CN108589365B - The method that polishing prepares II crystal type nano fiber of lignocellulosic - Google Patents
The method that polishing prepares II crystal type nano fiber of lignocellulosic Download PDFInfo
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
- D21B1/00—Fibrous raw materials or their mechanical treatment
- D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
- D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
- D21B1/30—Defibrating by other means
- D21B1/34—Kneading or mixing; Pulpers
- D21B1/345—Pulpers
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Abstract
The present invention relates to the methods that polishing of one kind prepares II crystal type nano fiber of lignocellulosic, comprising the following steps: (1) removes partial lignin；(2) strong base solution is handled；(3) residual lignin is removed；(4) a mechanical polishing.Advantage: 1) using a polishing, simple process, and energy consumption reduces, and yield improves, and operation difficulty is reduced with cost is produced；2) gained nanofiber is cellulose Ⅱ crystal type nano fiber, and diameter is evenly distributed, and thermodynamic property is stablized；3) wood powder mixed solution is handled with sodium chlorite and glacial acetic acid, remove the partial lignin in wood powder, remaining lignin can effectively inhibit the phenomenon that highly basic handles caused cellulose and reunites on a large scale in wood powder, subsequent mechanical treatment is carried out again, gained cellulose Ⅱ crystal type nano fiber yield is increased dramatically after primary grinding, up to 80-85%.
Description
Technical field
The present invention is a kind of method that polishing prepares II crystal type nano fiber of lignocellulosic, belongs to nano-cellulose skill
Art field.
Background technique
Cellulose is the most abundant natural polymer on the earth, is existed in nature with the formation of nano-cellulose.It
It is photosynthetic Primary product under terrestrial environment, and potential as a kind of recyclable organism of the energy and chemical field money
Source.Nano-cellulose has the advantages that high Young's modulus, high intensity, high-specific surface area, renewable, biodegradable, by
Nano-cellulose is filled in various polymeric matrixs and produces cellulose based nano composite material, for materials such as reinforced plastics to mention
Its high added value and functionality, are increasingly becoming research hotspot instead of conventional composite materials, have biggish application prospect.
Cellulose is a kind of polycrystalline material, and so far, research finds cellulose, and there are five kinds of crystal modifications, i.e., naturally
Cellulose (cellulose Ⅰ), artificial cellulose II, III, IV and cellulose Ⅹ, this five kinds of crystal modifications have different structure cell knots
Structure, and can be mutually converted between crystal modification under certain condition.Wherein conversion of the cellulose Ⅰ to cellulose Ⅱ is not
Reversible, therefore cellulose Ⅱ is the most stable of form of thermodynamics in these types of crystal modification, from the point of view of technology and business perspective
This is also very important cellulose crystallite form.About the research of nano-cellulose, Today, most research is focused primarily upon
Cellulose I crystal form, and the nano-cellulose preparation method of cellulose Ⅱ crystal form is less and existing method is complex.
Cellulose Ⅱ can be obtained by regeneration in solution or mercerization by cellulose Ⅰ at present.Dissolve regeneration method
Mainly native cellulose is dissolved in appropriate solvent, the cellulose being precipitated out then is extracted from solution；Mercerising process is
Native cellulose is allowed to generate alkali cellulose in high alkali liquid (such as 17.5 % NaOH) swollen, then dry by distillation water washing
It is recrystallized to cellulose Ⅱ.Although cellulose Ⅱ nanoparticle can be prepared by dissolution regeneration and TEMPO method for oxidation, its
Draw ratio and crystallinity all have substantial degradation, and also it is difficult to extract the cellulose to high-purity from wood powder, cellulose is obtained
Rate is also mostly lower.
Summary of the invention
Proposed by the present invention is a kind of method that polishing prepares II crystal type nano fiber of lignocellulosic, its purpose is that
Solution produce in the prior art cellulose Ⅱ crystal type nano fiber there are the step of it is many and diverse and energy consumption is high, gained nano-cellulose is straight
The problems such as diameter is unevenly distributed, efficiency of pcr product is lower, a polishing for providing a kind of simplicity prepare cellulose Ⅱ crystal type nano fibre
The method of dimension.
Technical solution of the invention: the method that a polishing prepares II crystal type nano fiber of lignocellulosic, packet
Include following steps:
(1) partial lignin is removed；
(2) strong base solution is handled；
(3) residual lignin is removed；
(4) a mechanical polishing.
Beneficial effects of the present invention:
1) polishing, simple process are used, energy consumption reduces, and yield improves, and operation difficulty is reduced with cost is produced；
2) gained nanofiber is cellulose Ⅱ crystal type nano fiber, and diameter distribution is uniform, is 15-50 nm, thermodynamics
It can stablize；
3) wood powder mixed solution is handled with sodium chlorite and glacial acetic acid, removes the partial lignin in wood powder, can effectively presses down
The phenomenon that cellulose caused by highly basic processed is handled is reunited on a large scale, then subsequent mechanical treatment is carried out, it is fine obtained by a polishing
It ties up plain II crystal type nano fiber yield to be increased dramatically, up to 80-85%.
