阅读说明：本技术 一种含改性poss纳米粒子的水性pan原丝油剂及其制备方法 (Water-based PAN precursor oiling agent containing modified POSS nanoparticles and preparation method thereof ) 是由 田磊 杭传伟 彭飞 徐牛牛 殷伟涛 崔峙 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种含改性POSS纳米粒子的水性PAN原丝油剂,包括改性硅油、改性POSS纳米粒子、表面活性剂、润滑剂、消泡剂、抗静电剂和去离子水,其中改性硅油的质量分数为15%～40%,改性POSS纳米粒子的质量分数为0.1%～2.0%,表面活性剂的质量分数为3%～15%,润滑剂的质量分数为0.1%～2.0%,消泡剂的质量分数为0.01%～0.5%,抗静电剂的质量分数为0.01%～0.5%,去离子水的质量分数为40%～80%。在原丝生产过程中,加入含改性POSS纳米粒子的水性PAN原丝油剂,能够大幅度提升原丝的性能,使其具有更好的集束性,以及更好的原丝强度和碳纤维强度。(The invention discloses a water-based PAN precursor oil agent containing modified POSS nano particles, which comprises 15-40% of modified silicone oil, 0.1-2.0% of modified POSS nano particles, 3-15% of surfactant, 0.1-2.0% of lubricant, 0.01-0.5% of defoaming agent, 0.01-0.5% of antistatic agent and 40-80% of deionized water. In the protofilament production process, the aqueous PAN protofilament oiling agent containing the modified POSS nano particles is added, so that the performance of the protofilament can be greatly improved, and the protofilament has better bundling property, better protofilament strength and better carbon fiber strength.)

1. An aqueous PAN precursor oil agent containing modified POSS nano particles is characterized in that: the modified silicone oil-water composite material comprises 15-40% of modified silicone oil, 0.1-2.0% of modified POSS nanoparticles, 3-15% of surfactant, 0.1-2.0% of lubricant, 0.01-0.5% of defoaming agent, 0.01-0.5% of antistatic agent and 40-80% of deionized water.

2. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the modified silicone oil is one or more of amino modified silicone oil, polyether modified silicone oil and epoxy modified silicone oil.

3. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the modified POSS nanoparticles are tetramethoxy cage oligomeric silsesquioxanes.

4. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the surfactant is one or more of fatty alcohol polyoxyethylene ether type, alkylphenol polyoxyethylene ether type and polysorbate type.

5. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the lubricant is one or more of stearic acid, oleic acid, methyl laurate and fatty acid methyl ester.

6. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the defoaming agent is an organic silicon water-based defoaming agent.

7. The aqueous PAN precursor oil agent containing modified POSS nanoparticles as claimed in claim 1, wherein: the antistatic agent is one or more of fatty alcohol ether phosphate, phenol ether phosphate, fatty alcohol ether phosphate potassium salt, phenol ether phosphate potassium salt and octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

8. The preparation method of the aqueous PAN precursor oil agent containing the modified POSS nanoparticles as claimed in claim 1 comprises the following specific steps:

step A: adding 15-40% of modified silicone oil by mass into a flask, starting stirring, keeping the temperature of the flask constant to 30-35 ℃, and stirring for 10-30 min;

and B: after the temperature is constant, adding 3-15% by mass of surfactant, 0.1-2.0% by mass of lubricant, 0.01-0.5% by mass of defoaming agent and 0.01-0.5% by mass of antistatic agent into a flask, and stirring for more than 30 minutes by using a stirrer at a stirring speed of 1000-1500 rpm;

and C: adding 0.1-2.0 mass percent of modified POSS nano particles into deionized water with the mass percent of 40-80%, ultrasonically dispersing for 60-120 min, adding the mixture into a flask through a peristaltic pump after uniform dispersion, and finishing the addition within 60-180 min to obtain the aqueous PAN precursor oil agent containing the modified POSS nano particles.

Technical Field

The invention mainly relates to the technical field of PAN-based carbon fiber precursor oiling agents, and mainly relates to a water-based PAN precursor oiling agent containing modified POSS (polyhedral oligomeric silsesquioxane) nanoparticles and a preparation method thereof.

Background

The carbon fiber has excellent performances of high strength, light weight, fatigue resistance and the like, so that the high-performance composite material prepared by taking the carbon fiber as the reinforcing material is widely applied to various advanced technical fields of aviation, aerospace and the like, and becomes one of main reinforcing fibers of advanced composite materials. Polyacrylonitrile (PAN) precursor is one of the most important precursors for carbon fibers. In the production process of carbon fiber, precursor is a key factor influencing the quality of products, that is, only high-performance polyacrylonitrile precursor can produce high-performance carbon fiber. The oil agent is an important auxiliary agent for producing high-performance precursor and carbon fiber. The novel composite fiber is uniformly formed into a film on the surface of a protofilament, so that the adhesion and doubling between monofilaments can be prevented, and the friction and abrasion between the fiber surface and a roller in the production process can also be prevented, so that the defect on the fiber surface is effectively avoided, and the novel composite fiber is one of effective technical measures for improving the performances of the protofilament and the carbon fiber.

