【摘要】：全氟聚醚具有化學(xué)惰性、不燃性、低表面張力等特點而被廣泛應(yīng)用于特種化合物改性和高端潤滑油領(lǐng)域,但目前國內(nèi)全氟聚醚產(chǎn)品幾乎全部依賴進口。本文以六氟環(huán)氧丙烷(HFPO)為原料,開發(fā)了陰離子聚合法合成全氟聚醚工藝,并制備出高性能真空泵油。首先考察了不同凈化劑組合的凈化效果及吸附容量,無水氯化鈣-3A分子篩-氧化鈣-活性氧化鋁組合可以將原料HFPO中的HF、水、六氟丙酮含量分別降低至500 μg/g、2μg/g、300 μg/g,滿足聚合反應(yīng)的要求。論文分析了六氟環(huán)氧丙烷陰離子聚合反應(yīng)的反應(yīng)機理,表明鏈增長過程為反應(yīng)速率的控制步驟,鏈轉(zhuǎn)移和鏈再生過程決定了全氟聚醚的聚合度,反應(yīng)過程中維持低單體濃度有利于獲得高平均分子量的聚合產(chǎn)物。從反應(yīng)工程角度考察了單次進料反應(yīng)器、分批進料反應(yīng)器和連續(xù)反應(yīng)器對聚合反應(yīng)過程的影響。在連續(xù)反應(yīng)器中,單體濃度低、休眠體濃度高、活性體濃度低,有利于聚合反應(yīng)向高聚合度方向進行。優(yōu)化的聚合反應(yīng)工藝條件為:在連續(xù)反應(yīng)器中,以CsF/DG為催化劑體系,在劑料摩爾比1:60,反應(yīng)溫度-60℃、停留時間72 h條件下,制得平均聚合度為20.0,平均分子量為3325 g/mol的全氟聚醚,收率達(dá)到99.2%。論文還建立了六氟環(huán)氧丙烷陰離子聚合反應(yīng)的反應(yīng)動力學(xué)模型,模擬了不同工藝條件下的聚合反應(yīng)過程。為了獲得穩(wěn)定化的全氟聚醚產(chǎn)物,采用堿水解法高效脫除全氟聚醚酰氟端基,獲得全氟聚醚油,避免了氟化鋁直接催化法的羰基轉(zhuǎn)化問題。優(yōu)化的穩(wěn)定化工藝條件為:KOH/二乙二醇水溶液:全氟聚醚=1:3、反應(yīng)溫度100℃,反應(yīng)時間6 h,再加入2%的A1F3,在250℃反應(yīng)8 h,得到穩(wěn)定化的全氟聚醚油。在減壓條件下蒸餾切割,獲得了不同分子量的窄餾分作為潤滑油基礎(chǔ)油。油品性質(zhì)指標(biāo)測試和真空性能評價結(jié)果表明,200-250℃以及250℃的餾分均可作為不同牌號的高端真空泵油。
[Abstract]:Perfluoropolyether is widely used in the field of special compound modification and high-end lubricating oil because of its chemical inert, noncombustibility and low surface tension. But at present, the domestic perfluoropolyether products almost rely on imports. In this paper, perfluoropolyether was synthesized by anion polymerization from hexafluoroethylene propylene oxide (HFPO) and high performance vacuum pump oil was prepared. Firstly, the purification efficiency and adsorption capacity of different combinations of purifying agents were investigated. Anhydrous calcium chloride 3A molecular sieve, calcium oxide and active alumina could reduce the content of HF, water in raw material HFPO to 500 渭 g / g of hexafluoroacetone, respectively, and the content of hexafluoroacetone could be reduced to 2 渭 g / g of hexafluoroacetone, respectively. 300 渭 g / g, meeting the requirements of polymerization. The reaction mechanism of anionic polymerization of hexafluoroethylene oxide was analyzed in this paper. It was shown that the chain growth process was the control step of reaction rate and chain transfer and chain regeneration process determined the degree of polymerization of perfluoropolyether. Maintaining low monomer concentration in the reaction process is beneficial to the polymerization products with high average molecular weight. From the point of view of reaction engineering, the effects of single feed reactor, batch feed reactor and continuous reactor on the polymerization process were investigated. In the continuous reactor, the monomer concentration is low, the dormant concentration is high, and the active agent concentration is low, which is favorable to the polymerization in the direction of high degree of polymerization. The optimum polymerization conditions are as follows: in a continuous reactor, with CsF/DG as catalyst system, the average polymerization degree is 20.0 at molar ratio of 1: 60, reaction temperature of -60 鈩，

本文編號：2330886