阅读说明：本技术 一种全生物基阻燃剂、阻燃pla复合材料及其制备方法 (All-bio-based flame retardant, flame-retardant P L A composite material and preparation method thereof ) 是由 陈思 王旭 吴飞洋 俞陈诚 马猛 施燕琴 何荟文 于 2020-04-13 设计创作，主要内容包括：本发明涉及阻燃剂的设计合成技术领域,为解决传统PLA用阻燃剂存在的阻燃效率低、添加量大、不环保的问题,提供了一种全生物基阻燃剂、阻燃PLA复合材料及其制备方法,所述全生物基阻燃剂,具有以下的结构通式：<Image he="382" wi="700" file="DDA0002448378950000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>式中,A<Sup>+</Sup>为氨基质子化后的生物质含硫氨基酸,其中n＝1～12。本发明的全生物基阻燃剂所使用的原料为生物来源的植酸和含硫氨基酸,即合成的阻燃剂为全生物基阻燃剂,这种全生物基阻燃剂来源绿色,符合现在可持续发展的主题,不仅可以减缓石油短缺危机,还能保护地球环境。(The invention relates to the technical field of design and synthesis of flame retardants, and provides a full-biology-based flame retardant, a flame-retardant P L A composite material and a preparation method thereof, aiming at solving the problems of low flame-retardant efficiency, large addition amount and environmental pollution existing in the traditional flame retardant for P L A, wherein the full-biology-based flame retardant has the following structural general formula: in the formula, A + The biomass contains amino acid with protonated amino, wherein n is 1-12. The invention is a whole plantThe raw materials used by the biomass-based flame retardant are phytic acid and sulfur-containing amino acid which are biologically derived, namely the synthesized flame retardant is a full-biomass-based flame retardant, the source of the full-biomass-based flame retardant is green, the full-biomass-based flame retardant accords with the theme of sustainable development at present, the petroleum shortage crisis can be relieved, and the global environment can be protected.)

1. An all-bio based flame retardant, characterized by the following general structural formula:

in the formula, A⁺Is a biomass sulfur-containing amino acid after amino protonation, wherein n ═1～12。

2. The all-bio based flame retardant of claim 1, wherein said biomass sulfur containing amino acid is selected from one or more of methionine, cystine, cysteine and taurine.

3. A process for the preparation of a flame retardant all bio-based according to claim 1 or 2, comprising the steps of:

(1) dissolving phytic acid in distilled water, and adjusting the pH value to obtain a phytic acid aqueous solution;

(2) dissolving biomass sulfur-containing amino acid in distilled water to obtain a biomass sulfur-containing amino acid aqueous solution;

(3) adding biomass sulfur-containing amino acid aqueous solution into phytic acid aqueous solution, and reacting for 4-7 h at 40-70 ℃;

(4) after the reaction is finished, cooling the reaction product, adding an organic solvent, and separating out and drying through recrystallization to obtain the all-bio-based flame retardant.

4. The preparation method of the all-bio-based flame retardant according to claim 3, wherein the molar ratio of the phytic acid to the biomass sulfur-containing amino acid is 1 (0.5-12).

5. The preparation method of the all-bio-based flame retardant according to claim 3, wherein in the step (1), the mass ratio of the distilled water to the phytic acid is (3-10): 1.

6. the preparation method of the all-bio-based flame retardant according to claim 3, wherein in the step (1), the pH of the phytic acid aqueous solution is 3-5.

7. The preparation method of the all-bio-based flame retardant according to claim 3, wherein in the step (2), the mass ratio of the distilled water to the biomass sulfur-containing amino acid is (4-6): 1.

8. the method for preparing the all-bio based flame retardant according to claim 3, wherein in the step (4), the organic solvent is methanol, ethanol or acetonitrile; the adding amount of the organic solvent is 2-4 times of the total amount of the distilled water in the steps (1) and (2).

9. The flame-retardant P L A composite material containing the all-bio-based flame retardant of claim 1 or 2, wherein the flame-retardant P L A composite material comprises, by mass, 0.5-5% of the all-bio-based flame retardant and 95-99.5% of P L A.

