CN109279811A - A kind of preparation method of building heat preservation heat-insulation composite material - Google Patents
A kind of preparation method of building heat preservation heat-insulation composite material Download PDFInfo
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- CN109279811A CN109279811A CN201811205901.9A CN201811205901A CN109279811A CN 109279811 A CN109279811 A CN 109279811A CN 201811205901 A CN201811205901 A CN 201811205901A CN 109279811 A CN109279811 A CN 109279811A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/04—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/023—Chemical treatment
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/10—Coating or impregnating
- C04B20/1055—Coating or impregnating with inorganic materials
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/10—Coating or impregnating
- C04B20/1055—Coating or impregnating with inorganic materials
- C04B20/1066—Oxides, Hydroxides
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/30—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values
- C04B2201/32—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values for the thermal conductivity, e.g. K-factors
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Abstract
The invention discloses a kind of preparation methods of building heat preservation heat-insulation composite material, comprising the following steps: (1) sisal fiber is made in sisal hemp leaf sheath；(2) sisal fiber is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and is pre-processed；(3) it is worth modified sisal fiber；(4) modified sisal fiber is mixed to be placed in modified epoxy maceration extract with glass fibre and impregnates, solidifies；(5) recycled polyethylene is mixed with product A, modified Nano grade calcium carbonate, diatomite, graphene oxide, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate, obtains mixture B；(6) add water into mixture B, obtain mixed slurry B；(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying.The product that the present invention is prepared mixes synergistic effect with different, can effectively improve its compression strength, flexural strength and mechanical performance energy.
Description
Technical field
The invention belongs to technical field of composite materials, and in particular to a kind of preparation side of building heat preservation heat-insulation composite material
Method.
Background technique
With environmental problem brought by worldwide energy shortages and using energy source, resource, the energy and environmental protection
It is three test for restricting mankind nowadays society and sustainable economic development, saving energy, lowering energy consumption and reducing pollutants discharge are to realize that society and economy can hold
The effective way of supervention exhibition.Other than the reasonable development of the Efficient Conversion of the energy and renewable energy, the benefit of the energy is sufficiently improved
With efficiency and energy-efficient key.Heat-insulating heat-preserving material can effectively reduce heat in generation, conveying, storage and durings use etc.
Adjoint thermal loss is widely used in the fields such as building, chemical industry, electronics, clothes, aviation day, it has also become improves energy utilization
Efficiency and the important channel for realizing saving energy, lowering energy consumption and reducing pollutants discharge.Therefore, novel light is studied, the efficient heat-insulation and heat-preservation with stable structure is answered
Condensation material, for realizing the efficient utilization, section consumption reduction emission reduction and the sustainable development of human environment and society of resource and the energy
It has very important significance.Building needs to use a variety of materials in constructing from main structure to decorations, in order to save
The energy, now higher and higher to the heat-insulation and heat-preservation requirement of house and business external wall of house, heat-insulation and heat-preservation construction material is also at each
The research and development object of a building materials manufacturer improves the heat insulation and preservation effect of conventional building materials.
Authorization Notice No. CN104496399B discloses a kind of aeroge building heat preservation heat-insulation composite material and preparation method,
This method comprises: providing the aqueous slurry containing aerosil, the aqueous slurry is mainly by aerosil
The stable dispersion system that powder, surfactant, binder and water are uniformly mixed to form；Be added into the aqueous slurry is in powder
The construction material of body shape or flow-like, and it is uniformly mixed to form mixed material；And it by the mixed material drying and moulding, obtains
Obtain the aeroge building heat preservation heat-insulation composite material.But the aeroge building heat preservation heat-insulation composite material its pressure resistance
Degree, flexural strength and bad mechanical property.
Summary of the invention
The present invention provides a kind of preparation methods of building heat preservation heat-insulation composite material, solve in above-mentioned background technique not
Foot, the building heat preservation heat-insulation composite material that the present invention is prepared mix synergistic effect with different, can effectively improve it
Compression strength, flexural strength and mechanical performance, and the inside configuration quality of composite material is easy to guarantee, outer dimension precision compared with
Height, it is applied widely.
