阅读说明：本技术 一种芳香族聚酰胺晶须的制备方法 (Preparation method of aromatic polyamide whisker ) 是由 石强 孙秀芳 陈欢欢 刘红 于 2020-06-05 设计创作，主要内容包括：本发明公开一种芳香族聚酰胺晶须的制备方法,其采用芳香族二元胺为第一反应单体,芳香族二元酸或其酰卤化物为第二反应单体,所述第一反应单体和第二反应单体在聚合物溶液中进行缩聚反应,缩聚后原位生成纳米芳香族聚酰胺,再加入稳定剂,然后用所述聚合物溶液的溶剂进行稀释,分离后得到芳香族聚酰胺晶须。本发明制得的芳香族聚酰胺晶须具有力学强度高、耐酸耐碱性的特性,适合广泛用于复合材料领域中。(The invention discloses a preparation method of aromatic polyamide whisker, which adopts aromatic diamine as a first reaction monomer, aromatic diacid or acyl halide thereof as a second reaction monomer, wherein the first reaction monomer and the second reaction monomer are subjected to polycondensation reaction in a polymer solution, nano aromatic polyamide is generated in situ after polycondensation, a stabilizer is added, then the solvent of the polymer solution is used for dilution, and the aromatic polyamide whisker is obtained after separation. The aromatic polyamide whisker prepared by the method has the characteristics of high mechanical strength, acid resistance and alkali resistance, and is suitable for being widely applied to the field of composite materials.)

1. A preparation method of aromatic polyamide whisker is characterized in that: aromatic diamine is used as a first reaction monomer, aromatic diacid or acyl halide thereof is used as a second reaction monomer, the first reaction monomer and the second reaction monomer carry out polycondensation reaction in a polymer solution, nano aromatic polyamide is generated in situ after polycondensation, a stabilizer is added, then a solvent of the polymer solution is used for dilution, and the aromatic polyamide whisker is obtained after separation.

2. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the aromatic diamine is p-phenylenediamine.

3. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the aromatic diacid or the acyl halide thereof comprises one or two of terephthaloyl chloride and terephthalic acid.

4. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the polymer solution comprises one or more than two of polysulfone solution, polyether sulfone solution, polyethylene solution and polyvinylidene fluoride solution.

5. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the solvent of the polymer solution is an organic solvent, and the organic solvent comprises at least one of N, N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone.

6. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the mass percentage concentration of the polymer in the polymer solution is 10-20%.

7. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the mass percentage concentration of the aromatic polyamide generated in the polycondensation reaction is 4 to 18 percent.

8. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: the addition amount of the stabilizer is 1-5% by mass percentage concentration, and the type of the stabilizer comprises at least one of span, tween and coco glucoside.

9. The method of producing the aromatic polyamide whisker according to claim 1, characterized in that: and adding the first reaction monomer into the polymer solution, dissolving completely, and then gradually adding the second reaction monomer under stirring to perform polycondensation reaction.

10. The method of producing the aromatic polyamide whisker according to claim 9, characterized in that: and adding a first reaction monomer, adding a second reaction monomer and then adding a stabilizer into the polymer solution.

Technical Field

The invention relates to a high polymer material technology, in particular to a preparation method of aromatic polyamide whiskers.

Background

Whiskers are micro-nano-sized short fibers grown from high purity single crystals and have mechanical strength equal to that produced by the force between adjacent atoms. The highly oriented structure of the whisker not only enables the whisker to have high strength, high modulus and high elongation, but also has the properties of electricity, light, magnetism, dielectric, electric conduction and super electric conduction.

Whiskers can be classified into two major classes, organic whiskers and inorganic whiskers. At present, the prepared whiskers are generally inorganic materials, such as SiC, potassium titanate, aluminum borate whiskers, aluminum oxide and the like. The metal whiskers are mainly applied to metal matrix composite materials, and the ceramic matrix whiskers and the inorganic salt whiskers can be applied to a plurality of fields such as ceramic composite materials and polymer composite materials. Therefore, when the inorganic material whiskers are used in an organic composite material, an interface treatment is necessary to achieve good combination. However, the existing organic whiskers, such as cellulose whisker, poly (butyl acrylate-styrene) whisker, poly (4-hydroxybenzene methyl ester) whisker (PHB whisker) and the like, have small mechanical strength, acid resistance and alkali resistance, and can not meet the use requirements of composite materials.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of an aromatic polyamide whisker, and the aromatic polyamide whisker prepared by the preparation method has excellent mechanical strength, acid resistance and alkali resistance, and meets the application requirements in composite materials.

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

a preparation method of aromatic polyamide whiskers adopts aromatic diamine as a first reaction monomer, aromatic diacid or acyl halide thereof as a second reaction monomer, the first reaction monomer and the second reaction monomer carry out polycondensation reaction in a polymer solution, aromatic polyamide nano whisker suspension is generated in situ after polycondensation, a stabilizer is added, then a solvent of the polymer solution is used for dilution, and the aromatic polyamide whiskers are obtained after separation.

Further, the aromatic diamine is p-phenylenediamine.

