CN111187448B

CN111187448B - Oil shale semicoke-based composite flame retardant, preparation method thereof and application thereof in high polymer material

Info

Publication number: CN111187448B
Application number: CN202010095349.3A
Authority: CN
Inventors: 张哲�; 靳亚娥; 杜育峰; 丰鹏; 张炳忠; 袁崇亮; 许继宗; 杨志旺
Original assignee: Baiyin Division Innovation Research Institute Of Northwest Normal University; Yaojie Coal Electricity Group Co ltd; Northwest Normal University
Current assignee: Baiyin Division Innovation Research Institute Of Northwest Normal University; Yaojie Coal Electricity Group Co ltd; Northwest Normal University
Priority date: 2020-02-17
Filing date: 2020-02-17
Publication date: 2021-09-03
Anticipated expiration: 2040-02-17
Also published as: CN111187448A

Abstract

The invention discloses an oil shale semicoke-based composite flame retardant, which mainly comprises oil shale semicoke, attapulgite and montmorillonite, wherein the oil shale semicoke, the attapulgite and the montmorillonite are subjected to surface modification treatment by a compound A; the chemical structural formula of the compound A is as follows:

Description

Oil shale semicoke-based composite flame retardant, preparation method thereof and application thereof in high polymer material

Technical Field

The invention belongs to the field of high polymer material additives, and particularly relates to an oil shale semicoke-based composite flame retardant.

Background

(1) Current application of oil shale semicoke

The oil shale of the national standard has abundant resources and high oil content, and can supplement petroleum resources by refining shale oil, so that the method is a new energy source with a very promising prospect. The oil shale semicoke can be generated in the process of refining shale oil from oil shale, if the oil shale is stacked for a long time, the environment is polluted, land resources are occupied, and the research and development of the resource utilization technology of the oil shale semicoke have great value and development prospect. The oil shale semicoke is composed primarily of inorganic oxides (e.g., kaolin clay) and residual carbon components. At present, the method is mainly applied to traditional industries such as calcium carbide, chemical fertilizer, ferroalloy, industry and civil combustion. With the increasingly strict requirements on the product quality such as national industry upgrading and the like, the downstream market demand of the oil shale semicoke is limited, and meanwhile, the oil shale semicoke contains a certain amount of water-soluble phenols, sulfides and the like, so that serious environmental pollution can be caused by accumulation and storage, and the development of new oil shale semicoke application becomes a focus of attention.

In recent years, the application of the oil shale semicoke becomes a hot spot, and the comprehensive search of Chinese and foreign documents shows that the application research of the oil shale semicoke is mainly focused on the following fields:

first, the adsorbent is prepared from oil shale semicoke. In the latest reported chinese patent CN 110523373 a, a preparation method of an oil shale semi-coke adsorbent is disclosed, in which agroforestry biomass waste is washed, dried and crushed, and then uniformly mixed with oil shale semi-coke powder, the mixture is added into an activating agent for activation treatment, then the mixture is calcined and carbonized under the protection of nitrogen, and finally the oil shale semi-coke efficient adsorbent product is obtained by acid washing, water washing, drying and crushing. According to the invention, the agriculture and forestry biomass waste is doped into the oil shale semicoke to prepare the charcoal/oil shale semicoke adsorbent, so that the charcoal content of the oil shale semicoke is increased, the specific surface area is increased, the adsorption performance of the semicoke is effectively improved, the product can realize adsorption of various pollutants, and the charcoal/oil shale semicoke adsorbent can be widely applied to multiple fields of water body purification, soil pollution treatment and the like.

Secondly, the composite material is used in building materials, such as cement additives, insulation boards, ceramic particles and the like. The literature, "application research of cement partially substituted by shale ash in cement mortar" (Fan Rui et al, Jilin building university college of traffic science and engineering) reports that the influence of the cement partially substituted by shale semicoke and power plant ash in Betulan city of Jilin province on initial and final setting time and the compressive strength and the flexural strength of the cement mortar is researched through experiments. The two kinds of oil shale ash residues respectively replace cement by 10%, 20% and 30% of doping amount, and tests show that: the influence of the oil shale semicoke on the initial and final setting time is not obvious, and the power plant ash can prolong the initial and final setting time of cement paste; the oil shale semicoke has obvious influence on the early breaking strength of the cement mortar, and the breaking strength can be obviously reduced; the influence on the later strength is small. The power plant ash has no obvious influence on the early strength of the cement mortar, and the flexural strength of the cement mortar is improved when the mixing amount reaches 20 percent, so that the cement mortar has the performance of improving the flexural strength; the two kinds of oil shale ash can reduce the compressive strength of cement mortar, and the influence of ash in a power plant is small. The authors demonstrated that oil shale carbocoal can be used in cement in moderate amounts.