It is of the existing technology in order to solve the problems, such as, it adopts the following technical scheme that
A kind of preparation method of building heat preservation heat-insulation composite material, includes the following steps:
(1) the sisal leaves section that sisal hemp leaf sheath is cut into 1~3cm, is put into flour mill and wears into fiber, after screening process
To 100~200 mesh particles, then under the conditions of 110 DEG C of temperature of baking oven, be dried within 24 hours；
(2) step (1) resulting product is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and carries out in advance
Processing；
(3) ball mill is added in step (2) resulting product and hard calcium acetate, nano aluminium oxide, in the case where revolving speed is 200r/min
20min is stirred, modified sisal fiber is obtained；
(4) the resulting modified sisal fiber of step (3) is uniformly mixed with glass fibre, it then will modified sisal fiber and glass
The mixture of fiber, which is placed in modified epoxy maceration extract, to be impregnated, so that modified epoxy is coated uniformly on modified sisal hemp fibre
The surface of dimension and the mixture of glass fibre, then solidified to get product A；
(5) recycled polyethylene is ground into powder, then with product A, modified Nano grade calcium carbonate, diatomite, graphite oxide
It is uniform that alkene, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate are placed in magnetic agitation in high mixer,
Obtain mixture B；
(6) add water into mixture B, until water content is 40%~50% in material, is uniformly mixed, is then slowly heated to 80
DEG C, insulation reaction 1~2 hour, obtain mixed slurry B；
(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying is to get building heat preservation heat-insulation composite material, institute
The temperature for stating extrusion forming is 100~120 DEG C, and the pressure of extrusion forming is 20~25MPa, and the process of the curing and drying is such as
Under: 50~60 DEG C are first warming up to, heated-air drying 10~20 hours, then heats to 70~80 DEG C, control air humidity is 60%,
Hot-air curing 30~40 hours, last natural curing 48~72 hours.
Preferably, step (1) resulting product is first placed in saturation Ca (OH) in the step (2)2It is soaked in solution
Bubble, then be placed in silica solution to carry out pretreated process specific as follows: first place the product in saturations Ca (OH)2It is impregnated in solution
10~14 hours, soaking temperature was 53~68 DEG C, so that sisal fiber adsorption Ca (OH)2Solution drains extra Ca (OH)2
Solution dries, then by adsorption Ca (OH)2The sisal fiber of solution impregnates in silicon dioxide gel again, impregnates 10~15
Minute, excess silicon dioxide colloidal sol glue is drained, drying makes silicon dioxide gel crosslinking curing.
Preferably, step (2) resulting product and the mass ratio of hard calcium acetate, nano aluminium oxide are in the step (3)
100:3:5。
Preferably, modified epoxy is that epoxy resin, curing agent, carbon nanotube and toughener are pressed in the step (4)
The mixed solution that weight 100:30:1:20 is mixed:.
Preferably, solidification process is as follows in the step (4): first it is warming up to 60 DEG C, heat preservation solidification 3~5 hours, then cool down
To 0~10 DEG C, heat preservation solidification 4~6 hours.
Preferably, by weight, the dosage of recycled polyethylene is 20~30 parts, the use of product A in the step (5)
Amount is 15~25 parts, the dosage of modified Nano grade calcium carbonate is 30~50 parts, 30~40 parts of the dosage of diatomite, graphene oxide
6~10 parts of dosage, 20~30 parts of the dosage of coating nano-pearl rock, 12~19 parts of the dosage of aerating aluminium powder, polyacrylamide
5~10 parts of dosage and 3~7 parts of dosage of calcium lignosulfonate.
Preferably, the modified Nano grade calcium carbonate the preparation method is as follows:
(1) by weight, 90 parts of nanometer grade calcium carbonates, 8 parts of coupling agents, 5 parts of lubricants and 3 parts of dispersing agents are weighed, it is spare；
(2) nanometer grade calcium carbonate is put in 100 DEG C of oven heat and is dried 5 hours, is cooled to room temperature, it is mixed that high speed is added after taking-up
It is stirred 10 minutes in conjunction machine, weighed coupling agent is then added and is stirred for 5 minutes, sequentially adds weighed dispersing agent and lubrication
Then agent, heating stirring are transferred to stirring in cold mixer and are cooled to≤40 DEG C of dischargings, obtain modified Nano grade calcium carbonate to 70 DEG C.
Preferably, the coating nano-pearl rock the preparation method is as follows:
Expanded perlite is soaked in the nano silicon dioxide sol prepared in advance, using vacuum impregnation absorbing process, is made
Nano silicon dioxide sol sucks in expanded perlite cavity, forms gel, after to be aging, the dry, hydrophobic by normal pressure classification
Processing forms coating nano-pearl rock.
Preferably, the rate of heat addition being slowly heated in the step (6) is 0.5 DEG C/min.
Preferably, the process of curing and drying is as follows in the step (7): first it is warming up to 55 DEG C, heated-air drying 15 hours, so
After be warming up to 75 DEG C, control air humidity is 60%, hot-air curing 35 hours, last natural curing 60 hours.
