第26卷第4期化學(xué)反應(yīng)工程與工藝Vol 26, No 42010年8月Chemical Reaction Engineering and TechnologyAug.2010文章編號:1001-7631(2010)04-0376-05研究簡報(bào)焦磷酸丁酯的水解動力學(xué)周劍秋袁慎峰尹紅陳志榮浙江大學(xué)化學(xué)工程與生物工程學(xué)系,浙江杭州310027)摘要:以五氧化二磷和正丁醇反應(yīng)合成的混合磷酸酯為原料,考察了在50~80℃下焦磷酸正丁酯及焦磷酸二正丁酯的水解反應(yīng),并建立了焦磷酸正丁酯及焦確酸二正丁酯的水解反應(yīng)速率方程,結(jié)果表明:對焦確酸正丁酯,反應(yīng)級數(shù)為148,表觀活化能為7291kJ/mo,指前因子為224x100u2/(mo2a·h);對焦磷酸二正丁酯,反應(yīng)級數(shù)為123,表觀活化能為8502k/mol,指前因子為1.79×10ua/(mo}#·b)。通過實(shí)驗(yàn)數(shù)據(jù)擬合獲得了動力學(xué)方程,其焦磷酸正丁酯和焦磷酸二正丁酯轉(zhuǎn)化率的計(jì)算值和實(shí)驗(yàn)值吻合較好,具有可靠性,關(guān)鑣調(diào):焦磷酸正丁酯;焦碉酸二正丁;水解;動力學(xué)中圖分類號:0643.1文獻(xiàn)標(biāo)識碼:A磷酸酯鹽類陰離子型抗靜電劑水溶性好、起泡性小,具有良好的耐熱性、耐酸堿性和抗靜電性,可以滿足高速紡絲工藝的要求,且制備工藝相對簡單,成本較低1-3。工業(yè)上通常采用磷酸化試劑與羥基化合物反應(yīng)合成磷酸酯,常用的磷酸化試劑有磷酸、三氯氧磷、三氯化磷、五氧化二磷和焦磷酸等。磷酸化產(chǎn)物一般以混合物形式存在,主要組分有磷酸、磷酸單酯、磷酸雙酯和焦磷酸及其酯。羥基化合物與不同的磷酸化試劑反應(yīng)的機(jī)理不同,得到磷酸酯的結(jié)構(gòu)組成也不同。磷酸酯型抗靜電劑的結(jié)構(gòu)對紡絲油劑性能具有決定性的影響。焦磷酸鹽的抗靜電性和滲透性很差,其含量過高會嚴(yán)重影響產(chǎn)品性能,因此必須將副產(chǎn)物焦磷酸酯水解為磷酸酯。日前對混合磷酸酯中焦磷酸酯的水解動力學(xué)研究較少,為此,本工作研究了焦磷酸丁酯的水解反應(yīng)動力學(xué),以期對磷酸酯類抗靜電劑的生產(chǎn)提供技術(shù)指導(dǎo)。實(shí)驗(yàn)部分1.1混合磷酸酯合成在氮?dú)獗Ｗo(hù)下,將一定量的正丁醇加入到裝有機(jī)械攪拌器和溫度計(jì)的250mL三口燒瓶中,并分批加入一定量的五氧化二磷,控制體系溫度不超過40℃。五氧化二磷加料完畢后,于恒溫油浴中攪拌加熱至所需反應(yīng)溫度,反應(yīng)結(jié)束后得到無色透明液體。采用 Avance DMX500核磁共振儀,利用磷譜法(PNMR波譜法)分析產(chǎn)物組成,采用面積歸一法計(jì)算的結(jié)果與實(shí)際配比接近,偏差不超過3%,且重復(fù)性良好。分析溫度為27℃,樣品中05mL氘代二甲基亞砜( d-DMSO)含有0.05g磷原子1.2焦磷酸酯水解將30.0g混昆合瞬酸酯加人到裝有溫度計(jì)和磁力攪拌YH中國煤化工溫油浴中攪拌CNMHG收稿日期:201004-14;修訂日期:20100503作者簡介:周劍秋(1981-),男,碩士研究生;慎峰(1977-),男,教授,通訊聯(lián)系人. E-mail: sfc咖u第26卷第4期周劍秋等.焦磷酸丁酯的水解動力學(xué)77加熱至水解溫度,并加入2.40g相同溫度的蒸餾水,開始計(jì)時(shí),每隔一段時(shí)間取樣,采用核磁磷譜法分析其組成,并采用ZKF-1卡爾費(fèi)休水分測定儀分析水分含量。2反應(yīng)動力學(xué)模型建立水解反應(yīng)如下HO-P-O--P-OR +H2OHO--P--OR + PO.OHOHRO-PO-P-OR +H2O-2 HO-P-OROH OH其中,R為nCH,A,B和W分別表示焦磷酸正丁酯、焦磷酸二正丁酯和水?？紤]到水解反應(yīng)的特點(diǎn),假設(shè)水解反應(yīng)動力學(xué)模型符合冪函數(shù)形式以A=kCA"Cw嗎kBCBC其中:CA,CB和Cw分別指焦磷酸正丁酯、焦磷酸二正丁酯和水的物質(zhì)的量濃度;kA和kB為反應(yīng)速率常數(shù);n1,n2,m1和m2分別是水解反應(yīng)對焦磷酸正丁酯、焦磷酸二正丁酯和水的反應(yīng)級數(shù)CA,CB和Cw的計(jì)算如下:CA=CAO (1-XA)CB=CBo(1-XB)Cw=Cwo(1-Xw)其中,XA,XB和Xw為焦磷酸正丁酯、焦磷酸二正丁酯和水的轉(zhuǎn)化率。故式(1)和式(2)可變?yōu)?d(1-XA(1-XA)(1-Xd(1-X)=k(1-XB)(1-Xw)嗎其中:中國煤化工kA=kACA-1Cw嗎CNMHG(8)kB= kBCBo2-ICwom"(9)378化學(xué)反應(yīng)工程與工藝2010年8月3動力學(xué)模型求解不同反應(yīng)溫度下焦磷酸正丁酯、焦磷酸二正丁酯和水的轉(zhuǎn)化率隨時(shí)間的變化見圖1。8c圖1反應(yīng)物轉(zhuǎn)化率隨時(shí)間的變化Fig. 