Specific embodiment
The method that polishing prepares II crystal type nano fiber of lignocellulosic, comprising the following steps:
(1) partial lignin is removed；
(2) strong base solution is handled；
(3) residual lignin is removed；
(4) a mechanical polishing.
Step (1) the removal partial lignin comprises the following steps that:
1) 1:15 in mass ratio ~ 30 weighs wood powder and distilled water, is uniformly mixed；The wood powder is the wood powder of 50-300 mesh.
2) sodium chlorite and glacial acetic acid is added to acquired solution, it is dense for 1-2 wt %, glacial acetic acid is made into sodium chlorite concentrations
Degree is the solution of 2-5 vol%, and adjusting makes pH value of solution 4-5, is put into 2 ~ 3h of heating in 73-78 DEG C of water-bath；Period every 1 ~
1.5h adds sodium chlorite and glacial acetic acid into solution, so that the concentration of sodium chlorite is maintained at 1-2 wt %, solution in solution
PH value is maintained at 4-5；
3) distilled water of the mixed solution after sodium chlorite and glacial acetic acid are processed is filtered into cleaning to neutrality, vacuum
It filters to not dripping, obtains the filter pulp under water swollen state；
It is first handled with sodium chlorite and glacial acetic acid, removes the partial lignin in wood powder, in the feelings for retaining partial lignin
Carrying out processing using aqueous slkali under condition can inhibit the phenomenon that NaOH processing makes that extensive reunion occurs between cellulose well,
This agglomeration will lead to subsequent mechanical nanosizing difficulty and greatly increase.
Step (2) the strong base solution processing comprises the following steps that:
1) filter pulp that step (1) processing obtains is added in NaOH aqueous slkali and is diluted, NaOH is dense in the solution after dilution
Degree is 15-19 wt%, stands >=10 h at room temperature after sealing stirring；2) acquired solution distilled water is filtered into cleaning into
Property, it is filtered by vacuum to not dripping, obtains filter pulp；
Being handled with strong base solution by cellulose I transformation of crystal is crystal form of cellulose II, and removes the major part in wood-fibred
Hemicellulose.
Step (3) the removal residual lignin comprises the following steps that:
1) 1:15 in mass ratio ~ 30 weighs the filter pulp and distilled water that step (2) processing obtains, and stirs evenly, is put into 75 DEG C
Heat 3-4.5h in water-bath, during which add sodium chlorite and glacial acetic acid into solution every 1 ~ 1.5h, so that in solution
The concentration of sodium chlorite is maintained at 1 wt %-2 wt %, and solution ph is maintained at 4-5, until sample turned white；
2) by acquired solution wash with distilled water to filtering after neutral, it is 0.5 ~ 1 that resulting filter pulp, which is configured to mass concentration,
The aqueous suspension of wt%.
Reuse the lignin of sodium chlorite and glacial acetic acid removing remnants.
The mechanical polishing of the step (4): 1) aqueous suspension for obtaining step (3) processing is in stone mortar extra-fine grinding
It is ground in instrument once, scale is -0.6mm to -0.8mm, and revolving speed is 1200-1600 r/min, time 10-60min.
In chemical acid alkali treatment process, cellulose agglomeration caused by effectively highly basic being inhibited to handle, then carry out subsequent
Mechanical treatment, gained cellulose Ⅱ crystal type nano fiber yield significantly improves.
The wood powder is the wood powder of 50-300 mesh.
Bamboo powder can also prepare diameter using method of the same race and be distributed cellulose Ⅱ crystal form uniform, that thermodynamic property is stable
Nanofiber.
Embodiment 1
Handled using chemical treatment method: (1), weigh 60 mesh pine powder 50g and 950ml distilled water be uniformly mixed, be put into
Heat 2h in 75 DEG C of water-baths；(2), sodium chlorite 10g is added to step (1) acquired solution to be made into sodium chlorite quality dense
Degree is the solution of 1 wt%, and it is 4-5 that 2 ~ 5ml glacial acetic acid, which is added, to adjust its pH, and 10g is during which added into mixed solution every 1h
Sodium chlorite and 2 ~ 5ml glacial acetic acid solution, maintenance sodium chlorite mass concentration are 1 wt%, pH value 4-5；(3), to step (2)
Solution up to neutrality and carries out filtering acquisition filter pulp wash with distilled water after mixed solution cooling after processing；(4), by upper one
The filter pulp that step is handled, which is added in NaOH aqueous slkali, to be diluted, and NaOH concentration is 17.5 wt%, sealing in the solution after dilution
12 h are stood after stirring at room temperature；(5), the solution by step (4) after processed to neutrality and is taken out wash with distilled water
Filter；(6), the aqueous solution that appropriate distilled water is configured to 1000ml is added in the filter pulp obtained to step (5), is put into 75 DEG C of water-baths
Middle heat treatment 3.5h, and repeat the treatment process of step (2).