Compared with prior art, the present invention it has the advantages that
The building heat preservation heat-insulation composite material that the present invention is prepared mixes synergistic effect with different, can effectively improve it
Compression strength, flexural strength and mechanical performance, and the inside configuration quality of composite material is easy to guarantee, outer dimension precision compared with
Height, it is applied widely, specific as follows:
(1) sisal hemp leaf sheath is first worn into fiber by the present invention, is subsequently placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silicon
Colloidal sol is pre-processed, and is finally mixed with hard calcium acetate, nano aluminium oxide, and modified sisal fiber, sisal hemp after modified is made
Its fire protecting performance of fiber, tensile strength are enhanced, and good toughness and unclassified stores synergistic effect can significantly improve building
The fire protecting performance and tensile strength of heat-insulating composite material；
(2) present invention coats one layer of modified epoxy, modified epoxy resin in modified sisal fiber and fiberglass surfacing
Modified modified sisal fiber and glass fibre good waterproof performance, water resistance is strong, acts synergistically with unclassified stores, can be improved and build
The waterproofness and thermal insulation property of heat-insulating composite material are built, the adhesion strength between material is enhanced；
(3) its of the invention recycled polyethylene, receive with product A, modified Nano grade calcium carbonate, diatomite, graphene oxide, coating
It mutually acts synergistically between rice perlite, aerating aluminium powder, polyacrylamide and calcium lignosulfonate all materials, for preparing builds
It builds heat-insulating composite material and mixes synergistic effect with different, can effectively improve its thermal insulation property, compression strength, anti-folding
Intensity and mechanical performance, and the inside configuration quality of composite material is easy to guarantee；
(4) present invention uses staged curing and drying product, so that product structure internal stability, each position thermal insulation of inside configuration
Energy, mechanical strength are uniform, significantly improve the comprehensive performance of composite material；
(5) present invention is modified expanded perlite using nano silicon dioxide sol, modified expanded perlite thermal-nsulation
Performance significantly improves, and due to the good dispersion with unclassified stores of expanded perlite, significantly improves nano silica
The dispersibility of colloidal sol, so that building heat preservation heat-insulation composite material thermal insulation property improves.
Specific embodiment
Present invention will be further explained below with reference to specific examples.These embodiments are merely to illustrate the present invention and do not have to
In limiting the scope of the invention.
Embodiment 1
The present embodiment is related to a kind of preparation method of building heat preservation heat-insulation composite material, includes the following steps:
(1) the sisal leaves section that sisal hemp leaf sheath is cut into 1~3cm, is put into flour mill and wears into fiber, after screening process
To 100~200 mesh particles, then under the conditions of 110 DEG C of temperature of baking oven, be dried within 24 hours；
(2) step (1) resulting product is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and carries out in advance
Processing；
(3) ball mill is added in step (2) resulting product and hard calcium acetate, nano aluminium oxide, in the case where revolving speed is 200r/min
20min is stirred, modified sisal fiber is obtained；
(4) the resulting modified sisal fiber of step (3) is uniformly mixed with glass fibre, it then will modified sisal fiber and glass
The mixture of fiber, which is placed in modified epoxy maceration extract, to be impregnated, so that modified epoxy is coated uniformly on modified sisal hemp fibre
The surface of dimension and the mixture of glass fibre, then solidified to get product A；
(5) recycled polyethylene is ground into powder, then with product A, modified Nano grade calcium carbonate, diatomite, graphite oxide
It is uniform that alkene, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate are placed in magnetic agitation in high mixer,
Obtain mixture B；
(6) add water into mixture B, until water content is 40% in material, be uniformly mixed, be then slowly heated to 80 DEG C, protect
Temperature reaction 1 hour, obtains mixed slurry B；
(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying is to get building heat preservation heat-insulation composite material, institute
The temperature for stating extrusion forming is 100 DEG C, and the pressure of extrusion forming is 20MPa, and the process of the curing and drying is as follows: being first warming up to
50 DEG C, heated-air drying 10 hours, 70 DEG C are then heated to, control air humidity is 60%, hot-air curing 30 hours, last natural
Maintenance 48 hours.
Wherein, step (1) resulting product is first placed in saturation Ca (OH) in the step (2)2It is impregnated in solution,
It is specific as follows to be placed in the pretreated process of silica solution progress again: first place the product in saturations Ca (OH)2Immersion 10 is carried out in solution
Hour, soaking temperature is 53 DEG C, so that sisal fiber adsorption Ca (OH)2Solution drains extra Ca (OH)2Solution dries,
Then by adsorption Ca (OH)2The sisal fiber of solution impregnates in silicon dioxide gel again, impregnates 10 minutes, drains extra two
Silica sol glue, drying make silicon dioxide gel crosslinking curing.
Wherein, step (2) resulting product and the mass ratio of hard calcium acetate, nano aluminium oxide are in the step (3)
100:3:5。
Wherein, modified epoxy is epoxy resin, curing agent, carbon nanotube and toughener by weight in the step (4)
The mixed solution that amount part proportion 100:30:1:20 is mixed:.
Wherein, solidification process is as follows in the step (4): first it is warming up to 60 DEG C, heat preservation solidification 3 hours, then it is cooled to 0
DEG C, heat preservation solidification 4 hours.
