Biodegradable composite material with a bio-based flame retardant

Abstract

The present invention provides a biodegradable composite material containing a halogen-free, non-toxic intumescent bio-based flame retardant. Natural ingredients such as tea polyphenols and plant fibers are used to replace traditional petroleum-based carbon sources and are incorporated into bio-based polybutylene succinate (PBS). Furthermore, through the condensation reaction of fibers and tetraethoxysilane (TEOS), the material functions as a carbon source for the flame retardant system; ammonium polyphosphate, a halogen-free flame retardant, serves as the acid source; and melamine serves as the gas source—together forming a ternary intumescent flame retardant system. Additionally, zinc oxide is introduced as a catalyst to enable synergistic effects and promote compatibility through coupling reactions, resulting in a novel synergistic bio-based flame retardant. TEOS and ZnO further induce a networked cross-linked structure within the material, thereby enhancing the flame retardancy and thermal stability of the composite. As a result, a flame-retardant bio-based PBS composite material aligned with the principles of circular economy is successfully developed.

Description

[Technical Field]

[0001] A biodegradable composite material, particularly a biodegradable composite material with a biomass flame retardant. [Previous Technology]

[0002] With the global focus on net-zero carbon emissions, economic cycles, and sustainable environmental protection in recent years, sustainable materials have become a current trend, prompting the rapid development of biopolymers. Polybutylene succinate (PBS) is one of the few materials that can be produced from renewable resources and can be decomposed into water and carbon dioxide by various microorganisms or plant and animal enzymes in the environment. Due to its heat resistance and easy processing properties, it has received much attention.

[0003] It has shown excellent potential in the fields of automotive components and electronic products. However, applications in the automotive and electronic fields often require high flame retardancy. Pure PBS has a limiting oxygen index (LOI) between 21 and 24. Due to the characteristics of its chemical structure, the material is prone to absorbing water molecules in the air and is not flame retardant, which hinders its application in many industrial fields.

[0004] Although the application of PBS continues to increase, the development of its flame-retardant properties remains insufficient. However, with the continued increase in applications, it is clear that the demand for flame-retardant properties of PBS will be crucial. Therefore, focusing on the development of environmentally friendly flame-retardant PBS materials, and moving towards high flame-retardant efficiency, non-toxicity, and low smoke, is an urgent problem to be solved. [Summary of the Invention]

[0005] To address the current shortcomings in the development of flame-retardant properties of polybutylene succinate (PBS), and to further advance the goal of achieving high flame-retardant efficiency, non-toxicity, and low smoke in PBS, this invention provides a biodegradable composite material containing a bio-based flame retardant, comprising 5-95 wt% polybutylene succinate and 5-95 wt% bio-based flame retardant, wherein: 5-95 wt% polybutylene succinate and 5-95 wt% bio-based flame retardant;

[0006] The biomass flame retardant contains: tea polyphenols; plant fiber; ammonium polyphosphate; melamine or zinc oxide; wherein the ratio of tea polyphenols: plant fiber: ammonium polyphosphate: melamine or zinc oxide is 1:1:3:1.

[0007] The plant fiber is a plant fiber modified with tetraethoxysilane.

[0008] The particle size of the plant fiber is below 30 mesh.

[0009] The moisture content of the plant fiber is less than 5%, or preferably less than 1%.

[0010] Polybutylene succinate and the biomass flame retardant are mixed and blended using a screw mixer to form a biodegradable composite material containing the biomass flame retardant.

[0011] The biodegradable composite material with bio-flame retardant has a UL-94 rating of V2-V0 and produces slight or no dripping when burning for more than 30 seconds.

