H_2O_2改性对聚丙烯腈原丝化学结构的影响
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摘要
为节省预氧化进程的能耗和时间并优化聚丙烯腈(PAN)预氧纤维的性能,用H_2O_2改性PAN原丝,使其提前环化。采用FTIR、XPS等方法表征不同处理温度获得的未改性和改性PAN原丝。结果表明:H_2O_2水溶液在60℃改性PAN原丝时,H_2O_2可引发氰基环化,末端环发生亚胺、烯胺互变异构,由此出现亚氰基、类芳香伯胺;改性温度越高,改性PAN原丝的亚氰基含量、共轭程度越大。在模拟稳定化过程中,改性PAN原丝的类芳香伯胺可在较低温度下引发相邻氰基环化。使用氨水(NH3·H2O)作为助剂获得改性PAN原丝,与未改性PAN原丝经历相同的预氧化进程,改性后的PAN原丝能在较短时间内达到适合的预氧化程度,且PAN预氧纤维径向结构的均匀性被改善,由此获得热稳定性更高的PAN预氧纤维。
In order to save energy consumption and time of the pre-oxidation process and optimize the performance of polyacrylonitrile(PAN)pre-oxidized fiber,PAN precursor could cyclize in advance with modification with H_2O_2.The unmodified and modified PAN precursor treated at different temperatures was analyzed by FTIR and XPS,et al.The results show that the modification with H_2O_2 aqueous solution at 60℃induces nitrile of the PAN precursor to cyclize and terminal ring structure tautomerizes,hence it brings about imine and quasi-aromatic primary amine.With the increase of the modification temperature,the content and conjugation degree of the imine of modified PAN precursor is promoted.In the process of the simulated stabilization,quasi-aromatic primary amine of the modified PAN precursor could induce adjacent nitrile to cyclize at lower temperature.The modified PAN precursor with NH3·H2 O as additives experiences the same pre-oxidation process as the unmodified PAN precursor.The former can reach suited pre-oxidation degree within a short time and the radial structure of PAN pre-oxidized fiber becomes more uniform,so that the PAN pre-oxidized fiber which has higher thermostability can be obtained.
In order to save energy consumption and time of the pre-oxidation process and optimize the performance of polyacrylonitrile(PAN)pre-oxidized fiber,PAN precursor could cyclize in advance with modification with H_2O_2.The unmodified and modified PAN precursor treated at different temperatures was analyzed by FTIR and XPS,et al.The results show that the modification with H_2O_2 aqueous solution at 60℃induces nitrile of the PAN precursor to cyclize and terminal ring structure tautomerizes,hence it brings about imine and quasi-aromatic primary amine.With the increase of the modification temperature,the content and conjugation degree of the imine of modified PAN precursor is promoted.In the process of the simulated stabilization,quasi-aromatic primary amine of the modified PAN precursor could induce adjacent nitrile to cyclize at lower temperature.The modified PAN precursor with NH3·H2 O as additives experiences the same pre-oxidation process as the unmodified PAN precursor.The former can reach suited pre-oxidation degree within a short time and the radial structure of PAN pre-oxidized fiber becomes more uniform,so that the PAN pre-oxidized fiber which has higher thermostability can be obtained.
引文
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[3] MITTAL J,MATHUR R B,BAHL O P,et al.Post spinning treatment of PAN fibers using succinic acid to produce high performance carbon fibers[J].Carbon,1998,36(7):893-897.
[4] OUYANG Q,WANG H J,CHENG L,et al.Effect of boric acid on the stabilization of poly(acrylonitrile-co-itaconic acid)[J].Journal of Polymer Research,2007,14(6):497-503.
[5]王延相,王成国,张旺玺,等.化学表面处理对PAN预氧纤维的影响[J].金山油化纤,2002,21(1):5-9.WANG Y X,WANG C G,ZHANG W X,et al.The influences of chemical surface treatment on PAN pre-oxidized fibers[J].Jinshang Fiber,2002,21(1):5-9(in Chinese).