Wherein, by weight, the dosage of recycled polyethylene is 20 parts in the step (5), the dosage of product A is 15
Part, the dosage of modified Nano grade calcium carbonate be 30 parts, 30 parts of the dosage of diatomite, 6 parts of the dosage of graphene oxide, coating nanometer
20 parts of the dosage of perlite, 12 parts of the dosage of aerating aluminium powder, the dosage 3 of 5 parts of the dosage of polyacrylamide and calcium lignosulfonate
Part.
Wherein, the modified Nano grade calcium carbonate the preparation method is as follows:
(1) by weight, 90 parts of nanometer grade calcium carbonates, 8 parts of coupling agents, 5 parts of lubricants and 3 parts of dispersing agents are weighed, it is spare；
(2) nanometer grade calcium carbonate is put in 100 DEG C of oven heat and is dried 5 hours, is cooled to room temperature, it is mixed that high speed is added after taking-up
It is stirred 10 minutes in conjunction machine, weighed coupling agent is then added and is stirred for 5 minutes, sequentially adds weighed dispersing agent and lubrication
Then agent, heating stirring are transferred to stirring in cold mixer and are cooled to≤40 DEG C of dischargings, obtain modified Nano grade calcium carbonate to 70 DEG C.
Wherein, the coating nano-pearl rock the preparation method is as follows:
Expanded perlite is soaked in the nano silicon dioxide sol prepared in advance, using vacuum impregnation absorbing process, is made
Nano silicon dioxide sol sucks in expanded perlite cavity, forms gel, after to be aging, the dry, hydrophobic by normal pressure classification
Processing forms coating nano-pearl rock.
Wherein, the rate of heat addition being slowly heated in the step (6) is 0.5 DEG C/min.
Embodiment 2
The present embodiment is related to a kind of preparation method of building heat preservation heat-insulation composite material, includes the following steps:
(1) the sisal leaves section that sisal hemp leaf sheath is cut into 1~3cm, is put into flour mill and wears into fiber, after screening process
To 100~200 mesh particles, then under the conditions of 110 DEG C of temperature of baking oven, be dried within 24 hours；
(2) step (1) resulting product is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and carries out in advance
Processing；
(3) ball mill is added in step (2) resulting product and hard calcium acetate, nano aluminium oxide, in the case where revolving speed is 200r/min
20min is stirred, modified sisal fiber is obtained；
(4) the resulting modified sisal fiber of step (3) is uniformly mixed with glass fibre, it then will modified sisal fiber and glass
The mixture of fiber, which is placed in modified epoxy maceration extract, to be impregnated, so that modified epoxy is coated uniformly on modified sisal hemp fibre
The surface of dimension and the mixture of glass fibre, then solidified to get product A；
(5) recycled polyethylene is ground into powder, then with product A, modified Nano grade calcium carbonate, diatomite, graphite oxide
It is uniform that alkene, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate are placed in magnetic agitation in high mixer,
Obtain mixture B；
(6) add water into mixture B, until water content is 50% in material, be uniformly mixed, be then slowly heated to 80 DEG C, protect
Temperature reaction 2 hours, obtains mixed slurry B；
(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying is to get building heat preservation heat-insulation composite material, institute
The temperature for stating extrusion forming is 120 DEG C, and the pressure of extrusion forming is 25MPa, and the process of the curing and drying is as follows: being first warming up to
60 DEG C, heated-air drying 20 hours, 80 DEG C are then heated to, control air humidity is 60%, hot-air curing 40 hours, last natural
Maintenance 72 hours.
Wherein, step (1) resulting product is first placed in saturation Ca (OH) in the step (2)2It is impregnated in solution,
It is specific as follows to be placed in the pretreated process of silica solution progress again: first place the product in saturations Ca (OH)2Immersion 14 is carried out in solution
Hour, soaking temperature is 68 DEG C, so that sisal fiber adsorption Ca (OH)2Solution drains extra Ca (OH)2Solution dries,
Then by adsorption Ca (OH)2The sisal fiber of solution impregnates in silicon dioxide gel again, impregnates 15 minutes, drains extra two
Silica sol glue, drying make silicon dioxide gel crosslinking curing.
Wherein, step (2) resulting product and the mass ratio of hard calcium acetate, nano aluminium oxide are in the step (3)
100:3:5。
Wherein, modified epoxy is epoxy resin, curing agent, carbon nanotube and toughener by weight in the step (4)
The mixed solution that amount part proportion 100:30:1:20 is mixed:.
Wherein, solidification process is as follows in the step (4): first it is warming up to 60 DEG C, heat preservation solidification 5 hours, then it is cooled to 10
DEG C, heat preservation solidification 6 hours.
