TWI808445B - Preparation method of biomass flame retardant, flame retardant composite material - Google Patents

Abstract

A biomass flame retardant, comprising: bagasse powder with a plurality of pores, and ammonium dihydrogen phosphate adsorbed in the pores. The invention also provides a preparation method of a biomass flame retardant and a flame retardant composite material. The preparation method of the biomass flame retardant comprises: heat-treating a mixture comprising bagasse powder, phosphoric acid, ammonia water and water, so that the phosphoric acid and ammonia water in the mixture are converted into ammonium dihydrogen phosphate to form a heated mixture; and the heated mixture is subjected to a hydrothermal reaction. The flame retardant composite material comprises: epoxy resin, hardener, and the biomass flame retardant dispersed in the epoxy resin, wherein, based on the total amount of the flame retardant composite material being 100wt%, the content of the biomass flame retardant ranges from 20wt% to 30wt%.

Description

Preparation method of biomass flame retardant, flame retardant composite material

The invention relates to a flame retardant, a preparation method of the flame retardant and a composite material, in particular to a biomass flame retardant, a preparation method of the biomass flame retardant, and a flame retardant composite material containing the biomass flame retardant.

Chinese Patent Announcement No. 105482484B discloses a method for preparing a flame-retardant wood-plastic composite material. In this method, ammonia water is added to a mixture containing plant fibers (such as wood flour, bagasse, rice bran, bamboo powder, sawdust or sisal), aluminum sulfate and magnesium sulfate, and then the steps of standing, stirring and drying are performed to obtain flame-retardant modified plant fibers comprising aluminum hydroxide, magnesium hydroxide and ammonium sulfate. Next, 10 to 250 parts of the flame-retardant modified plant fiber, 90 to 120 parts of plastic (such as polypropylene, polyethylene, polylactic acid, etc.) and 1 to 10 parts of a compatibilizer are melt-blended and formed to obtain a flame-retardant wood-plastic composite material.

Although these flame-retardant wood-plastic composite materials have flame retardancy, when the content of the flame-retardant modified plant fibers in the flame-retardant wood-plastic composite materials reaches 48wt%, the limiting oxygen index of the flame-retardant wood-plastic composite materials is 24.1%. It can be seen that the Such flame-retardant wood-plastic composite materials need a higher content of flame-retardant modified plant fibers to achieve non-combustible and flame-retardant properties. Therefore, this patent case has the problem of high cost due to the high amount of flame-retardant modified plant fibers. In addition, under the design of a predetermined amount of flame-retardant wood-plastic composite material, the amount of high-flame-retardant modified plant fiber will inevitably lead to a reduction in the amount of plastic used, which will affect the basic properties required by the flame-retardant wood-plastic composite material, limiting the application of flame-retardant wood-plastic composite material.

Therefore, the first purpose of the present invention is to provide a biomass flame retardant with good flame retardancy.

Therefore, the biomass flame retardant of the present invention includes bagasse powder and ammonium dihydrogen phosphate. The bagasse powder includes a plurality of pores. The ammonium dihydrogen phosphate is adsorbed in the pores.

The second purpose of the present invention is to provide a flame-retardant composite material with good flame retardancy.

The flame retardant composite material of the present invention includes: epoxy resin, hardener, and the above-mentioned biomass flame retardant. The biomass flame retardant is dispersed in the epoxy resin, wherein, based on the total amount of the flame retardant composite material being 100wt%, the content of the biomass flame retardant ranges from 20wt% to 30wt%.

The third object of the present invention is to provide a kind of Preparation method of biomass flame retardant.

The preparation method of the biomass flame retardant of the present invention comprises: heating a mixture comprising bagasse powder, phosphoric acid, ammonia water and water, so that the phosphoric acid and ammonia water in the mixture are converted into ammonium dihydrogen phosphate to form a heated mixture; and subjecting the heated mixture to a hydrothermal reaction.

The effect of the present invention is that: through the bagasse powder and the ammonium dihydrogen phosphate, the biomass flame retardant of the present invention has excellent flame retardancy. Therefore, the biomass flame retardant of the present invention is applied to epoxy resin, which can improve the flame retardancy of epoxy resin.

The present invention will be described in detail below.

[Biomass flame retardant]

The biomass flame retardant of the present invention comprises bagasse powder and ammonium dihydrogen phosphate. The bagasse powder includes a plurality of pores. The ammonium dihydrogen phosphate is adsorbed in the pores.

Sugarcane is a plant of the Gramineae genus Saccharum , suitable for planting in tropical and subtropical regions. Bagasse refers to the residue left after extracting juice from sugarcane, and is mainly composed of cellulose, hemicellulose, and lignin. The bagasse powder is formed by crushing the bagasse. The pulverization treatment is not particularly limited, as long as the bagasse can be miniaturized. This pulverization process can be performed using a mechanical device such as a pulverizer, for example. In some embodiments of the present invention, the bagasse powder has a particle size of 0.3 mm.