10. The preparation method of the flame-retardant P L A composite material as claimed in claim 9, wherein the flame-retardant P L A composite material is obtained by melt-blending the full-bio-based flame retardant and P L A at the above ratio, and processing at 160-190 ℃ for 8-10 min.

Technical Field

The invention relates to the technical field of design and synthesis of flame retardants, and particularly relates to a full-bio-based flame retardant, a flame retardant P L A composite material and a preparation method thereof.

Background

The polylactic acid (P L A), also known as polylactide, can be prepared by lactide ring-opening polymerization, and can also be prepared from biomass resources such as carbohydrates extracted from plants such as wheat, corn and cassava and the like through the processes of hydrolysis, fermentation, purification and the like.P L A not only has transparency, but also has good biocompatibility, mechanical property, biodegradability and processability, and has full application potential, however, P L A is highly flammable, which greatly limits the practical application of P L A in industries with high flame retardant requirements, and therefore, the polylactic acid is very important for the flame retardant modification of polylactic acid.

The flame retardant modification of the P L A mainly focuses on the flame retardant and the melting mechanical blending of the flame retardant to prepare the flame retardant P L A, and common flame retardants are halogen flame retardants, inorganic flame retardants and intumescent flame retardants.

In conclusion, the existing flame retardant for P L A still has the serious problems of low flame retardant efficiency and large addition requirement, and in addition, most of the raw materials of the flame retardant are derived from non-renewable petroleum and the preparation process is complex, namely, non-renewable components are introduced during the preparation of the P L A composite material, so that the environmental-friendly green development of P L A is seriously influenced.

In recent years, researchers have attempted to prepare green and environmentally friendly flame retardants from biomass materials. The phytic acid is used as a biomass containing phosphorus and has a huge flame retardant potential. Chinese patent literature discloses 'a phytic acid flame-retardant wood and a preparation method thereof', and application publication number is CN110524657A, the phytic acid is used for treating wood, so that the heat insulation performance and the flame-retardant performance of the wood are improved, but a metal zinc compound is introduced into a phytic acid flame retardant, so that the flame-retardant efficiency is improved, but the development of a green environment-friendly flame retardant is not facilitated.

Chinese patent literature discloses a preparation method of a microcapsule coated phytate epoxy resin flame retardant, and application publication No. CN110643071A, the preparation method effectively improves the flame retardant property of epoxy resin by coating phytate through a microcapsule technology, but magnesium chloride and aluminum chloride are introduced in the process of coating phytate by microcapsules, and the development of a real environment-friendly flame retardant is also not facilitated. The research on the all-bio-based flame retardant has practical significance.

Disclosure of Invention

The invention provides a full-biology-based flame retardant for P L A, which is efficient, environment-friendly and small in addition amount, and aims to solve the problems of low flame retardant efficiency, large addition amount and environmental pollution of the traditional flame retardant for P L A.

The invention also provides a preparation method of the all-bio-based flame retardant, which is simple, convenient and safe in the preparation process, does not use toxic and harmful organic reagents, is mild in reaction conditions, does not need complex environments such as high temperature and high pressure, and can realize large-scale industrial production.

The invention also provides a flame-retardant P L A composite material containing the all-bio-based flame retardant, which has excellent flame-retardant effect and mechanical property under the condition of low addition of the flame retardant, and is environment-friendly and degradable.

The invention also provides a preparation method of the flame-retardant P L A composite material containing the all-bio-based flame retardant, which is simple to operate, has no special requirements on equipment and is easy to industrialize.

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

an all-bio based flame retardant having the following general structural formula:

in the formula, A⁺The biomass contains amino acid with protonated amino, wherein n is 1-12.

The raw materials used by the all-bio-based flame retardant are phytic acid and sulfur-containing amino acid which are biologically derived, namely the synthesized flame retardant is the all-bio-based flame retardant which is green in source, accords with the theme of sustainable development at present, can slow down the oil shortage crisis and can protect the global environment.

Preferably, the biomass sulfur-containing amino acids are selected from one or more of methionine, cystine, cysteine and taurine.