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[10] COLLINS G L,THOMAS N W,WILLIAMS G E.Kinetic relationships between heat generation and nitrile consumption in the reaction of poly(acrylonitrile)in air at 265℃[J].Carbon,1988,26(5):671-679.
[11]冯闻,肖士洁,昌志龙,等.PAN大分子预氧化结构形成及演变机理[J].北京化工大学学报:自然科学版,2011,38(4):58-63.FENG W,XIAO S J,CHANG Z L,et al.Evolution of PAN macromolecular structural transformations during pre-oxidative stabilization[J].Journal of Beijing University of Chemical Technology:Natural Science,2011,38(4):58-63(in Chinese).
[12] GRASSIE N,MCGUCHAN R.Pyrolysis of polyacrylonitrile and related polymers-IV.Thermal analysis of polyacrylonitrile in the presence of additives[J].European Polymer Journal,1971,7(11):1503-1541.
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[14]翁诗甫.傅里叶变换红外光谱分析(第二版)[M].北京:化学工业出版社,2010.WENG S F.Fourier translation infrared spectroscopy analysis(II)[M].Beijing:Chemical Industry Press,2010(in Chinese).
[15]齐帅,李常清,贾龙飞,等.溶解法分级聚丙烯腈纤维精细结构[J].高分子材料科学与工程,2017,33(4):29-34.QI S,LI C Q,JIA L F,et al.Fine structure of polyacrylonitrile fibers classified by dissolution method[J].Polymer Materials Science and Engineering,2017,33(4):29-34(in Chinese).
[16] LEI S,CAO W Y,FU Z Y,et al.The conjugated plane formed in polyacrylonitrile during thermal stabilization[J].Journal of Applied Polymer Science,2016,133(36):43890.
[17] WU G P,LU C X,WU X P,et al.X-ray photoelectron spectroscopy investigation into thermal degradation and stabilization of polyacrylonitrile fibers[J].Journal of Applied Polymer Science,2004,94(4):1705-1709.
[18] KRZYSZTOF S.Temperature-time sieve-A case of nitrogen in coal[J].Energy&Fuel,2004,18(2):405-409.
[19] RAYMUNDO P E,CAZORLA A D,LINARES S A,et al.Structural characterization of N-containing activated carbon fibers prepared from a low softening point petroleum pitch and a melamine resin[J].Carbon,2002,40(4):597-608.
[20]禹凡.PAN纤维含氮结构的演变[D].北京:北京化工大学,2015.YU F.Evolution of nitrogen structure in PAN fibers[D].Beijing:Beijing University of Chemical Technology,2015(in Chinese).
[21]罗莎,高爱君,王统帅,等.PAN纤维高温环境下氮结合态演变规律的研究[J].化工新型材料,2012,40(1):84-87.LUO S,GAO A J,WANG T S,et al.Research on evolution of the combination state of N in PAN fibers in high-temperature environment[J].New Chemical Materials,2012,40(1):84-87(in Chinese).
[22]张琪,华鲁,雷帅,等.聚丙烯腈纤维烯胺结构的形成及其氧化特性的研究[J].高科技纤维与应用,2014,39(2):24-28.ZHANG Q,HUA L,LEI S,et al.The formation and oxidation property of the enamine during the stabilization of polyacrylonitrile fiber[J].Hi-Tech Fiber&Application,2014,39(2):24-28(in Chinese).
[23]肖士洁.聚丙烯腈热稳定化反应机理及动力学研究[D].北京:北京化工大学,2012.XIAO S J.Mechanism and kinetics during thermal stabilization of polyacrylonitrile[D].Beijing:Beijing University of Chemical Technology,2012(in Chinese).
[24] COLEMAN M M,PETCAVICH R J.Fourier transform infrared studies on the thermal degradation of polyacrylonitrile[J].Journal of Polymer Science:Polymer Physics Edition,1978,16(5):821-832.