Thirdly, white carbon black (white silica nanomaterial) is prepared. Chinese patent CN201910672724.3 reports a method for preparing a white silica nano material by using oil shale semi-coke, which is to crush the oil shale semi-coke into powder and then mix the powder with sodium carbonate solid powder uniformly; adding deionized water into the mixture, pressing the mixture into sheets by using a roll-to-roll machine, and calcining the sheets for 2 to 4 hours at the temperature of between 400 and 800 ℃ in an air atmosphere to obtain a solid product A; then uniformly dispersing the solid product A into a mixed acid water solution, and stirring and reacting for 2-12 h at 50-90 ℃; performing centrifugal separation to obtain a solid product B; and finally, calcining the solid product B at 500-900 ℃ for 1-2 h to obtain a white nano silicon oxide product. The preparation method has the advantages of simple and efficient preparation process, high whiteness and good dispersibility of the product, and has wide application prospects in the fields of high polymer material reinforcement, functional carriers, heat insulation materials, rubber fillers, hybrid pigments, inorganic antibacterial materials and the like. The great-continental-studios university jade ring reports a paper of 'research on preparation of white carbon black and modification of oil shale residues', and experimental results show that raw materials suitable for preparing the white carbon black are Longkou oil shale dry distillation semicoke, Bechdian oil shale dry distillation semicoke and Bechdian oil shale smoothing furnace dry flow semicoke, while white carbon black prepared from fine slag of a Bechdian oil shale thermal power plant cannot meet national indexes, and can be used for cement blending, brick making and the like. The white carbon black prepared from the dry distillation semicoke contains about 30% of silicon dioxide crystals, and the white carbon black with lower crystallinity is obtained through separation, so that a foundation is laid for realizing industrialization of producing the white carbon black by using the oil shale dry distillation semicoke, the problem of accumulation of industrial waste is solved, a low-cost white carbon black production method is provided, comprehensive utilization of resources is realized, and good economic, environmental-friendly and social benefits are achieved.

Fourthly, the fuel is used. This is the most common application method at present, and there are very many reports in the literature. However, when used as a fuel, the fuel has a low combustion value and causes secondary pollution.

Fifthly, the oil shale semi-coke is applied as a high polymer material additive in plastics and rubber. Chinese patent CN 110183684A reports a modified oil shale semicoke, a preparation method thereof and application thereof in high polymer materials, wherein the modified shale semicoke is the oil shale semicoke with the surface grafted with sulfanilamide groups. By including: (1) reacting the oil shale semicoke with a silane coupling agent in an aqueous medium to obtain silane coupling agent modified oil shale semicoke; (2) and reacting the oil shale semicoke modified by the silane coupling agent with sulfanilamide chloride to obtain the modified oil shale semicoke. Compared with the existing oil shale semi-coke, the modified oil shale semi-coke of the invention can obviously improve the mechanical property, the flame retardance, the smoke suppression, the weather resistance and the insulating property of a high polymer material, and reduce the toxicity of smoke, thus being an excellent high polymer material additive.

Chinese patent CN 110054812A discloses a method for preparing rubber by using oil shale as a filler, relating to a method for preparing rubber, which comprises the following steps of 1) putting natural rubber into an open mill to be pressed into sheets. Then zinc oxide, stearic acid, an anti-aging agent, an accelerator, oil shale and sulfur are added in sequence; 2) and putting the mixed natural rubber material into a flat vulcanizing machine for vulcanization molding. The tensile strength performance of the modified rubber obtained by the invention is close to that of a product taking white carbon black as a filler, and is better than that of a product taking heavy calcium carbonate powder as a filler.

(2) Application status quo of attapulgite in flame retardant field

Attapulgite, also known as palygorskite, is widely used in flame retardation of high molecular materials at present. Through literature search, the earliest globally published patent of attapulgite as a flame retardant is Chinese patent CN200510041656.9, and the invention provides a flame-retardant polypropylene composite material which is prepared by mixing and refining a palygorskite compound flame retardant and polypropylene at the temperature of between 80 and 300 ℃. Because of the microporous structure of the palygorskite, the flame-retardant polypropylene composite material manufactured by the invention has the characteristics of high efficiency, low price, low toxicity, low smoke, no environmental pollution, good thermal stability and the like, and has good machining performance. In recent years, 2856 patents which disclose that attapulgite is used as a flame retardant or smoke suppressant, and the particularity and hot spot of the material in the flame retardant and smoke suppressant field can be seen.