[0012] As can be seen from the above description, the present invention has the following beneficial effects and advantages:

[0013] 1. This invention successfully developed a halogen-free, non-toxic intumescent flame retardant, utilizing natural components such as tea polyphenols and plant fibers to replace traditional petroleum-based carbon sources, which are added to biomass polybutylene succinate (PBS). Furthermore, the carbon source of the intumescent flame retardant can be obtained through the condensation reaction of fibers and tetraethoxysilane, the acid source can be obtained through the halogen-free flame retardant ammonium polyphosphate, and the gas source can be obtained through melamine, combining the three sources (in a 1:3:1 ratio). Further, zinc oxide (ZnO) is introduced as a catalyst to form a novel synergistic intumescent flame retardant that is compatible with both coupling reactions. Through TEOS and ZnO, a network cross-linked structure is formed inside the material, thereby improving the flame retardancy and thermal stability of PBS, successfully preparing a biomass polybutylene succinate (PBS) flame-retardant composite material with a circular economy.

[0014] 2. By using TEOS to form a network cross-linked structure within the material, the thermal stability and flame-retardant and anti-dripping effects of the composite material are increased. The best flame-retardant effect is achieved when the flame retardant content is increased to 30%, with the limiting oxygen index (LOI) increasing from 22% in pure PBS to 40%, and the vertical burning test (UL-94) achieving a V-0 rating with no dripping. TGA results show that the char residue rate increases from 1.98 wt.% in pure PBS to 11.37 wt.%. This invention improves the flame-retardant properties of the composite material during combustion, enabling a UL-94 V-0 rating. In the preferred embodiment, only 20% of the zinc oxide-containing synergistic intumescent flame retardant needs to be added to PBS to achieve a V-0 rating and an LOI value of 30%, which further enhances the thermal stability of the composite material.

Implementation Method

[0015] The present invention will be described and illustrated in detail below with reference to several preferred embodiments. The accompanying drawings are merely some exemplary representations or embodiments of the present invention. For those skilled in the art, the present invention can be applied to other similar situations based on these drawings without any further effort.

[0016] The terms “system,” “apparatus,” “unit,” and / or “module” used in this invention are to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other words can achieve the same purpose, they may be replaced by other expressions. As shown in this invention, unless the context clearly indicates otherwise, words such as “a,” “an,” “an,” and / or “the” do not specifically refer to the singular and may also include the plural. Generally speaking, the terms “comprising” and “including” only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0017] Flowcharts are used in this invention to illustrate the operations performed by the system according to embodiments of the invention. It should be understood that the preceding or following operations are not necessarily performed precisely in sequence. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0018] <Biodegradable composite materials with bio-flame retardants>

[0019] This invention provides a biodegradable composite material with a bio-based flame retardant, comprising: a uniformly mixed amount of 5-95 wt% polybutylene succinate (PBS); and a bio-based flame retardant comprising: tea polyphenols; plant fiber or tetraethoxysilane (TEOS) modified plant fiber; ammonium polyphosphate (APP); melamine (MEL) or zinc oxide (ZnO); wherein the ratio of tea polyphenols (TR): plant fiber or tetraethoxysilane (TEOS) modified plant fiber: ammonium polyphosphate (APP): melamine (MEL) or zinc oxide (ZnO) is 1:1:3:1 to 1:1:10:1.

[0020] Wherein, the particle size of the plant fiber is less than 30 mesh, and the moisture content is less than 5%, or more preferably less than 1%. Preferably, polybutylene succinate (PBS) and the biomass flame retardant are mixed using a screw mixer to form a biodegradable composite material containing the biomass flame retardant.

[0021] A preferred method for modifying plant fibers with tetraethoxysilane (TEOS) is as follows: First, place tetraethoxysilane in a beaker and increase its solution volume with acetone. Pour plant fibers preheated at 100°C for 2 hours into the beaker containing tetraethoxysilane and acetone and place it on a heated high-speed stirrer. Use the sol-gel method to stir at 600 rpm and 150°C for 20 minutes. The heat generated by the heated high-speed stirrer causes the plant fibers and tetraethoxysilane to undergo a hydrolysis and condensation reaction to form tetraethoxysilane (TEOS) modified plant fibers. Then, use a vacuum filtration method to remove the remaining acetone from the moistened tetraethoxysilane (TEOS) modified plant fibers until they are dry. Finally, place them in an oven to dry for 30 minutes.

[0022] <Validity Test>

[0023] Please refer to Table 1 below, which is a list of the ingredients of several preferred embodiments and comparative examples of the present invention.