Wherein, by weight, the dosage of recycled polyethylene is 30 parts in the step (5), the dosage of product A is 25
Part, the dosage of modified Nano grade calcium carbonate be 50 parts, 40 parts of the dosage of diatomite, 10 parts of the dosage of graphene oxide, coating are received
Rice 30 parts of the dosage of perlite, 19 parts of the dosage of aerating aluminium powder, the use of 10 parts of the dosage of polyacrylamide and calcium lignosulfonate
7 parts of amount.
Wherein, the modified Nano grade calcium carbonate the preparation method is as follows:
(1) by weight, 90 parts of nanometer grade calcium carbonates, 8 parts of coupling agents, 5 parts of lubricants and 3 parts of dispersing agents are weighed, it is spare；
(2) nanometer grade calcium carbonate is put in 100 DEG C of oven heat and is dried 5 hours, is cooled to room temperature, it is mixed that high speed is added after taking-up
It is stirred 10 minutes in conjunction machine, weighed coupling agent is then added and is stirred for 5 minutes, sequentially adds weighed dispersing agent and lubrication
Then agent, heating stirring are transferred to stirring in cold mixer and are cooled to≤40 DEG C of dischargings, obtain modified Nano grade calcium carbonate to 70 DEG C.
Wherein, the coating nano-pearl rock the preparation method is as follows:
Expanded perlite is soaked in the nano silicon dioxide sol prepared in advance, using vacuum impregnation absorbing process, is made
Nano silicon dioxide sol sucks in expanded perlite cavity, forms gel, after to be aging, the dry, hydrophobic by normal pressure classification
Processing forms coating nano-pearl rock.
Wherein, the rate of heat addition being slowly heated in the step (6) is 0.5 DEG C/min.
Embodiment 3
The present embodiment is related to a kind of preparation method of building heat preservation heat-insulation composite material, includes the following steps:
(1) the sisal leaves section that sisal hemp leaf sheath is cut into 1~3cm, is put into flour mill and wears into fiber, after screening process
To 100~200 mesh particles, then under the conditions of 110 DEG C of temperature of baking oven, be dried within 24 hours；
(2) step (1) resulting product is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and carries out in advance
Processing；
(3) ball mill is added in step (2) resulting product and hard calcium acetate, nano aluminium oxide, in the case where revolving speed is 200r/min
20min is stirred, modified sisal fiber is obtained；
(4) the resulting modified sisal fiber of step (3) is uniformly mixed with glass fibre, it then will modified sisal fiber and glass
The mixture of fiber, which is placed in modified epoxy maceration extract, to be impregnated, so that modified epoxy is coated uniformly on modified sisal hemp fibre
The surface of dimension and the mixture of glass fibre, then solidified to get product A；
(5) recycled polyethylene is ground into powder, then with product A, modified Nano grade calcium carbonate, diatomite, graphite oxide
It is uniform that alkene, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate are placed in magnetic agitation in high mixer,
Obtain mixture B；
(6) add water into mixture B, until water content is 45% in material, be uniformly mixed, be then slowly heated to 80 DEG C, protect
Temperature reaction 1.5 hours, obtains mixed slurry B；
(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying is to get building heat preservation heat-insulation composite material, institute
The temperature for stating extrusion forming is 110 DEG C, and the pressure of extrusion forming is 23MPa, and the process of the curing and drying is as follows: being first warming up to
55 DEG C, heated-air drying 15 hours, 75 DEG C are then heated to, control air humidity is 60%, hot-air curing 35 hours, last natural
Maintenance 60 hours.
Wherein, step (1) resulting product is first placed in saturation Ca (OH) in the step (2)2It is impregnated in solution,
It is specific as follows to be placed in the pretreated process of silica solution progress again: first place the product in saturations Ca (OH)2Immersion 12 is carried out in solution
Hour, soaking temperature is 60 DEG C, so that sisal fiber adsorption Ca (OH)2Solution drains extra Ca (OH)2Solution dries,
Then by adsorption Ca (OH)2The sisal fiber of solution impregnates in silicon dioxide gel again, impregnates 13 minutes, drains extra two
Silica sol glue, drying make silicon dioxide gel crosslinking curing.
Wherein, step (2) resulting product and the mass ratio of hard calcium acetate, nano aluminium oxide are in the step (3)
100:3:5。
Wherein, modified epoxy is epoxy resin, curing agent, carbon nanotube and toughener by weight in the step (4)
The mixed solution that amount part proportion 100:30:1:20 is mixed:.
Wherein, solidification process is as follows in the step (4): first it is warming up to 60 DEG C, heat preservation solidification 4 hours, then it is cooled to 5
DEG C, heat preservation solidification 5 hours.
Wherein, by weight, the dosage of recycled polyethylene is 25 parts in the step (5), the dosage of product A is 20
Part, the dosage of modified Nano grade calcium carbonate be 40 parts, 35 parts of the dosage of diatomite, 8 parts of the dosage of graphene oxide, coating nanometer
25 parts of the dosage of perlite, 17 parts of the dosage of aerating aluminium powder, the dosage 4 of 6 parts of the dosage of polyacrylamide and calcium lignosulfonate
Part.