(3) Application status quo of montmorillonite in flame retardant field

The study of montmorillonite in the field of flame retardation and smoke suppression is early, and early researchers mainly study the intercalation modification of montmorillonite and the influence on the performance of high polymer materials. The first domestic patent on the specific research on the influence of montmorillonite on the flame retardant property of a high polymer material is CN200410050993.X, the invention relates to a preparation method of a polyolefin/montmorillonite nano non-halogen flame retardant material, unmodified montmorillonite and a polar group-containing vinyl monomer are used to carry out in-situ reaction under the processing condition of the polyolefin non-halogen flame retardant material to form the polyolefin/montmorillonite nano non-halogen flame retardant material with an intercalation structure, the barrier effect and the nano effect of the montmorillonite intercalation structure have the synergistic effect on the flame retardant property of the existing polyolefin non-halogen flame retardant material and also have the compensation effect on the loss of the mechanical property and the processing property of the existing polyolefin non-halogen flame retardant material, and the compatibility of the non-halogen flame retardant agent and the montmorillonite with polyolefin resin can be structurally improved in the in-situ reaction process. The invention not only overcomes the defect that organic montmorillonite modified by organic intercalation agent is needed when the existing polymer/montmorillonite nano composite material is prepared, but also overcomes the defect that the mechanical property and the processing property of polyolefin are damaged when non-halogen flame retardant is added to prepare the polyolefin non-halogen flame retardant material. Later, the montmorillonite is used as a flame-retardant auxiliary agent, and the montmorillonite is also a good high-molecular flame-retardant auxiliary agent.

The background research shows that oil shale semicoke, attapulgite, montmorillonite and the like can be used as flame retardants to improve the oxygen index of the polymer composite material, but all the reports in the literature show that the flame retardants are in the form of auxiliary materials, and the flame retardants are still mainly common phosphorus-nitrogen series and inorganic hydroxide series. The application mode can not utilize a large amount of oil shale semicoke waste, and has no obvious effect on solving the problem of solid waste of the oil shale.

Disclosure of Invention

Based on the prior art, the invention aims to provide the oil shale semicoke-based composite flame retardant.

In order to achieve the purpose, the invention adopts the following technical scheme:

an oil shale semicoke-based composite flame retardant mainly comprises oil shale semicoke, attapulgite and montmorillonite, wherein the oil shale semicoke, the attapulgite and the montmorillonite are subjected to surface modification treatment by a compound A;

the chemical structural formula of the compound A is as follows:

preferably, the content of the oil shale semicoke is 70-98%, the content of the attapulgite is 1-29% and the content of the montmorillonite is 1-29% based on the total mass of the oil shale semicoke, the attapulgite and the montmorillonite.

The preparation method of the oil shale semicoke-based composite flame retardant comprises the following steps: mixing and reacting the oil shale semicoke, the attapulgite, the montmorillonite and the compound A in a water phase to obtain the oil shale semicoke-based composite flame retardant.

Preferably, the addition amount of the compound A is 2-10% of the total mass of the oil shale semicoke, the attapulgite and the montmorillonite.

Preferably, the reaction temperature is controlled between 80 ℃ and 120 ℃, and the reaction time is 1-4 hours. Ultrasonic treatment is adopted during reaction, so that inorganic powder oil shale semi-coke, attapulgite and montmorillonite can be embedded into each other to form a certain load structure.

The compound A is grafted to the surfaces of oil shale semicoke, attapulgite and montmorillonite, so that the compatibility between inorganic powder and high molecular polymers can be well improved, and a certain flame-retardant synergistic effect is achieved. Phosphate radical, carboxyl and the like contained in the compound A chemically react with hydroxyl on the surfaces of the oil shale semi-coke, the attapulgite and the montmorillonite to form covalent bonds or form non-covalent bonds by utilizing Van der Waals force, so that the three inorganic powders are interpenetrated and embedded more firmly, the contact force between the mixed powder and a polymer matrix is enhanced, and the improvement of the mechanical property is beneficial.