In some embodiments of the present invention, the weight ratio of the ammonium dihydrogen phosphate to the bagasse powder is 1.9:1.

[Flame Retardant Composite Material]

The flame retardant composite material includes: epoxy resin, hardener, and the above-mentioned biomass flame retardant. The biomass flame retardant is dispersed in the epoxy resin, wherein, based on the total amount of the flame retardant composite material being 100wt%, the content of the biomass flame retardant ranges from 20wt% to 30wt%.

The epoxy resin is, for example but not limited to, bisphenol A epoxy resin having epoxy groups at two opposite ends. In some embodiments of the present invention, the epoxy resin is a bisphenol A type epoxy resin having epoxy groups at two opposite ends.

The curing agent is, for example but not limited to, an aliphatic amine curing agent or an aromatic amine curing agent. In some embodiments of the present invention, the hardener is selected from aliphatic amine hardeners, aromatic amine hardeners, or any combination of the above. The aromatic amine hardener is for example but not limited to 4,4-diaminodiphenylmethane and the like. In some embodiments of the present invention, the hardener is 4,4-diaminodiphenylmethane.

The biomass flame retardant is as described above, so it will not be described in detail.

In some embodiments of the present invention, based on the total amount of the flame-retardant composite material being 100wt%, the content of the hardener ranges from 15.1wt% to 17.3wt%.

[Preparation method of biomass flame retardant]

The preparation method of the biomass flame retardant comprises: heat-treating a mixture comprising bagasse powder, phosphoric acid, ammonia water and water, so that the phosphoric acid and ammonia water in the mixture are converted into ammonium dihydrogen phosphate to form a heated mixture; and subjecting the heated mixture to a hydrothermal reaction.

In some embodiments of the present invention, the preparation method of the biomass flame retardant is to sequentially mix the bagasse powder, the water, the phosphoric acid and the ammonia water to form the mixture.

The bagasse powder is as described above, so it will not be repeated.

In some embodiments of the present invention, the molar ratio of the phosphoric acid to the ammonia water is in the range of 1:1.

In some embodiments of the present invention, the temperature of the heat treatment is 60° C., and the time is 1 hour.

The purpose of the hydrothermal reaction is to enable the ammonium dihydrogen phosphate to be tightly adsorbed on the bagasse powder. The hydrothermal reaction is carried out in a closed environment. In some embodiments of the present invention, the temperature of the hydrothermal reaction is 100° C., and the time is 2 hours.

The present invention will be further described with reference to the following examples, but it should be understood that these examples are for illustrative purposes only and should not be construed as limitations on the implementation of the present invention.

Example 1

Bagasse (purchased from Shalu District, Taichung City) was crushed with a pulverizer to form crushed bagasse with a size of 0.3 mm. The crushed bagasse was washed three times with deionized water at 100°C, and then dried in an oven at 100°C to obtain bagasse powder, wherein the bagasse powder had a specific surface area of 2.24m ² /g, a pore volume of 0.003cm ³ /g and an average pore diameter of 74.64Å. 1.82 grams of the bagasse powder, 20 mL of deionized water and 3.3 grams of phosphoric acid aqueous solution (comprising phosphoric acid and water, and the concentration of phosphoric acid is 85 wt%) were mixed and stirred for 10 minutes, then, 3.73 grams of ammonia water (comprising ammonia and water, and the concentration of ammonia was 30 wt%) was added to form a mixture. The mixture was heat-treated at 60° C. for 1 hour to obtain a heated mixture containing ammonium dihydrogen phosphate and crushed bagasse. The heated mixture was placed in an autoclave, and placed in an oven at 100° C. for 2 hours of hydrothermal reaction to obtain a product comprising water and a biomass flame retardant dispersed in water. Then, the product was cooled at room temperature for 2 hours, and then dried in an oven at 100°C for 4 hours to remove the water to obtain the biomass flame retardant, wherein, in the biomass flame retardant, the weight ratio of the ammonium dihydrogen phosphate to the bagasse powder was 1.9:1.

Application example 1

Add 3.19 grams (20wt%) of the biomass flame retardant of Example 1 to 10 grams (62.7wt%) of bisphenol A type epoxy resin (brand: Nan Ya Plastic Industry Co., Ltd.; model: NPEL128; epoxy equivalent: 180 g/equivalent) with epoxy groups at opposite ends of 10 grams (62.7wt%), and stir at 60°C for 2 hours, then add 2.75 grams (17.3wt%) of 4,4-diaminodiphenylmethane and continue Stir until the viscosity rises to 10,000cP to obtain a flame retardant composite.

