is evenly scattered in the cellulose nanocrystal suspension liquid; and drying is conducted, and the heat-resisting cellulose nanocrystal is obtained. According to the preparing method, the heat stability performance of the cellulose nanocrystal can be improved, in addition, the dispersion effect of the cellulose nanocrystal is improved, and agglomeration of the cellulose nanocrystal in a polymer matrix is reduced.

Description

technical field [0001] The invention relates to cellulose, in particular to a method for preparing heat-resistant cellulose nanocrystals, and belongs to the field of biomass materials. Background technique [0002] Cellulose is one of the most abundant natural polymers in nature, and its advantages lie in its degradability and recyclability. Cellulose nanocrystals extracted from cellulose show great application prospects in high-performance composite materials due to their light weight, high purity, high crystallinity, high Young's modulus, and high strength. However, when it is used as a nanofiller of a polymer matrix, especially when using conventional processing methods (extrusion, injection molding, etc.), the thermal stability of cellulose nanocrystals is poor, and it is easy to degrade and become black during melt extrusion. , In addition, during the drying process (ordinary drying, freeze drying and spray drying) of the cellulose nanocrystal suspension, different deg...

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 Patents(China)
IPC IPC(8): C08L71/02C08L1/04C08L29/04C08B15/02
Inventor 何慧陈剑孟淑娜黄柏
Owner YANGGE MELAMINE TABLEWARE CO LTD