A preparation method of a full-bio-based flame retardant comprises the following steps:

(1) dissolving phytic acid in distilled water, and adjusting the pH value to obtain a phytic acid aqueous solution;

(2) dissolving biomass sulfur-containing amino acid in distilled water to obtain a biomass sulfur-containing amino acid aqueous solution;

(3) adding biomass sulfur-containing amino acid aqueous solution into phytic acid aqueous solution, and reacting for 4-7 h at 40-70 ℃; in the step, the reaction mechanism is that raw materials with opposite electric properties undergo an ion complexing reaction to prepare the flame retardant; too low a reaction temperature leads to too slow a reaction rate, and too high a reaction temperature leads to a reduction in yield;

(4) after the reaction is finished, cooling the reaction product, adding an organic solvent, and separating out and drying through recrystallization to obtain the all-bio-based flame retardant.

The preparation process of the all-bio-based flame retardant is simple, convenient and safe, does not use toxic and harmful organic reagents, has mild reaction conditions, does not need complex environments such as high temperature and high pressure, and can realize large-scale industrial production.

Preferably, the molar ratio of the phytic acid to the biomass sulfur-containing amino acid is 1 (0.5-12).

Preferably, in the step (1), the mass ratio of the distilled water to the phytic acid is (3-10): 1.

preferably, in the step (1), the pH of the phytic acid aqueous solution is 3-5. The pH of the aqueous phytic acid solution is controlled within the above range based on the protection of sulfur-containing amino acids.

Preferably, in the step (2), the mass ratio of the distilled water to the biomass sulfur-containing amino acid is (4-6): 1.

preferably, in the step (4), the organic solvent is methanol, ethanol or acetonitrile; ethanol is more preferred. The yield of the organic solvent product is high.

Preferably, in the step (4), the amount of the organic solvent added is 2-4 times of the total amount of the distilled water in the steps (1) and (2). Too low addition of the organic solvent results in residual unreacted raw materials, and too much results in increase of production cost.

The flame-retardant P L A composite material containing the all-bio-based flame retardant comprises the following components, by mass, 0.5-5% of the all-bio-based flame retardant and 95-99.5% of P L A.

The flame-retardant P L A composite material disclosed by the invention is excellent in effect, when the addition amount of a full-bio-based flame retardant is only 0.5 wt%, the L OI is 27.0 and passes FV-0 level (3mm) in a vertical combustion test, the flame-retardant P L A composite material has an excellent flame-retardant effect, and in addition, because the addition amount of the flame retardant is low, the cost is greatly reduced, and the loss of the mechanical property of the material caused by the large addition amount of the flame retardant is also avoided.

According to the proportion, the full-bio-based flame retardant and the P L A are melted and blended, and the mixture is processed at 160-190 ℃ for 8-10 min to obtain the flame-retardant P L A composite material.

Therefore, the invention has the following beneficial effects:

(1) the all-bio-based flame retardant disclosed by the invention uses the phytic acid and the sulfur-containing amino acid which are biologically derived as raw materials, namely the synthesized flame retardant is the all-bio-based flame retardant which is green in source, accords with the theme of sustainable development at present, can slow down the oil shortage crisis and can protect the global environment;

(2) the preparation process of the all-bio-based flame retardant is simple, convenient and safe, does not use toxic and harmful organic reagents, has mild reaction conditions, does not need complex environments such as high temperature and high pressure, and can realize large-scale industrial production;

(3) the flame-retardant P L A composite material prepared by the full-bio-based flame retardant has excellent effect, when the addition amount of the flame retardant is only 0.5 wt%, the L OI is 27.0 and passes FV-0 level (3mm) in a vertical combustion test, and the flame-retardant P L A composite material has excellent flame-retardant effect.

Drawings

FIG. 1 is an IR comparison spectrum of the all-bio based flame retardant (a) prepared in example 1 with phytic acid (b) and taurine (c).

Detailed Description

The technical solution of the present invention is further specifically described below by using specific embodiments and with reference to the accompanying drawings.

In the present invention, all the equipment and materials are commercially available or commonly used in the art, and the methods in the following examples are conventional in the art unless otherwise specified.

In the following examples and comparative examples of the invention, the flame retardant performance is tested according to GB/T2408-2008 and GB/T2406.2-2009, and the tensile strength is tested according to GB/T1040.1-2006.