[0024] Table 1. Element sample PBS (wt%) The amount of bio-based flame retardant added is the remainder after deducting PBS, and it contains the following components in a ratio of 1:1:3:1. Tea polyphenols Plant fiber or TEOS-modified plant fiber; APP MEL or ZnO Comparative Example 100 none none none none Example 1 95 Tea polyphenols plant fiber APP MEL Example 2 90 Tea polyphenols plant fiber APP MEL Example 3 80 Tea polyphenols plant fiber APP MEL Example 4 75 Tea polyphenols plant fiber APP MEL Example 5 70 Tea polyphenols plant fiber APP MEL Example 6 95 Tea polyphenols TEOS-modified plant fiber APP MEL Example 7 90 Tea polyphenols TEOS-modified plant fiber APP MEL Example 8 80 Tea polyphenols TEOS-modified plant fiber APP MEL Example 9 75 Tea polyphenols TEOS-modified plant fiber APP MEL Example 10 70 Tea polyphenols TEOS-modified plant fiber APP MEL Example 11 95 Tea polyphenols plant fiber APP ZnO Example 12 90 Tea polyphenols plant fiber APP ZnO Example 13 80 Tea polyphenols plant fiber APP ZnO Example 14 75 Tea polyphenols plant fiber APP ZnO Example 15 70 Tea polyphenols plant fiber APP ZnO

[0025] The present invention will now perform thermal property analysis and flame retardant property analysis on the above comparative examples and several preferred embodiments.

[0026] Analysis of thermal properties

[0027] 1. Thermogravimetric Analysis (TGA): The thermogravimetric analysis (TGA) curves in Figure 1, obtained by comparing the comparative examples in Table 1 above with several embodiments of the present invention under a nitrogen atmosphere at a heating rate of 10 °C / min, are shown in Figures 1A and 1B, and summarized in Table 2. The initial pyrolysis temperature (Td5) is the temperature at which the flame-retardant composite material loses 5% of its weight; the char yield (CY) is the percentage of weight remaining after the flame-retardant composite material burns to 800 °C; and Tmax is the temperature at which the composite material reaches its maximum pyrolysis rate. Figure 1A shows the TGA graphs of the flame-retardant composite materials of the comparative example (pure PBS), Example 5 (PBS / TR / APP / MEL 30%), Example 10 (PBS / TEOS-TR / APP / MEL 30%), and Example 15 (PBS / TR / APP / ZnO 30%) under nitrogen atmosphere. The results show that the CY of the comparative example increased from 1.98 wt.% to 14.39 wt.%, 11.37 wt.%, and 14.29 wt.% respectively after the flame retardant content in the several examples of the present invention was increased to 30%. The Td5 of pure PBS was 367°C, which indicates that the comparative example began to decompose at 367°C. After the flame retardant content of the present invention was increased by 30%, the Td5 was 313°C, 313°C, and 324°C respectively, which significantly accelerated the decomposition. The above results indicate that the phosphorus groups contained in APP cause the PBS substrate to decompose and promote coke formation when heated, thereby protecting the substrate and increasing thermal stability and coke residue.

[0028] Table 2. sample T d5 ( o C) Tmax ( o C) CY (wt.%) Comparative Example 367 400 1.98 Example 5 313 341 14.39 Example 10 324 341 11.37 Example 15 324 339 14.29

[0029] 2. The results of the integral procedure decomposition temperature (IPDT) analysis are shown in Figure 2 and Table 3 below. The IPDT value of the comparative pure PBS was calculated to be 388℃ using the initial decomposition temperature Td5, coke residue CY, and thermal stability factors (A*, K*). After adding different amounts of flame retardant according to the present invention, the IPDT value also increased with the increase of the flame retardant content. When the flame retardant was added, the IPDT value was higher than the 388℃ calculated for pure PBS. This is because the IPDT value increases with the increase of P and N elements in the flame retardant in the composite material, thus proving that the thermal stability of the flame-retardant composite material of the present invention is significantly improved.