[25]刘杰,王新文,马兆昆,等.热氧稳定化过程温度效应对PAN纤维径向氧元素扩散速率的作用[J].复合材料学报,2012,29(2):26-33.LIU J,WANG X W,MA Z K,et al.Function of temperature effect on the radial pervasion of oxygen elements during the stabilization of polyacrylonitrile fibers[J].Acta Materiae Compositae Sinica,2012,29(2):26-33(in Chinese).
[26]钟珊,徐帆,雷帅,等.PAN预氧纤维径向结构的光密度法研究[J].材料工程,2017,45(2):65-71.ZHONG S,XU F,LEI S,et al.Optical density method of radial structure of PAN-based pre-oxidized fibers[J].Journal of Materials Engineering,2017,45(2):65-71(in Chinese).
[2]刘杰,禹化果,薛岩,等.聚丙烯腈纤维热应力与碳纤维结构及性能的关联性[J].复合材料学报,2014,31(1):66-72.LIU J,YU H G,XUE Y,et al.Relationship between the thermal stress of polyacrylonitrile fibers and the structure and properties of resulting carbon fibers[J].Acta Materiae Compositae Sinica,2014,31(1):66-72(in Chinese).
[3] MITTAL J,MATHUR R B,BAHL O P,et al.Post spinning treatment of PAN fibers using succinic acid to produce high performance carbon fibers[J].Carbon,1998,36(7):893-897.
[4] OUYANG Q,WANG H J,CHENG L,et al.Effect of boric acid on the stabilization of poly(acrylonitrile-co-itaconic acid)[J].Journal of Polymer Research,2007,14(6):497-503.
[5]王延相,王成国,张旺玺,等.化学表面处理对PAN预氧纤维的影响[J].金山油化纤,2002,21(1):5-9.WANG Y X,WANG C G,ZHANG W X,et al.The influences of chemical surface treatment on PAN pre-oxidized fibers[J].Jinshang Fiber,2002,21(1):5-9(in Chinese).
[6] POPOVSKA N,MLADENOV I.Untersuchungen zur herstellung von kohlenstoffasern auf der basis von mit wasserstoffperoxid modifizierten PAN-fasern[J].Carbon,1983,21(1):33-38.
[7] LIU L Q,CHEN H F,PAN D.Modification of polyacrylonitrile precursor fiber with hydrogen peroxide[J].Fibers and Polymers,2012,13(5):587-592.
[8]张国臣.过氧化氢的发展及应用[J].吉化科技,1997(1):30-37.ZHANG G C.The development and application of hydrogen peroxide[J].Jilin Science&Technology,1997(1):30-37(in Chinese).
[9]李崇俊,王华,徐永花,等.四元共聚及氨化改性PAN原丝及其碳纤维研究[J].高科技纤维与应用,2012,37(3):11-20.LI C J,WANG H,XU Y H,et al.A tetra-copolymerization and its ammoniating modification on PAN based precursors and carbon fibers[J].Hi-Tech Fiber&Application,2012,37(3):11-20(in Chinese).
[10] COLLINS G L,THOMAS N W,WILLIAMS G E.Kinetic relationships between heat generation and nitrile consumption in the reaction of poly(acrylonitrile)in air at 265℃[J].Carbon,1988,26(5):671-679.
[11]冯闻,肖士洁,昌志龙,等.PAN大分子预氧化结构形成及演变机理[J].北京化工大学学报:自然科学版,2011,38(4):58-63.FENG W,XIAO S J,CHANG Z L,et al.Evolution of PAN macromolecular structural transformations during pre-oxidative stabilization[J].Journal of Beijing University of Chemical Technology:Natural Science,2011,38(4):58-63(in Chinese).
[12] GRASSIE N,MCGUCHAN R.Pyrolysis of polyacrylonitrile and related polymers-IV.Thermal analysis of polyacrylonitrile in the presence of additives[J].European Polymer Journal,1971,7(11):1503-1541.