It is handled using the method for mechanical treatment: (1) filtering, weigh after cleaning the solution after chemical treatment to neutrality
The filtered filter pulp of 36g is added 964ml and is configured to the aqueous suspension that mass concentration is 0.8 wt%, by stone mortar extra-fine grinding instrument
Scale be adjusted to -6, in the case where revolving speed is 1400 r/min, 10 ~ 40min of grinding is to uniform.
Embodiment 2
Handled using chemical treatment method: (1), weigh 60 mesh wood powder 25g and 475ml distilled water be uniformly mixed, be put into 76
Heat 3h in DEG C water-bath；(2), sodium chlorite 10g is added to step (1) acquired solution and is made into sodium chlorite mass concentration
For the solution of 2wt%, and it is 4-5 that 1 ~ 2ml glacial acetic acid, which is added, to adjust its pH, and it is sub- that 20g is during which added into mixed solution every 1.5h
Sodium chlorate and 1 ~ 2ml glacial acetic acid solution, maintenance sodium chlorite mass concentration are 2wt%, pH value 4-5；(3), to step (2)
Solution up to neutrality and carries out filtering acquisition filter pulp wash with distilled water after mixed solution cooling after reason；(4), by previous step
It handles obtained filter pulp and is added in NaOH aqueous slkali and dilute, NaOH concentration is 17.5 wt% in the solution after dilution, and sealing is stirred
10 h are stood after mixing at room temperature；(5), the solution by step (4) after processed to neutrality and filters wash with distilled water；
(6), the aqueous solution that appropriate distilled water is configured to 500ml is added in the filter pulp obtained to step (5), is put into 75 DEG C of water-baths and adds
It is heat-treated 3h, and repeats the treatment process of step (2).
It is handled using the method for mechanical treatment: (1) filtering, weigh after cleaning the solution after chemical treatment to neutrality
The filtered filter pulp of 36g is added 964ml and is configured to the aqueous suspension that mass concentration is 0.8 wt%, by stone mortar extra-fine grinding instrument
Scale be adjusted to -7, revolving speed be 1300 r/min under grind 10 ~ 50min.
Embodiment 3
Handled using chemical treatment method: (1), weigh 80 mesh wood powder 50g and 950ml distilled water be uniformly mixed, be put into 75
Heat 2 h in DEG C water-bath；(2), it is 1 that sodium chlorite 10g is added into acquired solution and is made into sodium chlorite mass concentration
The solution of wt%, and it is 4-5 that 2 ~ 5ml glacial acetic acid, which is added, to adjust its pH, and 10g chlorous acid is during which added into mixed solution every 1h
Sodium and 2 ~ 5ml glacial acetic acid solution, maintenance sodium chlorite mass concentration are 1 wt%, pH value 4-5；(3), solution to be mixed is cooling
Solution up to neutrality and carries out filtering acquisition filter pulp wash with distilled water afterwards；(4), filter pulp obtained in the previous step is added to
It is diluted in NaOH aqueous slkali, NaOH concentration is 18 wt% in the solution after dilution, stands 12h at room temperature after sealing stirring；
(5), the solution after processing to neutrality and filters wash with distilled water；(6), appropriate steam is added into the filter pulp of acquisition
Distilled water is configured to the aqueous solution of 1000ml, is put into 75 DEG C of water-baths and heats 3h, and repeats the treatment process of step (2).
It is handled using the method for mechanical treatment: (1) filtering, weigh after cleaning the solution after chemical treatment to neutrality
The filtered filter pulp of 40g is added 960ml and is configured to the aqueous suspension that mass concentration is 0.8 wt%, by stone mortar extra-fine grinding instrument
Scale be adjusted to -8, revolving speed be 1200 r/min under grind 10 ~ 60min.