[0030] Table 3. sample A* K* IPDT value ( o C) Comparative Example 0.488 0.953 388 Example 5 0.507 1.396 575 Example 10 0.497 1.297 526 Example 15 0.517 1.382 580

[0031] 3. Thermogravimetric analysis / infrared spectroscopy (TG-FTIR) is shown in Figure 3. In the figure, a is the FTIR spectrum of the comparative example, b is Example 5, c is Example 10, and d is Example 15, measured by thermogravimetric analysis at the maximum pyrolysis rate. The gaseous products volatilized by the material during thermal pyrolysis can be observed in the spectrum. The main decomposition products of PBS during decomposition are hydrocarbons, carbon dioxide (CO2), methanol, acid anhydrides, and aliphatic ethers. The results show that the main product peaks are located at H2O (3742 cm-1), hydrocarbons (2940 cm-1), CO2 (2360 cm-1 and 670 cm-1), carbonyl compounds (1743 cm-1), aromatic compounds (1510 cm-1), and CH (1380 cm-1). The presence of POC (1048 cm⁻¹) and NH₃ (930 cm⁻¹) after the addition of the flame retardant of this invention is mainly due to the presence of P and N elements in the flame retardant. During high-temperature pyrolysis of the composite material, P free radicals and NH₃ gas are released. These P free radicals can capture H₂, O₂, and OH₃ free radicals generated during combustion, further disrupting the chain reaction produced during combustion and forming polyphosphates that coat the surface of the composite material, creating a barrier. Furthermore, the generation of NH₃ and the increase in CO₂ further dilute the concentration of flammable gases in the air. All of this demonstrates that the various embodiments of the added flame retardant can improve the flame-retardant effect of the composite material in both the condensed and gas phases.

[0032] Figure 4 shows the decomposition of gaseous products at different temperatures for (a) Comparative Example, (b) Example 5, (c) Example 10, and (d) Example 15. First, as the temperature rises to 300 °C, there is no obvious decomposition in the Comparative Example and several embodiments of the present invention. However, it can be observed that CO2 in the Examples begins to increase significantly. When the temperature reaches 400 °C, decomposition begins to occur. It is found that after the introduction of the flame retardant in the Examples, the peak value of the decomposition wave is significantly larger than that in the Comparative Example. This is mainly because the P element contained in the flame retardant in the Examples promotes the early decomposition of the substrate when burned and begins to release P, thereby disrupting the chain reaction generated by H, O, and OH. The N element contained in the flame retardant in the Examples will further decompose into non-flammable gases NH3 and CO2. With the increase of non-flammable gases, the flammable gases in the air are diluted, thereby achieving self-extinguishing effect. As explained above, the embodiments of the present invention do indeed produce a gas-phase flame-retardant effect.

[0033] Analysis of the flame-retardant properties

[0034] 1. Horizontal and vertical burning tests (UL-94) and limiting oxygen index (LOI), please refer to Figure 5 and Table 4 below. In the comparative example of the UL-94 test, the burning time exceeded 30 seconds and was accompanied by a fairly serious dripping phenomenon, so the rating could not be determined (Fail). After the addition of flame retardants in each embodiment of the present invention, the ratings can be determined as V2-V0 respectively, with only slight or no dripping phenomenon. As can be seen from the above, the present invention can effectively improve the flame retardant properties of PBS. However, through the catalysis of tea polyphenols, plant fibers (with or without TEOS modification), and ZnO and acid source, the SiO2 generated by TEOS and the Zn3(PO4)2 generated by ZnO have good heat resistance properties and form a network structure inside the flame retardant composite material, thereby improving the quality and strength of the carbon layer during combustion. The tea polyphenols and plant fibers in the flame retardant provide a char layer that forms when the flame-retardant composite material is heated, thus isolating it from flames. The phosphorus (P) element in ammonium polyphosphate (APP) promotes early decomposition of the substrate, further dehydrating it to form a phosphorus char layer that blocks heat transfer, protecting the substrate from further decomposition. It also generates non-flammable gases such as phosphorus (P), NH3, and CO2 in the gas phase, interrupting the chain reaction and diluting the concentration of flammable gases, achieving a flame-retardant effect. In a comparative LOI test, the LOI value was only 22%, classifying it as a highly flammable polymer. However, with the addition of the flame retardant of this invention, even at only 5%, the LOI value reached 23%, exhibiting flame retardancy and self-extinguishing properties. As the addition amount increased, the LOI value rose to 30-40%, classifying it as a flame-retardant polymer. Therefore, it can be seen that the flame retardant added in this invention, after being heated at high temperatures, further promotes the formation of char, preventing the flame-retardant composite material from decomposing and thus protecting the PBS substrate.