Polyhedral oligomeric silsesquioxane (POSS), a nanostructure with symmetry, is a typical organic-inorganic hybrid material. It consists of an inorganic framework formed by three-dimensional Si-O-Si short chains and organic substituents which completely cover the inorganic framework, integrates the superior performances of organic components and inorganic components, and has new performance generated by the synergistic effect of the organic components and the inorganic components. Each POSS particle contains one or more organic reactive functional groups that can undergo polymerization, grafting, surface bonding, and other reactions. The modified POSS nano-particles can be dissolved in a solvent and a resin, so that the dispersion of molecules is ensured, and the modified POSS nano-particles can be connected to an organic chain in a chemical bonding mode, so that the mechanical strength and the stability of the material are greatly improved. The modified POSS nano-particle is a hollow closed or semi-closed cage, has low density and good gas permeability, and has the small-size effect, the surface effect and the interface effect of common nano-ions, thereby showing special thermodynamic properties.

In the production process of the PAN precursor, the use of the oiling agent has important influence on the hydrophilicity, the convergence, the fiber separation, the filament rate of the precursor and the like of the PAN precursor. If the heat resistance of the oil agent is poor, the protofilament is sticky, the quality of the protofilament is reduced, fuzzing, winding and breaking are easily caused in the production and processing process of the protofilament, and the product performance of the final carbon fiber is affected.

In recent years, PAN yarn finishes such as CN 201010228253, CN 20110300362, and CN20110301144 are reported, and the performance of the finishes is improved by adjusting the type of modified silicone oil and the types of emulsifiers and auxiliaries, but the improvement degree of the performance is limited. For example, in patent CN 20171105013, a specific compound is added into a modified silicone oil system, and the specific compound is selected from one or more of amyl polyol ester, trimethylolpropane oleate, polyoxyethylene castor oil ester and pentaerythritol oleate, and is mainly used for producing a crosslinked mesh coating layer at a high temperature, so as to reduce the damage to the filaments caused by friction in the process, but the preparation process and the application mode are complicated.

The defects of the carbon fibers are mainly defects and damages caused by the micropores of the carbon fibers and adhesion between monofilaments. After PAN polymerization liquid is spun, the fiber is drawn in warm water, the precursor has high swelling degree, a large amount of micropore defects exist on the surface layer of the fiber, an oiling agent easily permeates into the surface layer and the interior of the fiber in a subsequent oiling process, and collapse of micropores is hindered in a drying and densification process, and the micropore defects serving as the precursor become the defects of carbon fibers after heat treatment, so that the carbon fibers have more micropore defects, and the comprehensive performance of the carbon fibers is influenced. The prior art does not achieve satisfactory effects on penetration and penetration of the finish into the fiber.

Disclosure of Invention

In order to solve the problems, the invention provides a water-based PAN precursor oil agent containing modified POSS nano particles and a preparation method thereof, and the specific technical scheme is as follows:

the water-based PAN precursor oil agent containing the modified POSS nano particles comprises 15-40% of modified silicone oil, 0.1-2.0% of modified POSS nano particles, 3-15% of surfactant, 0.1-2.0% of lubricant, 0.01-0.5% of defoaming agent, 0.01-0.5% of antistatic agent and 40-80% of deionized water.

The conductivity of the deionized water is less than or equal to 1 mu s/cm, the particle size of the water-based PAN precursor oiling agent is 50-350 nm, and the surface tension is 18-30 mN/m.

A modified POSS nano particle is introduced into a PAN precursor oil agent, and the POSS nano particle is modified and contains a hydrophilic functional group, does not need a dispersing agent and can be directly added into deionized water.

As a further improvement, the modified silicone oil is one or more of amino modified silicone oil, polyether modified silicone oil and epoxy modified silicone oil, wherein the modification amount of the amino modified silicone oil is 0.05-10%, the modification amount of the polyether modified silicone oil is 5-80%, and the modification amount of the epoxy modified silicone oil is 0.05-10%.

As a further improvement, the modified POSS nano particle is tetramethoxy cage type oligomeric silsesquioxane, is a symmetrical nano structure, is a polyhedral organic-inorganic doped compound, contains hydrophilic functional groups, is similar to the structure of modified silicone oil in an oil agent, is easy to emulsify and has good emulsion stability.

As a further improvement, the surfactant is one or more of fatty alcohol polyoxyethylene ether type, alkylphenol polyoxyethylene ether type and polysorbate type.

As a further improvement, the lubricant is one or more of stearic acid, oleic acid, methyl laurate and fatty acid methyl ester.

As a further improvement, the defoaming agent is a silicone water-based defoaming agent.