[13] CLARKE A J,BAILEY J E.Oxidation of acrylic fibers for carbon fiber formation[J].Nature,1973,243(5403):146-150.
[14]翁诗甫.傅里叶变换红外光谱分析(第二版)[M].北京:化学工业出版社,2010.WENG S F.Fourier translation infrared spectroscopy analysis(II)[M].Beijing:Chemical Industry Press,2010(in Chinese).
[15]齐帅,李常清,贾龙飞,等.溶解法分级聚丙烯腈纤维精细结构[J].高分子材料科学与工程,2017,33(4):29-34.QI S,LI C Q,JIA L F,et al.Fine structure of polyacrylonitrile fibers classified by dissolution method[J].Polymer Materials Science and Engineering,2017,33(4):29-34(in Chinese).
[16] LEI S,CAO W Y,FU Z Y,et al.The conjugated plane formed in polyacrylonitrile during thermal stabilization[J].Journal of Applied Polymer Science,2016,133(36):43890.
[17] WU G P,LU C X,WU X P,et al.X-ray photoelectron spectroscopy investigation into thermal degradation and stabilization of polyacrylonitrile fibers[J].Journal of Applied Polymer Science,2004,94(4):1705-1709.
[18] KRZYSZTOF S.Temperature-time sieve-A case of nitrogen in coal[J].Energy&Fuel,2004,18(2):405-409.
[19] RAYMUNDO P E,CAZORLA A D,LINARES S A,et al.Structural characterization of N-containing activated carbon fibers prepared from a low softening point petroleum pitch and a melamine resin[J].Carbon,2002,40(4):597-608.
[20]禹凡.PAN纤维含氮结构的演变[D].北京:北京化工大学,2015.YU F.Evolution of nitrogen structure in PAN fibers[D].Beijing:Beijing University of Chemical Technology,2015(in Chinese).
[21]罗莎,高爱君,王统帅,等.PAN纤维高温环境下氮结合态演变规律的研究[J].化工新型材料,2012,40(1):84-87.LUO S,GAO A J,WANG T S,et al.Research on evolution of the combination state of N in PAN fibers in high-temperature environment[J].New Chemical Materials,2012,40(1):84-87(in Chinese).
[22]张琪,华鲁,雷帅,等.聚丙烯腈纤维烯胺结构的形成及其氧化特性的研究[J].高科技纤维与应用,2014,39(2):24-28.ZHANG Q,HUA L,LEI S,et al.The formation and oxidation property of the enamine during the stabilization of polyacrylonitrile fiber[J].Hi-Tech Fiber&Application,2014,39(2):24-28(in Chinese).
[23]肖士洁.聚丙烯腈热稳定化反应机理及动力学研究[D].北京:北京化工大学,2012.XIAO S J.Mechanism and kinetics during thermal stabilization of polyacrylonitrile[D].Beijing:Beijing University of Chemical Technology,2012(in Chinese).
[24] COLEMAN M M,PETCAVICH R J.Fourier transform infrared studies on the thermal degradation of polyacrylonitrile[J].Journal of Polymer Science:Polymer Physics Edition,1978,16(5):821-832.
[25]刘杰,王新文,马兆昆,等.热氧稳定化过程温度效应对PAN纤维径向氧元素扩散速率的作用[J].复合材料学报,2012,29(2):26-33.LIU J,WANG X W,MA Z K,et al.Function of temperature effect on the radial pervasion of oxygen elements during the stabilization of polyacrylonitrile fibers[J].Acta Materiae Compositae Sinica,2012,29(2):26-33(in Chinese).
[26]钟珊,徐帆,雷帅,等.PAN预氧纤维径向结构的光密度法研究[J].材料工程,2017,45(2):65-71.ZHONG S,XU F,LEI S,et al.Optical density method of radial structure of PAN-based pre-oxidized fibers[J].Journal of Materials Engineering,2017,45(2):65-71(in Chinese).