1 Conversion of reactants vs time at different temperature3.1反應(yīng)級數(shù)確定反應(yīng)級數(shù)的確定主要采用積分法和微分法。采用微分法求解動力學(xué)參數(shù)需先采用差分法或擬合法求出不同時(shí)刻對應(yīng)的反應(yīng)速率,會引人新的誤差,計(jì)算結(jié)果隨機(jī)性大,可靠性差,故本研究采用積分法確定反應(yīng)級數(shù)。結(jié)合 Matlab軟件中的四階 Runge-Kutta法和最小二乘法,計(jì)算不同溫度下的動力學(xué)參數(shù),擬合目標(biāo)函數(shù)為實(shí)驗(yàn)值和計(jì)算值的均方偏差最小。F=∑A experimenta根據(jù)不同溫度下的實(shí)驗(yàn)數(shù)據(jù)擬合得到方程(6)和(7)中的n和m值,見表1?？梢?擬合得到的反應(yīng)級數(shù)非常接近。水解反應(yīng)級數(shù)取不同溫度下的平均值,對焦磷酸正丁酯,n為1.48,m1為1.80;對焦磷酸二正丁酯,n2為1.23,m2為1.99。衰1動力學(xué)參數(shù)的擬合值及F值Table 1 The kinetic parameters and F at different temperature501.456.78X108.43X10-609.01×10-51.22×10-2.14X10-43.49X10-41.03×10-4"凵中國煤化工2.59X10-4CNMHG焦磷酸正丁酯、焦磷酸二正丁酯和水的初始濃度分別為.4031,0.411和4.148mol/L。將已確定的反應(yīng)級數(shù)n1,n2,m和m2代人模型計(jì)算得到不同溫度下的反應(yīng)速率常數(shù),見表2。第26卷第4期周劍秋等,焦磷酸丁酯的水解動力學(xué)3792不同溫度下的反應(yīng)速率常數(shù)Table 2 Reaction constants at different temperatureT/C600.0940.1950.3320.0083.2表觀活化能根據(jù) Arrhenius方程k=kexp(一Ea/(RT)得Ink=lmk-Ea/(RT),以lnk-T1作圖,見R=09845圖2。由圖2擬合直線計(jì)算出焦磷酸正丁酯和酸二正丁酯水解反應(yīng)的指前因子(k)分別為2.24×100L23/(mol28·h)和1.79×101L22(mol2h),表觀活化能(Ea)分別為7291和85. 02 kJ/mol80285202953.003.053.Tx10/K焦磷酸正丁酯和焦磷酸二正丁酯的水解動力學(xué)方程分別為:圖2lmk與T-1的關(guān)系Fig 2 Relationship between Ink and T-上雌-2×19g2(10)=1,79×10exp(-5.02)cl2cmln(11)文獻(xiàn)0-12表明,P2O4-的水解受溶劑、磷原子初始濃度、pH值以及端基組成的影響,得出P2O4的水解為一級反應(yīng)。在水解過程中生成磷酸,pH值是變化的,對水解反應(yīng)形成自催化作用,因而可能導(dǎo)致焦磷酸正丁酯和焦磷酸二正丁酯的水解反應(yīng)級數(shù)偏離整數(shù)級。由方程(10)和(11)計(jì)算得焦磷酸正丁酯和焦磷酸二正丁酯的轉(zhuǎn)化率,并與其實(shí)驗(yàn)值比較,結(jié)果見圖3.計(jì)算值和實(shí)驗(yàn)值的均方偏差(F)分別為27×10和3.9×10-,相關(guān)系數(shù)分別為0.9917和0.9900,平均相對誤差分別為2%和3%。說明計(jì)算值與實(shí)驗(yàn)值吻合較好。1.0 n-buty pyrophosphate1.0 d-n-butyl pyrophosphateaaaa圖3水解動力學(xué)模型計(jì)算值與實(shí)驗(yàn)值比較Fig 3 Comparison of experimental and calculated values4結(jié)論中國煤化工考察了50~80℃下,焦磷酸正丁酯及焦磷酸二正丁CNMHG數(shù)據(jù)通過積分法確定反應(yīng)級數(shù),建立了焦磷酸正丁酯及焦磷酸二正丁酯H平刀性,共H棄值與實(shí)驗(yàn)值吻合較好。380化學(xué)反應(yīng)工程與工藝2010年8月參考文獻(xiàn):1楊毓瑩,戴伊萍,舒建生等.一種用于滌綸短纖維油劑的抗靜電劑,中國,CN1361324.20022楊海濤,周向東,丙綸POY高速紡絲油劑的研制.合成纖維,2004,33(6):36~38Yang Haitao, Zhou Xiangdong. The Study of High Speed Spinning Finish TF-730 for PP POY. Synthetic Fiber in China, 20043王文,牛予蓉,烷基磷酸酯鉀鹽抗靜電性及其吸濕性研究.