[0035] Table 4. sample UL-94 LOI (%) △LOI t1 t2 drip grade Comparative Example BC - Yes, serious. Unable to classify twenty two 0 Example 1 7.0 15.8 slight V2 twenty three 1 Example 2 16.7 2.6 slight V2 twenty four 2 Example 3 10.6 13.2 slight V2 30 8 Example 4 2.8 5.6 none V0 34 12 Example 5 1.0 1.6 none V0 35 13 Example 6 11.8 4.4 slight V2 27 5 Example 7 3.8 5.4 slight V2 27 5 Example 8 1.0 8.6 slight V2 31 9 Example 9 1.0 4.0 none V0 34 12 Example 10 1.0 1.2 none V0 40 18 Example 11 1.4 4.8 slight V2 27 5 Example 12 8.8 1.4 slight V2 27 5 Example 13 1.8 7.2 none V0 30 8 Example 14 1.3 3.0 none V0 36 14 Example 15 1.0 1.6 none V0 37 15

[0036] 2. Cone calorimeter (CCT) tests are shown in Figures 6A and 6B and Table 5, which are curves of heat release rate, total heat release, smoke production rate, total smoke production, and average heat release rate for (a) comparative example, (b) example 5, (c) example 10, and (d) example 15, respectively. Table 5 shows the data measured by the cone calorimeter. Test results showed that the TTI (Time to Ignition) of several embodiments of the present invention was delayed, indicating that water vapor during the heat release process may dilute flammable products and delay ignition time. The maximum heat release rate (pHRR) also decreased, indicating that the present invention helps suppress the heat generated during the combustion of composite materials. The phenomenon of two heat release peaks in the pHRR is due to the cracking under thermal energy, which produces a heat insulation effect and slows down combustion. However, the insufficient protection of the char layer under thermal radiation causes it to crack, resulting in an increase in surface temperature and internal contact with heat energy, thus generating a second heat peak. Nevertheless, the decrease in pHRR still confirms that the flame retardant can effectively reduce the instantaneous heat release, thereby suppressing the heat generated during combustion. The addition of the flame retardant in this invention can effectively suppress the heat generation during the combustion of composite materials, and the formation of an expanded phosphorus char layer through the action of phosphorus and silicon elements achieves the effect of protecting the substrate and slowing down the material's combustion rate, increasing the safety of the material in use.

[0037] Table 5. sample Comparative Example Example 5 Example 10 Example 15 Ignition time TTI(s) 63 64 69 65 Maximum heat release rate pHRR (kw / m 2 ) 438.2 209.6, 256.1 368.9, 435.2 375.6 Average heat release rate av-HRR(kw / m 2 ) 105.5 85.9 85.5 94.7 Total heat release THR (MJ / m 2 ) 25.3 21.8 20.7 24.2 Average effective heat of combustion av-EHC (MJ / Kg) 62.5 18.8 19.2 19.4 Smoke release rate pSPR(m 2 / s 2 ) 0.036 0.028 0.051 0.040 Total smoke emissions TSP(m 2 ) 1.79 1.74 2.62 2.17 Heat release rate MARHE(kw / m 2 ) 182.9 117.3 143.5 147.5 quality Mass (wt.%) 25.4 33.0 32.0 18.7 Fire resistance index FPI (m 2 s / kw) 0.144 0.211 0.159 0.141 Flame retardancy index FRI 1 1.7 1.35 1.03

[0038] Analysis of Coke Analysis

[0039] 1. Electron spectrometry (XPS) analysis revealed changes in the chemical bonds of the flame-retardant composite materials of Examples 5, 10, and 15 after combustion at room temperature and at 600°C for 30 minutes, confirming the flame-retardant mechanism resulting from the introduction of flame retardants containing phosphorus, nitrogen, silicon, and zinc. As shown in Figure 7, the C1s spectra of the flame-retardant composite materials of Examples 5, 10, and 15 after combustion at room temperature and at high temperature were observed. The results showed that after calcination at 600°C for 30 minutes, the C / CH and O-Si-C bonds decreased due to high-temperature oxidation, while the C=C bonds increased and C-Si bonds appeared. This is due to the graphitization structure formed after high-temperature combustion, achieving the flame-retardant effect.