Further, the aromatic diacid or the acyl halide thereof comprises one or two of terephthaloyl chloride and terephthalic acid.

Further, the polymer solution comprises one or more of polysulfone solution, polyethersulfone solution, polyethylene solution and polyvinylidene chloride solution.

Further, the solvent of the polymer solution is an organic solvent, and the organic solvent comprises at least one of N, N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone.

Further, the mass percentage concentration of the polymer in the polymer solution is 15-20%.

Furthermore, the mass percentage concentration of the aromatic polyamide generated in the polycondensation reaction is 4-18%.

Further, 1-5% of stabilizer is added into the system according to the mass percentage concentration, the main purpose is to stabilize the aromatic polyamide whisker generated in the system, so that the whisker does not aggregate or precipitate further, and the stabilizer comprises at least one of span, tween and coco glucoside.

Further, the first reaction monomer is added into the polymer solution, the second reaction monomer is gradually added under the stirring condition after the first reaction monomer is completely dissolved to carry out polycondensation reaction, and then the stabilizer is added.

Compared with the prior art, the invention has the beneficial effects that:

the preparation method of the invention is simple, the prepared poly-p-phenylene terephthamide whisker mainly has rod-shaped straight chain molecule poly-p-phenylene terephthamide parallel aggregation formed micro-nano short fiber, the mechanical strength of the short fiber is equal to the strength generated by adjacent interatomic force, so that the short fiber has the highest theoretical mechanical strength, in addition, as is known, the aromatic polyamide has excellent acid and alkali resistance, and after the aromatic polyamide is used as the nano whisker, the whisker has improved performance, and is more suitable for being used as a reinforcing material and widely applied to the field of composite materials.

Drawings

FIG. 1 is a schematic flow diagram of a method of making one embodiment of the present invention;

FIG. 2 is a transmission electron microscope image of poly-p-phenylene terephthalamide nanowhiskers prepared in example 1 of the present invention;

FIG. 3 is a transmission electron microscope image of poly-p-phenylene terephthalamide nanowhiskers prepared in example 2 of the present invention;

FIG. 4 is a transmission electron microscope image of poly-p-phenylene terephthalamide nanowhiskers prepared in example 3 of the present invention;

FIG. 5 is a transmission electron micrograph of poly (p-phenylene terephthalamide) nanowhiskers prepared according to example 4 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person skilled in the art without making any inventive step are within the scope of the present invention.

A process for preparing aromatic polyamide whisker includes in-situ polycondensation of two reactive monomers in polymer solution to obtain nano-class aromatic polyamide, adding stabilizer, diluting with the solvent of said polymer solution, and separating.

The first reaction monomer of the two reaction monomers is aromatic diamine, and the second reaction monomer is aromatic diacid or acyl halide thereof. The first reaction monomer is p-phenylenediamine. The second reaction monomer is terephthaloyl chloride or terephthalic acid. The polymer solution is formed by dissolving a polymer in an organic solvent.

The polymer can be one or more of polysulfone, polyethersulfone, polyethylene and polyvinylidene chloride. The organic solvent is one or more than two of N, N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone. The polymer is dissolved in the organic solvent to form a polymer solution with the mass percentage concentration of 15-20%.

The stabilizer comprises at least one of span, tween, coco glucoside and lauryl glucoside.

In a further preferred embodiment, a stabilizer is added to the polymer solution, and then two reaction monomers are added to carry out in-situ polycondensation reaction.

Referring to fig. 1, the specific preparation process is as follows:

step 1, preparing a polymer solution: adding a polymer formed by mixing one or more than two of polysulfone, polyether sulfone, polyethylene and polyvinylidene chloride into an organic solvent to prepare a polymer solution with the mass percentage concentration of the polymer of 15-20%. The organic solvent is one or more than two of N, N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone.

Step 2, ice-water bath: and cooling the polymer solution in an ice-water bath manner to reduce the temperature of the system to normal temperature.

Step 3, adding a first reaction monomer: adding a first reaction monomer p-phenylenediamine into the polymer solution at normal temperature, and stirring to obtain a sufficient solution.

And 5, adding a second reaction monomer: and gradually adding the second reaction monomer into the system under the stirring condition to carry out polycondensation reaction. The second reaction monomer is terephthaloyl chloride or terephthalic acid. And adjusting the reaction time and the addition amount of the second reaction monomer to ensure that the mass percentage concentration of the generated aromatic polyamide nanowhiskers in the system is 4-18%. The generated aromatic polyamide nano whisker is poly-p-phenylene terephthamide nano whisker.

Step 6, adding a stabilizer: adding a stabilizer into the system, wherein the stabilizer can be one or a mixture of more than two of span, tween, coco glucoside and lauryl glucoside, and the mass percentage concentration of the stabilizer in the system is controlled to be 1-5%.

And 7, diluting: the organic solution was added to the system.

And 8, separation: filtering or suction filtering to obtain the aromatic polyamide whisker.

And 9, drying. And drying the separated aromatic polyamide whisker to obtain the finished aromatic polyamide whisker product.