The flame retardant has good universality, and is not only suitable for resins such as polypropylene, polyethylene, EVA, ABS, polycarbonate, various nylon, aramid fiber and the like, but also suitable for various rubbers, coatings and adhesives.

The flame retardant composite of the invention not only has flame retardant property obviously superior to that of magnesium hydroxide, but also can obviously improve the mechanical property of high polymer materials.

Drawings

FIG. 1 is a scanning electron micrograph of the composite flame retardant described in example 1.

FIG. 2 is an elemental analysis of the composite flame retardant described in example 1.

Detailed Description

The present invention will be described in further detail with reference to the following examples and the accompanying drawings.

Example 1

Oil shale semicoke (provided by Yaojie coal and Electricity group Co., Ltd.), attapulgite (provided by Jiangsu Jinhan New Material Co., Ltd.), montmorillonite (commercially available) and a compound A (

CAS: 936234-33-2, commercially available) are compounded according to the mass ratio of 95:2:3:5, then distilled water is used for preparing slurry with the mass concentration of 20% -45%, high temperature (80-120 ℃), high pressure homogenization and ultrasonic reaction are carried out for 2 hours, centrifugal dehydration is carried out, then mixed solvent of ethanol and water is used for repeatedly washing for 5 times, washed paste is prepared into 20% slurry, spray drying is carried out at 120 ℃, the particle size D97 of powder is controlled to be not less than 1500 meshes, and the compound A surface modified composite flame retardant is prepared.

The appearance structure and the element components of the composite flame retardant are characterized by utilizing a scanning electron microscope, the result is shown in figure 1-2, and the appearance characterization shows that three inorganic powders, namely oil shale semicoke, montmorillonite and attapulgite are embedded into each other to form a certain load structure instead of being simply mixed; secondly, elemental analysis shows that although the flame retardant still contains a certain phosphorus element after being washed for many times, the conclusion that the compound A is grafted to the surface of an inorganic substance can be proved by the improvement of mechanical properties after the composite material is added.

According to the preparation process, the following comparative powder samples are respectively prepared, and the raw materials of each powder sample are proportioned in parts by weight as follows:

	oil shale semicoke	Attapulgite	Montmorillonite clay	Compound A
					Composite flame retardant	95	2	3	5
Powder sample 2	95	2	3	0
					Powder sample 3	100	0	0	5
Powder sample 4	0	100	0	5
					Powder sample 5	0	0	100	5
Powder sample 6	95	0	5	5
					Powder sample 7	95	5	0	5
Powder sample 8	0	40	60	5

Performance testing

The invention selects representative ethylene-vinyl acetate copolymer (EVA) which is large in market usage amount at present as a matrix to examine the performance of each powder sample.

The formula (parts by weight) is as follows:

comparative sample 1: ultrafine magnesium hydroxide was used, without compound a.

Comparative sample 9: the superfine magnesium hydroxide is subjected to surface modification by the compound A, and the preparation process is different from the composite flame retardant in the embodiment 1 only in that the oil shale semicoke, the montmorillonite and the attapulgite are completely replaced by the superfine magnesium hydroxide.

According to the formula dosage, EVA, a powder sample, superfine magnesium hydroxide, an antioxidant, a plasticizer and a compatilizer are mixed at one time and then are put into an internal mixer for mixing for 15 minutes at 150 ℃, tablets are prepared by hot pressing, the oxygen index and the mechanical property are tested according to the specification in the national standard GB/T32129-one 2015, and the performance test results of each EVA composite material are as follows:

sample (I)	Oxygen index	Tensile strength (MPa)	Elongation at Break (%)
				EVA-F	51	13.7	231
Comparative sample 1	25	13.0	195
				Comparative sample 2	47	12.8	212
Comparative sample 3	21	12.9	185
				Comparative sample 4	28	13.4	207
Comparative sample 5	26	13.1	190
				Comparative sample 6	27	12.0	210
Comparative sample 7	28	10.8	221
				Comparative sample 8	28.5	12.8	193
Comparative sample 9	30	11.8	201

It can be seen from the comparative sample 2 that, compared with the single use or the compound of two of the oil shale semicoke, the montmorillonite and the attapulgite, the flame retardant property of the EVA composite material can be obviously improved, the flame retardant property of the EVA composite material is also obviously superior to that of the pure modified or unmodified superfine magnesium hydroxide, but the tensile strength is reduced to some extent, and the national standard is still met.

According to EVA-F, after the surface modification treatment of the compound A, the composite flame retardant has better performances than other comparative samples.