[0040] As can be seen in Figure 8, after deep oxidation of the present invention through high temperature, P2O5, P2O74- compounds are generated, and PO-Zn is increased. This shows that the phosphate substances and inorganic phosphorus compounds formed by the thermal decomposition of APP, as well as PO-Zn, are increased. It can be inferred that the phosphate substances formed by the thermal decomposition of APP react with Zn atoms to form the phosphate substances. All of these are obtained by high-temperature calcination of the bonds in APP and are then covered on the surface of the substrate to form a coke protective layer.

[0041] Figure 9 shows the N1s spectra of the flame-retardant composite materials of Examples 5, 10, and 15 at room temperature and after high-temperature combustion. Through the formation of pyridine, pyrrole, NOx, CN, NH and other bonds after high-temperature oxidation, the barrier carbon layer formed after combustion can have better thermal stability.

[0042] Figure 10 shows the Si 2p and Zn 2p 3 spectra of Examples 5, 10, and 15 at room temperature and after high-temperature combustion. This indicates that after combustion, the substrate forms a protective layer of inorganic silica glass and zinc phosphate on its surface, which can effectively isolate the transfer of heat and flammable gases, thereby improving thermal stability and flame retardancy.

[0043] 2. Raman spectroscopy analysis, as shown in Figure 11 and Table 6, shows the products obtained after calcination in a high-temperature furnace at 600°C for 5 minutes in Examples 5, 10, and 15. The coke was analyzed, and the changes in the Raman D-band (Disorder band) and G-band (Graphilic band) were observed. This invention, through the introduction of flame retardants, can still effectively promote the formation of an intumescent carbonized layer in the composite material, thereby improving the strength and graphitization degree of the carbonized layer, thus achieving the blocking and suppression of the transfer of heat and flammable gases.

[0044] Table 6. sample Graphite Carbon G-Band Disordered carbon D-Band I D / I G 1580 cm-1 1350 cm-1 Example 1 137109 39327 3.49 Example 5 143692 44563 3.22 Example 6 203279 43523 4.67 Example 10 167698 43216 3.88 Example 11 330417 81284 4.06 Example 15 698719 190500 3.56

[0045] Analysis of Mechanical Performance

[0046] Please refer to Table 7 below. Use a universal testing machine to observe the tensile strength and elongation at break of the composite materials after adding flame retardants in the comparative examples and embodiments of the present invention. The results show that after TEOS is modified, its interface forms good chemical bonds and generates a Si-O-Si network structure through crosslinking reaction, thereby improving the compatibility between the flame-retardant material and PBS.

[0047] Table 7. Comparative Example Tensile test Tensile strength Elongation at break Comparative Example 26.7 + / - 1.2 115 + / - 5 Example 5 16.4 + / - 0.4 49 + / - 1 Example 10 16.9 + / - 0.4 54 + / - 5 Example 15 16.1 + / - 0.1 41 + / - 5