Wherein, the modified Nano grade calcium carbonate the preparation method is as follows:
(1) by weight, 90 parts of nanometer grade calcium carbonates, 8 parts of coupling agents, 5 parts of lubricants and 3 parts of dispersing agents are weighed, it is spare；
(2) nanometer grade calcium carbonate is put in 100 DEG C of oven heat and is dried 5 hours, is cooled to room temperature, it is mixed that high speed is added after taking-up
It is stirred 10 minutes in conjunction machine, weighed coupling agent is then added and is stirred for 5 minutes, sequentially adds weighed dispersing agent and lubrication
Then agent, heating stirring are transferred to stirring in cold mixer and are cooled to≤40 DEG C of dischargings, obtain modified Nano grade calcium carbonate to 70 DEG C.
Wherein, the coating nano-pearl rock the preparation method is as follows:
Expanded perlite is soaked in the nano silicon dioxide sol prepared in advance, using vacuum impregnation absorbing process, is made
Nano silicon dioxide sol sucks in expanded perlite cavity, forms gel, after to be aging, the dry, hydrophobic by normal pressure classification
Processing forms coating nano-pearl rock.
Wherein, the rate of heat addition being slowly heated in the step (6) is 0.5 DEG C/min.
Comparative example 1
A kind of aeroge building heat preservation heat-insulation composite material of Authorization Notice No. CN104496399B bulletin.
Comparative example 2
Processing is not modified to sisal fiber, i.e., does not include step (2) and step (3), remaining step and embodiment 3 are identical.
Comparative example 3
Curing and drying is not carried out to product using staged curing and drying mode, i.e., replaces step in such a way that isothermal curing is dry
Suddenly the curing and drying mode in (7), remaining step and embodiment 3 are identical.
It respectively prepared by Examples 1 to 5, comparative example 1~3 using same testing standard, in identical test environment
The performance of obtained construction material, test result such as Tables 1 and 2:
Table 1:
From above table as can be seen that composite material described in Examples 1 to 3 is substantially better than comparative example 1, matrix is as follows:
(1) the thermal conductivity mean value of composite material described in Examples 1 to 3 is 0.044W/m ﹒ k, is reduced than comparative example 1
37.14%, complex material heat preservation performance of the present invention improves；
(2) the compression strength mean value of composite material described in Examples 1 to 3 is compared with comparative example 1 for 27.67MPa and is improved
38.33%；
(3) the tensile strength mean value of composite material described in Examples 1 to 3 is compared with comparative example 1 for 2.13MPa and is improved
93.94%；
(4) the shear strength mean value of composite material described in Examples 1 to 3 is compared with comparative example 1 for 2.93MPa and is improved
39.68%。
Table 2
From above table it is found that
(1) comparative example 2 is compared with embodiment 3 and is not modified to sisal fiber, so that joint product made from comparative example 2 is anti-
Compressive Strength, tensile strength significantly reduce；
(2) comparative example 3 is compared with embodiment 3 is not dried product by the way of staged curing and drying, globality
It can reduce.
In conclusion the building heat preservation heat-insulation composite material that the present invention is prepared mixes synergistic effect with different,
It can effectively improve its compression strength, flexural strength and mechanical performance, and the inside configuration quality of composite material is easy to guarantee,
Outer dimension precision is higher, applied widely, specific as follows:
(1) sisal hemp leaf sheath is first worn into fiber by the present invention, is subsequently placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silicon
Colloidal sol is pre-processed, and is finally mixed with hard calcium acetate, nano aluminium oxide, and modified sisal fiber, sisal hemp after modified is made
Its fire protecting performance of fiber, tensile strength are enhanced, and good toughness and unclassified stores synergistic effect can significantly improve building
The fire protecting performance and tensile strength of heat-insulating composite material；
(2) present invention coats one layer of modified epoxy, modified epoxy resin in modified sisal fiber and fiberglass surfacing
Modified modified sisal fiber and glass fibre good waterproof performance, water resistance is strong, acts synergistically with unclassified stores, can be improved and build
The waterproofness and thermal insulation property of heat-insulating composite material are built, the adhesion strength between material is enhanced；
(3) its of the invention recycled polyethylene, receive with product A, modified Nano grade calcium carbonate, diatomite, graphene oxide, coating
It mutually acts synergistically between rice perlite, aerating aluminium powder, polyacrylamide and calcium lignosulfonate all materials, for preparing builds
It builds heat-insulating composite material and mixes synergistic effect with different, can effectively improve its thermal insulation property, compression strength, anti-folding
Intensity and mechanical performance, and the inside configuration quality of composite material is easy to guarantee；
(4) present invention uses staged curing and drying product, so that product structure internal stability, each position thermal insulation of inside configuration
Energy, mechanical strength are uniform, significantly improve the comprehensive performance of composite material；
(5) present invention is modified expanded perlite using nano silicon dioxide sol, modified expanded perlite thermal-nsulation
Performance significantly improves, and due to the good dispersion with unclassified stores of expanded perlite, significantly improves nano silica
The dispersibility of colloidal sol, so that building heat preservation heat-insulation composite material thermal insulation property improves.
