CN-122012155-A - Preparation of polymethacrylate/alkyl naphthalene compound anticoagulant and application of polymethacrylate/alkyl naphthalene compound anticoagulant in synthesis of ester insulating oil

Abstract

The invention discloses a preparation method of a polymethacrylate/alkyl naphthalene compound anticoagulant and application of the polymethacrylate/alkyl naphthalene compound anticoagulant in synthetic ester insulating oil, and relates to the technical field of synthetic ester insulating oil. The invention mixes beta-naphthol and linear alpha-olefin, and obtains beta- (C10-C14 alkyl) naphthalene through alkylation reaction, then, the polymethacrylate is compounded with beta- (C10-C14 alkyl) naphthalene to obtain the polymethacrylate/alkyl naphthalene compound anticoagulant for insulating oil, wherein the polymethacrylate Mn=8000-12000 g/mol and PDI is less than or equal to 1.2, and the linear alpha-olefin is one or more of C10-C14 linear alpha-olefins. The invention realizes the remarkable improvement of the comprehensive performance of the synthetic ester insulating oil through the synergistic compounding design of the narrow-distribution polymethacrylate and the beta-alkyl naphthalene, and breaks through the technical problem that the existing anticoagulant is difficult to simultaneously consider the low-temperature fluidity, the oxidation stability and the insulating performance.

Inventors

• WANG FEIPENG
• LI SHI
• LI JIAN
• HUANG ZHENGYONG
• LI CHANGHENG
• ZHANG YINGFAN

Assignees

• 重庆大学

Dates

Publication Date

20260512

Application Date

20260203

Claims (10)

1. 1. The preparation method of the polymethacrylate/alkyl naphthalene compound anticoagulant for the insulating oil is characterized by comprising the following steps of: Beta-alkyl naphthalene is prepared by mixing beta-naphthol and linear alpha-olefin according to a molar ratio of 1:2-3, adding a catalyst to carry out alkylation reaction, and washing with alkali and water after the reaction is finished to obtain beta-alkyl naphthalene, namely beta- (C10-C14 alkyl) naphthalene; compounding, namely compounding the polymethacrylate and the beta- (C10-C14 alkyl) naphthalene according to the mass ratio of 2:1-4:1 to obtain the polymethacrylate/alkyl naphthalene compound anticoagulant for insulating oil; the number average molecular weight Mn=8000-12000 g/mol, the molecular weight distribution index PDI is less than or equal to 1.2; the linear alpha-olefin is one or more of C10-C14 linear alpha-olefins.
2. 2. The preparation method according to claim 1, wherein the alkylation reaction is carried out at a temperature of 170-190 ℃ for 4-6 hours, and the catalyst used in the alkylation reaction is concentrated sulfuric acid.
3. 3. The method according to claim 1, wherein when the linear alpha-olefin is a plurality of C10-C14 linear alpha-olefins, the molar ratio of C12 linear alpha-olefins in the linear alpha-olefins is not less than 40%.
4. 4. The preparation method of claim 1, wherein the beta-alkylnaphthalene is doped beta- (C10-C14 alkyl) naphthalene, and the preparation method of the polymethacrylate/alkylnaphthalene compound anticoagulant for insulating oil comprises the following steps: The preparation of doped beta- (C10-C14 alkyl) naphthalene comprises the steps of mixing beta-naphthol and the linear alpha-olefin according to a molar ratio of 1:2-3, adding a catalyst to carry out alkylation reaction, and carrying out alkaline washing and water washing on a reaction liquid to obtain beta- (C10-C14 alkyl) naphthalene; compounding, namely compounding the polymethacrylate and the doped beta- (C10-C14 alkyl) naphthalene according to the mass ratio of 2:1-4:1 to obtain the polymethacrylate/alkyl naphthalene compound anticoagulant for insulating oil.
5. 5. The method according to claim 4, wherein the doping amount of the short-chain alkyl group in the doped beta-alkylnaphthalene is less than or equal to 10%, and the short-chain alkyl group is C8 alkane.
6. 6. The polymethacrylate/alkyl naphthalene compound anticoagulant prepared by the preparation method of any one of claims 1-5.
7. 7. The use of the polymethacrylate/alkyl naphthalene compound anticoagulant according to claim 6 for anticoagulation of insulating oil.
8. 8. The use according to claim 7, wherein the total addition of the polymethacrylate/alkyl naphthalene compound anticoagulant in the insulating oil is less than or equal to 1.5 wt%, the insulating oil is synthetic ester oil insulating oil, and the synthetic ester oil insulating oil comprises pentaerythritol tetraoctanoate.
9. 9. A synthetic ester insulating oil comprising the polymethacrylate/alkyl naphthalene compound anticoagulant of claim 6.
10. 10. The method for preparing a synthetic ester insulating oil according to claim 9, comprising the steps of: adding the polymethacrylate/alkyl naphthalene compound anticoagulant into the synthetic ester oil insulating oil, and dispersing.