As a further improvement, the antistatic agent is one or more of fatty alcohol ether phosphate, phenol ether phosphate, fatty alcohol ether phosphate potassium salt, phenol ether phosphate potassium salt and octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

The preparation method of the aqueous PAN precursor oil agent containing the modified POSS nanoparticles comprises the following specific steps:

step A: adding 15-40% of modified silicone oil by mass into a flask, starting stirring, keeping the temperature of the flask constant to 30-35 ℃, and stirring for 10-30 min;

and B: after the temperature is constant, adding 3-15% by mass of surfactant, 0.1-2.0% by mass of lubricant, 0.01-0.5% by mass of defoaming agent and 0.01-0.5% by mass of antistatic agent into a flask, and stirring for more than 30 minutes by using a stirrer at a stirring speed of 1000-1500 rpm;

and C: adding 0.1-2.0 mass percent of modified POSS nano particles into deionized water with the mass percent of 40-80%, ultrasonically dispersing for 60-120 min, adding the mixture into a flask through a peristaltic pump after uniform dispersion, and finishing the addition within 60-180 min to obtain the aqueous PAN precursor oil agent containing the modified POSS nano particles.

The water-based PAN precursor oil agent containing the modified POSS nano particles is modified, contains hydrophilic functional groups, and has a siloxane structure similar to modified silicone oil, so that a dispersing agent is not needed, the preparation process is simplified, and the emulsion is stable. The modified POSS nano-particle integrates the superior performances of an organic component and an inorganic component and has a new performance generated by the synergistic effect of the organic component and the inorganic component. The modified POSS is introduced into an oil agent system, so that the bundling property of the PAN precursor can be obviously improved, the tensile strength of the precursor is improved, the modified POSS has better technological properties in the carbonization process, the tensile strength of the PAN carbon fiber is greatly improved, and the technological properties of carbon fiber production and the mechanical properties of the carbon fiber are effectively improved.

Experimental results show that the protofilament containing the modified POSS nano particles has better convergence, and is beneficial to the stability of the protofilament and a carbonization production process, the strength of the protofilament is improved by 3-5%, and the strength of carbon fiber is improved by 4-8%.

Monofilament damage can be caused by friction in the production process, and the use of the oiling agent can prevent the friction and abrasion between the fiber surface and a roller in the production process, thereby effectively avoiding the generation of defects on the fiber surface and being one of effective technical measures for improving the performances of precursor and carbon fiber; during the manufacturing process of the water-based PAN precursor oil agent containing the modified POSS nano particles, the modified POSS nano particles can effectively change the attachment state of the oil agent on fibers, the toughness of a protective film is increased, the oiling uniformity is improved, the oil agent is prevented from permeating into the surface layer and the interior of the fibers, and the performances of the precursor and the carbon fibers are improved. Because of the excellent heat resistance of the modified POSS nano particles, the modified POSS nano particles exist on the surface of the fiber together with the silicon oil agent in the pre-oxidation process, and the fusion and doubling among monofilaments are prevented. In addition, the modified POSS nano particles improve the friction force between fibers and increase the bundling property of the fibers, so that excellent processing performance in the carbonization process can be realized.

Modified POSS nano particles are added into the oiling agent, so that the heat resistance of the oiling agent can be effectively improved, and the quality of the precursor and the carbon fiber is improved when the precursor and the carbon fiber are produced. In the process of preoxidation and high-temperature carbonization of the protofilament, the oiling agent plays roles of preventing adhesion, preventing friction and abrasion among monofilaments, reducing friction between fibers and equipment, reducing broken filaments and the like, and effectively inhibits the generation of acquired defects of the protofilament. The protofilament oil agent containing the modified POSS nano particles can attach the nano particles to the surface of the protofilament, and the protofilament can be better protected due to the small size effect and the interface effect of the nano particles, so that the generation of new defects is prevented. The modified POSS nano particles are introduced into an oil agent system, so that the performance of an oil agent emulsion can be effectively improved, and the physical and chemical properties of the precursor and the carbon fiber are improved.

The invention has the beneficial effects that:

(1) the modified POSS nano particles are introduced into the aqueous PAN precursor oil agent, the POSS in the invention is a polyhedral structure organic-inorganic doped compound, is modified and contains hydrophilic functional groups, the defect that the nano particles are difficult to uniformly disperse and blend in a matrix due to self aggregation is overcome, a dispersing agent is not needed, the process is simplified, the emulsion is stable, and the preparation and the storage are convenient.

(2) The modified POSS nano particle consists of an inorganic framework formed by three-dimensional Si-O-Si short chains and an organic substituent group which completely covers the inorganic framework, and the structure of the modified POSS nano particle is similar to that of modified silicone oil. In the production of the raw silk, the heat resistance and the friction resistance of the PAN raw silk oiling agent are improved, and the convergence and the mechanical property of the PAN raw silk are improved.

(3) Compared with non-nanoparticle aqueous PAN precursor oiling agents, experimental results show that the precursor containing the modified POSS nanoparticles has better convergence, the stability of the precursor and a carbonization production process is facilitated, the strength of the precursor is improved by 3% -5%, and the strength of carbon fibers is improved by 4% -8%.

Detailed Description

In order to enhance the understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for the purpose of illustration only and are not intended to limit the scope of the present invention.