Specific embodiments of the present invention are described above.It is to be appreciated that the invention is not limited to above-mentioned
Particular implementation, those skilled in the art can make various deformations or amendments within the scope of the claims, this not shadow
Ring substantive content of the invention.
Claims (10)
1. a kind of preparation method of building heat preservation heat-insulation composite material, which comprises the steps of:
(1) the sisal leaves section that sisal hemp leaf sheath is cut into 1~3cm, is put into flour mill and wears into fiber, after screening process
To 100~200 mesh particles, then under the conditions of 110 DEG C of temperature of baking oven, be dried within 24 hours；
(2) step (1) resulting product is first placed in saturation Ca (OH)2It is impregnated in solution, then is placed in silica solution and is located in advance
Reason；
(3) ball mill is added in step (2) resulting product and hard calcium acetate, nano aluminium oxide, in the case where revolving speed is 200r/min
20min is stirred, modified sisal fiber is obtained；
(4) the resulting modified sisal fiber of step (3) is uniformly mixed with glass fibre, it then will modified sisal fiber and glass
The mixture of fiber, which is placed in modified epoxy maceration extract, to be impregnated, so that modified epoxy is coated uniformly on modified sisal hemp fibre
The surface of dimension and the mixture of glass fibre, then solidified to get product A；
(5) recycled polyethylene is ground into powder, then with product A, modified Nano grade calcium carbonate, diatomite, graphite oxide
It is uniform that alkene, coating nano-pearl rock, aerating aluminium powder, polyacrylamide and calcium lignosulfonate are placed in magnetic agitation in high mixer,
Obtain mixture B；
(6) add water into mixture B, until water content is 40%~50% in material, is uniformly mixed, is then slowly heated to 80
DEG C, insulation reaction 1~2 hour, obtain mixed slurry B；
(7) mixed slurry B is placed in extrusion forming in mold, then curing and drying is to get building heat preservation heat-insulation composite material, institute
The temperature for stating extrusion forming is 100~120 DEG C, and the pressure of extrusion forming is 20~25MPa, and the process of the curing and drying is such as
Under: 50~60 DEG C are first warming up to, heated-air drying 10~20 hours, then heats to 70~80 DEG C, control air humidity is 60%,
Hot-air curing 30~40 hours, last natural curing 48~72 hours.
2. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (2)
It is middle that step (1) resulting product is first placed in saturation Ca (OH)2Impregnated in solution, then be placed in silica solution carry out it is pretreated
Process is specific as follows: first place the product in saturations Ca (OH)2It is carried out in solution immersion 10~14 hours, soaking temperature is 53~68
DEG C, so that sisal fiber adsorption Ca (OH)2Solution drains extra Ca (OH)2Solution dries, then by adsorption Ca
(OH)2The sisal fiber of solution impregnates in silicon dioxide gel again, impregnates 10~15 minutes, drains excess silicon dioxide colloidal sol
Glue, drying make silicon dioxide gel crosslinking curing.
3. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (3)
The mass ratio of the resulting product of middle step (2) and hard calcium acetate, nano aluminium oxide is 100:3:5.
4. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (4)
Middle modified epoxy be epoxy resin, curing agent, carbon nanotube mixed with toughener 100:30:1:20 by weight ratio and
At mixed solution:.
5. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (4)
Middle solidification process is as follows: first it is warming up to 60 DEG C, heat preservation solidification 3~5 hours, then it is cooled to 0~10 DEG C, heat preservation solidification 4~6 is small
When.
6. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that by weight,
The dosage of recycled polyethylene is 20~30 parts in the step (5), the dosage of product A is 15~25 parts, modified Nano grade carbon
The dosage of sour calcium is 30~50 parts, 30~40 parts of the dosage of diatomite, 6~10 parts of the dosage of graphene oxide, coating nanometer are precious
20~30 parts of dosage, 12~19 parts of the dosage of aerating aluminium powder, 5~10 parts of the dosage of polyacrylamide and the lignin sulfonic acid of Zhu Yan
3~7 parts of the dosage of calcium.
7. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the modified Nano
Grade calcium carbonate the preparation method is as follows:
(1) by weight, 90 parts of nanometer grade calcium carbonates, 8 parts of coupling agents, 5 parts of lubricants and 3 parts of dispersing agents are weighed, it is spare；
(2) nanometer grade calcium carbonate is put in 100 DEG C of oven heat and is dried 5 hours, is cooled to room temperature, it is mixed that high speed is added after taking-up
It is stirred 10 minutes in conjunction machine, weighed coupling agent is then added and is stirred for 5 minutes, sequentially adds weighed dispersing agent and lubrication
Then agent, heating stirring are transferred to stirring in cold mixer and are cooled to≤40 DEG C of dischargings, obtain modified Nano grade calcium carbonate to 70 DEG C.
8. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the coating nanometer
Perlite the preparation method is as follows:
Expanded perlite is soaked in the nano silicon dioxide sol prepared in advance, using vacuum impregnation absorbing process, is made
Nano silicon dioxide sol sucks in expanded perlite cavity, forms gel, after to be aging, the dry, hydrophobic by normal pressure classification
Processing forms coating nano-pearl rock.
9. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (6)
The rate of heat addition of middle slow heating is 0.5 DEG C/min.
10. the preparation method of building heat preservation heat-insulation composite material according to claim 1, which is characterized in that the step (7)
The process of middle curing and drying is as follows: being first warming up to 55 DEG C, heated-air drying 15 hours, then heats to 75 DEG C, control air humidity
It is 60%, hot-air curing 35 hours, last natural curing 60 hours.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109650845A (en) * | 2019-02-28 | 2019-04-19 | 常州工学院 | A method of it preparing Nano particles of silicon dioxide-graphene oxide-plant fiber object and closes object |
| CN114621018A (en) * | 2022-04-13 | 2022-06-14 | 新密市豫源耐火材料有限公司 | Manufacturing process of light acid-resistant anticorrosive castable |
| WO2022133557A1 (en) * | 2020-12-25 | 2022-06-30 | Neves Monteiro Sergio | Optimization of multilayer armor system of epoxy matrix composite with sisal fabric functioned with graphene oxide |
| CN115182200A (en) * | 2022-06-16 | 2022-10-14 | 浙江夏王纸业有限公司 | Controllable-expansion-rate decorative base paper and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102617984A (en) * | 2011-01-26 | 2012-08-01 | 中国科学院理化技术研究所 | Modified epoxy resin base material and modified epoxy resin matrix composite material |
| CN103628307A (en) * | 2013-12-11 | 2014-03-12 | 山东科技大学 | Method for improving heat resistance of sisal fibers |
| CN104529301A (en) * | 2014-12-23 | 2015-04-22 | 太原理工大学 | Nano-perlite-containing building thermal insulation concrete and preparation method thereof |
| KR101624480B1 (en) * | 2014-11-14 | 2016-05-25 | 엔에프에스(주) | The method of flame resistance styrofoam |
| CN108358508A (en) * | 2018-05-07 | 2018-08-03 | 合肥金同维低温科技有限公司 | A kind of novel energy saving thermal insulation material and preparation method thereof |
-
2018
- 2018-10-17 CN CN201811205901.9A patent/CN109279811A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102617984A (en) * | 2011-01-26 | 2012-08-01 | 中国科学院理化技术研究所 | Modified epoxy resin base material and modified epoxy resin matrix composite material |
| CN103628307A (en) * | 2013-12-11 | 2014-03-12 | 山东科技大学 | Method for improving heat resistance of sisal fibers |
| KR101624480B1 (en) * | 2014-11-14 | 2016-05-25 | 엔에프에스(주) | The method of flame resistance styrofoam |
| CN104529301A (en) * | 2014-12-23 | 2015-04-22 | 太原理工大学 | Nano-perlite-containing building thermal insulation concrete and preparation method thereof |
| CN108358508A (en) * | 2018-05-07 | 2018-08-03 | 合肥金同维低温科技有限公司 | A kind of novel energy saving thermal insulation material and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 混凝土外加剂及其应用技术论坛编: "《聚羧酸系高性能减水剂及其应用技术新进展》", 31 May 2015, 北京理工大学出版社 * |
| 王善勤等: "《塑料配方设计问答》", 31 January 2003, 中国轻工业出版社 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109650845A (en) * | 2019-02-28 | 2019-04-19 | 常州工学院 | A method of it preparing Nano particles of silicon dioxide-graphene oxide-plant fiber object and closes object |
| CN109650845B (en) * | 2019-02-28 | 2021-03-12 | 常州工学院 | Method for preparing silicon dioxide nanoparticle-graphene oxide-plant fiber compound |
| WO2022133557A1 (en) * | 2020-12-25 | 2022-06-30 | Neves Monteiro Sergio | Optimization of multilayer armor system of epoxy matrix composite with sisal fabric functioned with graphene oxide |
| CN114621018A (en) * | 2022-04-13 | 2022-06-14 | 新密市豫源耐火材料有限公司 | Manufacturing process of light acid-resistant anticorrosive castable |
| CN115182200A (en) * | 2022-06-16 | 2022-10-14 | 浙江夏王纸业有限公司 | Controllable-expansion-rate decorative base paper and preparation method thereof |
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