糖細(xì)化工,2001,18(30);156~158Wang Wen, Niu Yurong. Study of the Antistatic and Hygroscopicity of the Potassium Salts of Alkyl Phosphate, Fine Chemicals18(30);156~1584曹向禹,吳平,黃君禮,磷酸化反應(yīng)及其在皮革中的應(yīng)用,當(dāng)代化工,2004,33(4):207~210Cao Xiangyu, Wu Ping, Huang Junli. Phosphating Reaction and Its Application in Leather Industry. Leather Chemicals, 200433(4):207~2105 Terence M P. Process for the Production of Anti-Static Thermoplastics Films and the Films Thereby Produced. Eur Pat6張君.高速紡絲油劑用抗靜電劑的合成及其構(gòu)性關(guān)系研究:〔學(xué)位論文〕.杭州:浙江大學(xué),20077夏婷,紡絲油劑用磷酸酯型抗靜電劑合成反應(yīng)機(jī)理研究:〔學(xué)位論文〕.杭州:浙江大學(xué),20088熊杰明,張麗萍,呂九琢,反應(yīng)動力學(xué)參數(shù)的計(jì)算方法與計(jì)算誤差.計(jì)算機(jī)與應(yīng)用化學(xué),203,20(1):159~162iong Jieming, Zhang Liping, Lv Jiuzhuo. Approaches and Their Deviations for Figuring out the Reactive Kinetics Parameters. Computersand Applied Chemistry, 2003, 20(1): 159-1629黃華江,實(shí)用化工計(jì)算機(jī)模擬 MATLAB在化工中的應(yīng)用,北京:化學(xué)工業(yè)出版社,2004.226~24310 Campbell D O, Kilpatrick M. A Kinetic Study of the Hydrolysis of Pyrophosphates. Journal of the American Chemical Society1954,76;893~90111 Williard J W, Kim Y K, Sullivan J M L Effect of Concentration upon the Hydrolysis Rate of Ammonium Pyrophosphate at 25 cJournal of Chemical and Engineering Data, 1984, 29(4):436-43812 McBeath M T, Lombi E, Mclaughlin M J, et al. Polyphosphate-Fertilizer Solution Stability with Time, Temperature, and PH.ournal of Plant Nutrition and Soil Science, 2007, 170(3)1 387-391Kinetics of Hydrolysis of Butyl PyrophosphateZhou Jianqiu Yuan Shenfeng Yin Hong Chen Zhirong(Department of Chemical Engineering and Biological Engineering, Zhejiang University, Hangzhou 310027, ChinaAbstract: Phosphate compounds were synthesized from phosphorus pentoxide and nbutanol. Thehydrolysis kinetics of n-butyl pyrophosphate and di-n-butyl pyrophosphate were investigated under50-80C and hydrolysis reaction rate equations were built up. The results showed that for -butylpyrophosphate, the reaction order was 1.48, the apparent activation energy was 72. 91 kJ/ mol and thepre-exponential factor was 2. 24 X 100 L 2/(mol- 2. h)and for di-n-butyl pyrophosphate, theeaction order was 1. 23, the apparent activation energy was 85. 02 kJ/mol, the pre-etial factorwas 1. 79X10LZ22(mol-22. h). The hydrolysis reaction rate equations of n-butyl pyrophosphateand di-nbutyl pyrophosphate were obtained by fitting the experimental data, The conversions ofn-butyl pyrophosphate and di-n-butyl pyrophosphate from the equations were in good agreement withthe experimental valuesKey words: n-butyl pyrophosphate; di-n-butyl pyropeTHE中國煤化工CNMHG