Description

Preparation of polymethacrylate/alkyl naphthalene compound anticoagulant and application of polymethacrylate/alkyl naphthalene compound anticoagulant in synthesis of ester insulating oil Technical Field The invention relates to the technical field of synthetic ester insulating oil, in particular to preparation of a polymethacrylate/alkyl naphthalene compound anticoagulant and application of the polymethacrylate/alkyl naphthalene compound anticoagulant in the synthetic ester insulating oil. Background The insulating oil is a core functional medium of power transmission and transformation equipment such as transformers, reactors and the like, and is required to simultaneously bear the key tasks of insulation, heat dissipation, fault arc suppression and the like. The traditional mineral insulating oil is widely applied by virtue of the advantages of high dielectric strength and low cost, but under severe working conditions such as high cold, high load and the like, the inherent defects of the traditional mineral insulating oil are gradually highlighted, firstly, the pour point of the mineral oil is generally higher than-30 ℃, the viscosity of the mineral oil is greatly increased in a low-temperature environment, the oil circulation efficiency is greatly reduced, local overheating and even insulation failure of equipment are easily caused, secondly, the free radical chain reaction generated by thermal oxidation in the operation process is difficult to inhibit, the aging of the oil is accelerated, carboxylic acid substances are generated, the equipment insulating paper is corroded, the service life of the equipment is obviously shortened, furthermore, the biodegradability of the mineral oil is extremely low, the environmental retention time can even exceed decades, the soil and water pollution are easily caused after leakage, and the urgent requirement of the global power transmission and transformation industry on green sustainable development is difficultly met. In order to break through the technical bottleneck, the synthetic ester insulating oil (such as polyol ester and complex ester) realizes performance jump through molecular structure design, and has the characteristics of biodegradability (degradation rate >90% under OECD 301B standard), high ignition point (300 ℃) and long oxidation induction period (120 h@120 ℃), and the like which are obviously superior to those of mineral oil, thus becoming the main stream research and development direction of environment-friendly insulating oil. However, the existence of polar ester groups in the synthetic ester molecules enables the polar ester groups to easily form an ordered crystallization network through hydrogen bonding at low temperature, and even though the basic formula is optimized, the pour point of typical products is still limited to-40 ℃ to-45 ℃, and the severe requirements of power transmission and transformation equipment in extremely cold areas (such as-55 ℃ to-60 ℃) on the low-temperature fluidity of oil products cannot be met. In the prior art, the improvement of the low-temperature performance of the synthetic ester mainly depends on a single-component anticoagulant, wherein one type of the anticoagulant is a polymethacrylate polymer, crystallization is inhibited through a steric hindrance effect, but when the addition amount exceeds 1.5wt%, the breakdown voltage of an oil product is reduced by more than 15% due to entanglement of molecular chains, and the insulation safety of equipment is seriously threatened, and the other type of the anticoagulant is an alkylbenzene aromatic compound, although the crystallization phase transition temperature can be reduced to improve the low-temperature fluidity, the free radical quenching capability is insufficient, the oxidation stability of the oil product cannot be cooperatively improved, and the short-chain alkylbenzene derivative faces strict environmental protection regulation restriction due to the existence of ecological toxicity disputes. Therefore, developing a compound anticoagulant system which can achieve low-temperature fluidity enhancement and oxidation stability synergistic enhancement without damaging the inherent insulating property of the synthetic ester has become a key technical challenge for breaking through the environmental protection type insulating oil extremely cold application barrier and pushing the compound anticoagulant system to replace the traditional mineral oil on a large scale. Disclosure of Invention The invention aims to provide preparation of a polymethacrylate/alkyl naphthalene compound anticoagulant and application of the polymethacrylate/alkyl naphthalene compound anticoagulant in synthesizing ester insulating oil, so as to solve the problems in the prior art. In order to achieve the above object, the present invention provides the following solutions: The invention provides a preparation method of a polymethacrylate/alkyl naphthalene compound anticoagulant for insul