[0048] In a high-temperature environment, the flame-retardant mechanism of this invention allows APP in the flame retardant to decompose into compounds such as polyphosphate or pyrophosphate. Through the catalysis of phosphoric acid substances, the PBS substrate dehydrates, releasing H₂O and thus enhancing the carbonization effect. Silicon elements in TEOS migrate to the substrate surface after thermal combustion, forming a layer of inorganic matter (SiO₂), thereby achieving physical shielding. The introduction of ZnO accelerates the dehydration reaction between APP and PBS, further decomposing into compounds such as polyphosphate, pyrophosphate, or zinc phosphate. Under the catalysis of these phosphoric acid substances, these react with phosphates formed by the thermal decomposition of APP and Zn atoms to form PO-Zn bonds. These bonds further form Zn-OC bonds with PBS, tea polyphenols, and fiber carbon atoms. The phosphate groups from the APP decomposition bond with Zn to form Zn₃(PO₄)₂. MEL further decomposes to release non-flammable NH₃. The 3-carbon layer dilutes the concentration of oxygen and flammable gases, generating a large amount of phosphorus-containing expanded carbon. This expanded carbon layer prevents the volatilization and propagation of flammable gases and oxygen, as well as the transfer of heat, thus preventing further decomposition of the material beneath the char layer and continued combustion. Furthermore, the phosphate compounds further decompose, forming PO₂ and PO• free radicals, which capture H•, O•, OH•, and other free radicals produced during combustion, thereby interrupting the chain reaction and achieving flame retardancy.

[0049] Flowcharts are used in this invention to illustrate the operations performed by the system according to embodiments of the invention. It should be understood that the preceding or following operations are not necessarily performed precisely in sequence. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0050] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples by the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical fields and parameters used to confirm their breadth of range in some embodiments of the invention are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0051] Finally, it should be understood that the embodiments described in this invention are merely illustrative of the principles of the invention. Other modifications may also fall within the scope of this invention. Therefore, alternative configurations of the embodiments of this invention are considered as examples and not limitations, and are regarded as consistent with the teachings of this invention. Accordingly, the embodiments of this invention are not limited to those explicitly described and illustrated herein. [Simplified Explanation of the Diagram]

[0052] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention and are not intended to limit the technical scope of the present invention. Unless obvious from the context or otherwise stated, the same reference numerals in the figures represent the same structures or operations. Wherein: Figures 1A and 1B are thermogravimetric analysis (TGA) curves of comparative examples and several preferred embodiments of the present invention. Figure 2 is the integral program pyrolysis temperature analysis (IPDT) analysis of comparative examples and several preferred embodiments of the present invention. Figure 3 is the thermogravimetric analysis / infrared spectroscopy analysis of comparative examples and several preferred embodiments of the present invention. Figure 4 is the pyrolysis of gaseous products at different temperatures of comparative examples and several preferred embodiments of the present invention. Figure 5 is the horizontal and vertical combustion test (UL-94) and limiting oxygen index (LOI) of comparative examples and several preferred embodiments of the present invention. Figures 6A and 6B are curves of heat release rate, total heat release, smoke production rate, total smoke production, and average heat release rate of comparative examples and several preferred embodiments of the present invention, respectively. Figures 7-10 show comparative examples and the electron spectrometer (XPS) analysis of several preferred embodiments of the present invention. Figure 11 shows comparative examples and the Raman spectrometer analysis of several preferred embodiments of the present invention.

Claims

1. A biodegradable composite material containing a biomass flame retardant, comprising 5-95 wt% uniformly mixed polybutylene succinate; and 5-95 wt% biomass flame retardant, wherein: the biomass flame retardant comprises: tea polyphenols; plant fibers with a particle size of less than 30 mesh and a moisture content of less than 5%; ammonium polyphosphate; melamine or zinc oxide; wherein, The weight ratio of tea polyphenols: plant fiber: ammonium polyphosphate: melamine or zinc oxide is 1:1:3:

1.

2. The biodegradable composite material with bio-flame retardant as described in claim 1, wherein: The plant fiber is a plant fiber modified with tetraethoxysilane.

3. A biodegradable composite material with a bio-flame retardant as described in claim 1 or 2, wherein: The moisture content of this plant fiber is less than 1%.

4. A biodegradable composite material with a bio-flame retardant as described in claim 1 or 2, wherein: Polybutylene succinate and the biomass flame retardant are mixed using a screw mixer to form a biodegradable composite material containing the biomass flame retardant.

5. A biodegradable composite material with a bio-based flame retardant as described in claim 1 or 2, wherein: The biodegradable composite material with bio-flame retardant has a UL-94 rating of V2-V0 and produces slight or no dripping when burned for more than 30 seconds.

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