The flame retardant composite material was poured into a mold and left at room temperature for 24 hours, then placed in an oven and heated from 60°C to 160°C at a rate of 20°C per 2 hours to form a flame retardant cured product.

Application example 2

The preparation method of Application Example 2 is roughly the same as that of Application Example 1, the main difference being: in this Application Example 2, the amount of the biomass flame retardant is 5.46 grams (30wt%), and the amount of the epoxy resin is 10 grams (54.9wt%).

Comparative application example 1

Two opposite ends of 10 grams (78.4WT%) have epoxy-based bisphenol-A-type epoxy resin (label: South Asian Plastic Industry Co., Ltd.; model: NPEL128; Epoxy actuated quantity: 180 grams/equivalent), and 2 hours at 60 ° C. Then, add 2.75 grams (21.6WT%) 4,4-diosamida. Benzine is stirred until the viscosity rises to 10,000cp to obtain flame retardant composite materials.

The flame retardant composite material was poured into a mold and left at room temperature for 24 hours, then placed in an oven and heated from 60°C to 160°C at a rate of 20°C per 2 hours to form a flame retardant cured product.

Comparative Application Example 2 to Comparative Application Example 3

The preparation method of Comparative Application Example 2 to Comparative Application Example 3 is roughly the same as that of Comparative Application Example 1, the main difference being: in this Comparative Application Example 2, 0.67 grams (5wt%) of the biomass flame retardant of Example 1 is added to 10 grams (74.5wt%) of the two opposite ends Bisphenol A type epoxy resin with epoxy group. In the comparative application example 3, 1.42 grams (10wt%) of the biomass flame retardant of Example 1 was added to 10 grams (70.6wt%) of the bisphenol A epoxy resin having epoxy groups at opposite ends.

Comparative application example 4

Be the embodiment 3 of CN105482484B.

Comparative application example 5

Be the embodiment 4 of CN105482484B.

evaluation item

[Thermal Stability Analysis]

For clarity, the following measurement process is described using the flame-retardant cured product of Application Example 1 as a representative, while the remaining application examples and comparative application examples are measured in the same manner.取約5mg至8mg的應用例1的阻燃性固化物作為待測樣品，將5mg至8mg的應用例1的阻燃性固化物置於一台熱重量分析儀(thermogravimetric analyzer，TGA；廠牌：Perkin Elmer；型號：PE Pyris 1)的爐管中，並在流速為120mL/min的氮氣中以20℃/min的升溫速率由30℃升溫至800℃，得到熱重量(thermogravimetry，TG)曲線，並由該熱重量曲線獲得質量損失10%的溫度(簡稱T _d10 )、最大裂解溫度(簡稱T _max )、最大裂解速率(簡稱R _max )、焦炭殘餘率(char Yield)及積分程序裂解溫度(integral procedure decomposition temperature，簡稱IPDT)， 且分析結果呈現於表1中。

[Smoke density analysis]

For clarity, the following measurement process is described using the flame-retardant cured product of Application Example 1 as a representative, while the remaining application examples and comparative application examples are measured in the same manner. According to the ASTM E662 smoke concentration standard test, the flame-retardant cured product in Application Example 1 was cut into a size of 70x70x9mm ³ to obtain a sample to be tested. The sample to be tested was placed in an NBS smoke test chamber (NBS smoke test chamber; brand: FTT; model: NBS SDC), and burned under flameless conditions to obtain a smoke density curve, and the rate of increase in smoke density (abbreviated as R), the maximum smoke density (abbreviated as Dm), and the smoke obscuration index (the smoke obscuration) were obtained from the smoke density curve. index, referred to as SOI). In the grade of the smoke obscuration index, SOI>30 indicates a high risk, an SOI of 10 to 30 indicates a possible risk, and an SOI of 5 or more and less than 10 indicates a low risk.

[Analysis of flame retardant properties]

<UL-94 Combustion Test>

For clarity, the following measurement process is described using the flame-retardant cured product of Application Example 1 as a representative, while the remaining application examples and comparative application examples are measured in the same manner. According to the IEC 60695-11-10 horizontal and vertical combustion fire hazard standard test, the flame-retardant cured product in Application Example 1 was cut into a size of 127x12.7x3mm ³ to obtain a sample to be tested. Fix one end of the sample to be tested with a clamp of a bracket, and make the sample to be tested vertical, then, contact the other end of the sample to be tested with a fire source with a flame height of 20 mm opposite to the one fixed by the clamp for 10 seconds, then remove the flame and record the burning time (t1, unit: second) and the extinguishing time of afterflame or afterflame (t2, unit: second). During the above combustion process, place cotton about 23 cm below the sample to be tested, and observe whether there is dripping and melting, and judge the flame retardancy level of the sample to be tested. Add t1 and t2 to calculate the total burning time, and judge the flame retardancy level of the sample to be tested, and the test results are presented in Table 1. The flame retardancy grades are V-0, V-1 and V-2, among which, V-0 means that the total burning time is within 10 seconds without any dripping phenomenon, V-1 means that the total burning time is within 30 seconds without any dripping phenomenon, V-2 means that the total burning time is within 30 seconds and there is dripping phenomenon, and the grade not up to the standard means that the total burning time exceeds 30 seconds.