As can be seen from the tensile strengths of EVA-F and comparative sample 2 and the tensile strengths of comparative sample 1 and comparative sample 9, the influence of the surface modification of compound A on the composite flame retardant and the ultrafine magnesium oxide shows a significantly different trend.

Example 2

Preparing 98 parts by weight of oil shale semicoke, 1 part by weight of attapulgite, 1 part by weight of montmorillonite and 5 parts by weight of compound A into slurry with the mass concentration of 20-45% by using distilled water, carrying out high-temperature (110 ℃) homogenization and ultrasonic reaction for 2 hours, carrying out centrifugal dewatering, repeatedly washing for 5 times by using a mixed solvent of ethanol and water, preparing the washed paste into 20% slurry, carrying out spray drying at 120 ℃, and controlling the particle size D97 of powder to be not less than 1500 meshes to prepare the compound A surface modified composite flame retardant.

Example 3

70 parts of oil shale semicoke, 29 parts of attapulgite, 1 part of montmorillonite and 3 parts of compound A by weight are prepared into slurry with the mass concentration of 20-45% by using distilled water, the slurry is homogenized at high temperature (80 ℃), ultrasonically reacted for 2 hours under high pressure, centrifuged to remove water, then the slurry is repeatedly washed for 5 times by using a mixed solvent of ethanol and water, the washed paste is prepared into 20% slurry, the slurry is spray-dried at 120 ℃, the particle size D97 of powder is controlled to be not less than 1500 meshes, and the compound A surface modified composite flame retardant is prepared.

Example 4

70 parts of oil shale semicoke, 1 part of attapulgite, 29 parts of montmorillonite and 10 parts of compound A by weight are prepared into slurry with the mass concentration of 20-45% by using distilled water, the slurry is homogenized at high temperature (120 ℃), ultrasonically reacted for 2 hours under high pressure, centrifuged to remove water, then the slurry is repeatedly washed for 5 times by using a mixed solvent of ethanol and water, the washed paste is prepared into 20% slurry, the slurry is spray-dried at 120 ℃, the particle size D97 of powder is controlled to be not less than 1500 meshes, and the compound A surface modified composite flame retardant is prepared.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The oil shale semicoke-based composite flame retardant is characterized in that: the oil shale semicoke-based composite flame retardant mainly comprises oil shale semicoke, attapulgite and montmorillonite which are embedded into each other, wherein the oil shale semicoke, the attapulgite and the montmorillonite are subjected to surface modification treatment by a compound A;

the chemical structural formula of the compound A is as follows:

；

according to the total mass of the oil shale semicoke, the attapulgite and the montmorillonite, the content of the oil shale semicoke is 70-98%, the content of the attapulgite is 1-29%, and the content of the montmorillonite is 1-29%.

2. The oil shale semicoke-based composite flame retardant according to claim 1, characterized in that: according to the total mass of the oil shale semicoke, the attapulgite and the montmorillonite, the content of the oil shale semicoke is 95%, the content of the attapulgite is 2%, and the content of the montmorillonite is 3%.

3. The preparation method of the oil shale semicoke-based composite flame retardant of claim 1 or 2, comprising: mixing and reacting the oil shale semicoke, attapulgite, montmorillonite and the compound A in a water phase to obtain the oil shale semicoke-based composite flame retardant;

ultrasonic treatment is used for reaction.

4. The production method according to claim 3, characterized in that: the addition amount of the compound A is 2-10% of the total mass of the oil shale semicoke, the attapulgite and the montmorillonite.

5. The method of claim 4, wherein: the reaction temperature is 80-120 ℃, and the reaction time is 1-4 hours.

6. The application of the oil shale semicoke-based composite flame retardant of claim 1 or 2 in high polymer materials.

7. The flame-retardant EVA high polymer material comprises EVA serving as a matrix, and is characterized in that: the flame-retardant EVA high polymer material contains 10-30wt% of the oil shale semicoke-based composite flame retardant of claim 1 or 2.

8. The flame-retardant EVA high-molecular material of claim 7, wherein: the particle size D97 of the oil shale semicoke-based composite flame retardant is not less than 1500 meshes.

9. The oil shale semicoke-based composite flame retardant is characterized in that: the oil shale semicoke-based composite flame retardant mainly comprises oil shale semicoke, attapulgite and montmorillonite which are embedded into each other, wherein the mass ratio of the oil shale semicoke to the attapulgite to the montmorillonite is 70-98: 29-1.