Embodiment 4
Handled using chemical treatment method: (1), weigh 100 mesh wood powder 50g and 950ml distilled water be uniformly mixed, be put into 75
Heat 3h in DEG C water-bath；(2), it is 1.5 that sodium chlorite 15g is added into acquired solution and is made into sodium chlorite mass concentration
The solution of wt%, and it is 4-5 that 2 ~ 5ml glacial acetic acid, which is added, to adjust its pH, and the Asia 15g chlorine is during which added into mixed solution every 1.5h
Sour sodium and 2 ~ 5ml glacial acetic acid solution, maintenance sodium chlorite mass concentration are 1.5 wt%, pH value 4-5；(3), solution to be mixed
Solution up to neutrality and carries out filtering acquisition filter pulp wash with distilled water after cooling；(4), filter pulp obtained in the previous step is added
Enter into NaOH aqueous slkali and dilute, NaOH concentration is 17.5 wt% in the solution after dilution, is stood at room temperature after sealing stirring
10 h；(5), the solution after processing to neutrality and filters wash with distilled water；(6), it is added into the filter pulp of acquisition
Appropriate distilled water is configured to the aqueous solution of 1000ml, is put into 75 DEG C of water-baths and heats 3h, and repeats the processing of step (2)
Process.
It is handled using the method for mechanical treatment: (1) filtering, weigh after cleaning the solution after chemical treatment to neutrality
The filtered filter pulp of 32g is added 968ml and is configured to the aqueous suspension that mass concentration is 0.7 wt%, by stone mortar extra-fine grinding instrument
Scale be adjusted to -7.5, revolving speed be 1500 r/min under grind 10 ~ 60min.
Claims (3)
1. the method that a polishing prepares II crystal type nano fiber of lignocellulosic, it is characterised in that the following steps are included:
(1) partial lignin is removed；
(2) strong base solution is handled；
(3) residual lignin is removed；
(4) a mechanical polishing；
The step (1) removes partial lignin, comprises the following steps that:
1) 1:15 in mass ratio ~ 30 weighs wood powder and distilled water, is uniformly mixed；
2) sodium chlorite is added, is made into the solution that sodium chlorite concentrations are 1-2 wt %, adds the glacial acetic acid of 2-5 vol %,
Adjusting pH value of solution is 4-5；It is put into 2 ~ 3h of heating in 73-78 DEG C of water-bath, during which adds sub- chlorine into solution every 1 ~ 1.5h
Sour sodium and glacial acetic acid, so that the concentration of sodium chlorite is maintained at 1-2 wt % in solution, solution ph is maintained at 4-5；
3) mixed solution by sodium chlorite and glacial acetic acid after processed is wash with distilled water to neutral, and vacuum filtration is not to dripping
Water obtains the filter pulp under water swollen state；
Step (2) the strong base solution processing comprises the following steps that:
1) filter pulp that step (1) processing obtains is added in NaOH aqueous slkali and is diluted, NaOH concentration is in the solution after dilution
15-19 wt% stands >=10 h after sealing stirring at room temperature；
2) acquired solution is filtered by vacuum to not dripping wash with distilled water to neutrality, obtains filter pulp；
Step (3) the removal residual lignin comprises the following steps that:
1) 1:15 in mass ratio ~ 30 weighs the filter pulp and distilled water that step (2) processing obtains, and stirs evenly, is put into 75 DEG C of water-baths
Heat 3-4.5h in pot, during which sodium chlorite and glacial acetic acid is added into solution every 1 ~ 1.5h, so that solution Central Asia chlorine
The concentration of sour sodium is maintained at 1-2 wt %, and solution ph is maintained at 4-5；
2) by acquired solution wash with distilled water to filtering after neutral, it is 0.5 ~ 1 that the filter pulp filtered, which is configured to mass concentration,
The aqueous suspension of wt%；
The mechanical polishing of the step (4), comprises the following steps that:
1) aqueous suspension that step (3) processing obtains is ground once in stone mortar extra-fine grinding instrument, revolving speed 1200-1600
R/min, time 10-60min.
2. the method that a polishing according to claim 1 prepares II crystal type nano fiber of lignocellulosic, feature
It is in step 1), the wood powder is the wood powder of 50-300 mesh.
3. the method that a polishing according to claim 2 prepares II crystal type nano fiber of lignocellulosic, feature
It is in step 1), the wood powder is replaced with bamboo powder.
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| CN103388273B (en) * | 2013-08-19 | 2015-06-03 | 南京林业大学 | Method for preparing nanometer hydrophobic paper by utilizing corrugated paper/nanometer titanium dioxide |
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Application publication date: 20180928 Assignee: Nanjing Meili Decoration Engineering Co.,Ltd. Assignor: NANJING FORESTRY University Contract record no.: X2020980005873 Denomination of invention: Preparation of lignocellulose type II nanofibers by one-step grinding method Granted publication date: 20191011 License type: Common License Record date: 20200910 |
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Application publication date: 20180928 Assignee: Nanjing Yixin Information Technology Co.,Ltd. Assignor: NANJING FORESTRY University Contract record no.: X2021980004181 Denomination of invention: Preparation of lignocellulose type II nanofibers by one-step grinding Granted publication date: 20191011 License type: Common License Record date: 20210601 |