<limiting oxygen index (LOI)>

For clarity, the following measurement process is described using the flame-retardant cured product of Application Example 1 as a representative, and the remaining application examples and Comparative Application Example 1 are measured in the same manner. Cut the flame-retardant cured product of Application Example 1 into a size of ^80x10x4mm3 to obtain a sample to be tested. The sample to be tested was placed in a limiting oxygen index measuring instrument (brand: ATLAS Fire Science Products; model: Dynisco LOI), the concentration ratio of nitrogen and oxygen in the instrument was adjusted, and after nitrogen and oxygen were mixed for 30 seconds, the test was started, and the test results are presented in Table 1. In the rating of the limiting oxygen index, LOI≧26% means that it is difficult to ignite and has flame retardancy; LOI of 22% to 25% means that it will automatically extinguish when burning and has self-extinguishing property; and LOI≦21% means that it will burn freely in air and has flammability.

It can be seen from the data in Table 1 that as the addition of biomass flame retardants in these flame-retardant composite materials increases, _Rmax has a significant downward trend, while IPDT has a significant upward trend, which means that the flame-retardant cured products formed by these flame-retardant composite materials have good thermal stability. In addition, as the addition amount of the biomass flame retardant in the flame retardant composite materials increases, the coke residual rate of the flame retardant cured products formed by the flame retardant composite materials is significantly improved. It can be seen that after the flame retardant cured materials are burned, a coke layer will be formed on the surface to prevent the flame retardant cured products from contacting with combustible gases, thereby preventing the flame from continuing to burn the flame retardant cured products, so that the flame retardant cured products have excellent flame retardancy. Furthermore, from the limiting oxygen index of Application Examples 1 and 2 and comparative Application Examples 2 and 3, it can be known that these flame-retardant composite materials have self-extinguishing or flame retardancy, and as the addition amount of biomass flame retardant increases, these flame-retardant composite materials have better flame retardancy. From the results of the UL-94 combustion test, it can be known that when the content of the biomass flame retardant in the flame-retardant composite materials is further 20wt% to 30wt%, the flame-retardant grade of the flame-retardant composite materials can reach V-1, or even V-2, and have more excellent flame retardancy.

In contrast to Comparative Application Examples 4 and 5, in Comparative Application Example 4, the limiting oxygen index of the composite material formed by the flame-retardant modified plant fiber content reaching 48wt% is not better than that of Application Examples 1-2. Similarly, in Comparative Application Example 5, the limiting oxygen index of the composite material formed by the flame-retardant modified plant fiber content of 28wt% is not better than Application Examples 1-2. .

In summary, through the bagasse powder and the ammonium dihydrogen phosphate, the biomass flame retardant of the present invention has excellent flame retardancy. Therefore, the application of the biomass flame retardant of the present invention In the epoxy resin, the flame retardancy of the epoxy resin can be improved, so the purpose of the present invention can be achieved indeed.

But the above are only embodiments of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the patent of the present invention.

Claims (7)

A flame retardant composite material, comprising: epoxy resin; a hardener; and a biomass flame retardant, dispersed in the epoxy resin, and including bagasse powder with a plurality of pores and ammonium dihydrogen phosphate bonded to the bagasse powder and located in the pores; wherein, based on the total amount of the flame retardant composite material being 100wt%, the content of the biomass flame retardant ranges from 20wt% to 30wt%. The flame-retardant composite material according to claim 1, wherein, based on the total amount of the flame-retardant composite material being 100wt%, the content of the hardener is 15.1wt% to 17.3wt%. The flame-retardant composite material according to claim 1, wherein the hardener is 4,4-diaminodiphenylmethane. A preparation method of a biomass flame retardant, comprising: mixing bagasse powder, phosphoric acid and water so that the phosphoric acid is bonded to the bagasse powder, then adding ammonia water to form a mixture, and performing heat treatment so that the phosphoric acid bonded to the bagasse powder reacts with ammonia water to convert into ammonium dihydrogen phosphate to form a heated mixture; and making the heated mixture undergo a hydrothermal reaction. The preparation method of the biomass flame retardant according to claim 4, wherein the molar ratio of the phosphoric acid to the ammonia water is 1:1. The preparation method of a biomass flame retardant as claimed in Claim 4, wherein the temperature of the heat treatment is 60° C., and the time is 1 hour. The method for preparing a biomass flame retardant as claimed in claim 4, wherein the temperature of the hydrothermal reaction is 100° C., and the time is 2 hours.