预氧化是制备碳纤维非常重要的一个环节,制得预氧化丝的性能直接决定最终碳纤维的性能,因此研究预氧化过程对预氧化丝结构性能的影响规律具有重要意义。通过广角X射线衍射点光源取向测试和小角X射线散射实验,计算得到了聚丙烯腈(PAN)基碳纤维原丝与不同处理时间下预氧丝取向度、线结晶度、长周期L、晶区厚度Lc、无定形区厚度La等微观结构参数。采用元素分析仪和单纤维强力仪研究了该系列PAN基碳纤维原丝、预氧丝的元素组成和力学性能随预氧化时间的变化,明确了PAN基碳纤维预氧丝内部微观结构参数、元素含量与其力学性能的关系。
Carbon fiber (CF) have been widely applied in many areas,for instance aerospace,traffic and transportation,sports leisure and etc.Preoxidation is very important process for preparing CF with high performance,which is closely related with the performance of preoxidized fibers.Therefore,it is important and promising to reveal the relationship between preoxidation and preoxidized fibers performance.Wide angle X-ray diffraction and small angle X-ray scattering were used to detect and calculated the orientation,crystallinity,long-periodic (L),thickness of crystalline (Lc) and thickness of amorphous (La) of polyacrylonitrile precursor fiber (PAN fiber) and different preoxidized fibers.Elemental analysis and single fiber strength tester were performed to investigate the change of fiber tenacity with elements composition for PAN fibers and preoxidizer fibers.The relationship between fiber microstructure,element and strength was fully revealed.
[1] Hammersley A P.FIT2D:a multi-purpose data reduction,analysis and visualization program[J].Journal of Applied Crystallography,2016,49:646-652.
[2] 贺福.碳纤维及其应用技术[M].北京:化学工业出版社,2004,269-285.
[3] Wang Y,Yin W Y.Chemical modification for PAN fibers during heat-treatment process[J].Physics Procedia,2011,18:202-205.
[4] Sauder C,Lamon J,Pailler R.The tensile behavior of carbon fibers at high temperatures up to 2400℃[J].Carbon,2004,42(4):715-725.
[5] Rahaman M S A,Ismail A F,Mustafa A.A review of heat treatment on polyacrylonitrile fiber[J].Polymer Degradation and Stability,2007,92(8):1421-1432.
[6] 谭婷婷,王成国,井敏,等.PAN基碳纤维的微观组织结构与力学性能关系研究[J].功能材料,2012,43(16):2226-2230.
[7] 朱育平,陈晓.分峰计算结晶度的问题探讨[J].实验室研究与探索,2010,29(3):41-43.
[8] Xiao P,Gong Y J,Li D F,et al.In-situ SAXS study on pore structure change of PAN-based carbon fiber during graphitization[J].Microporous and Mesoporous Materials,2021,323:111201.
[9] Basiura-Cembala M,Erlacher K,Pedersen J S,et al.Phase densities and lamellar morphologies of semicrystalline polyethylenes via absolute small-angle X-ray scattering measurements[J].Journal of Applied Crystallogrphy,2015,48:1498-1506.
[10] Li X Y,Feng T,Gao X P,et al.WAXD/SAXS study and 2D fitting (SAXS) of the microstructural evolution of PAN-based carbon fibers during the pre-oxidation and carbonization process[J].New Carbon Materials,2017,32(2):130-137.
[11] 朱育平.小角X射线散射-理论、测试、计算及应用[M].北京:化学工业出版社,2009,165-170.
[12] 孟昭富.小角X射线散射理论及应用[M].长春:吉林科学出版社,1996,22-32.
[13] Rennhofer H,Loidl D,Puchegger S,et al.Structural development of PAN-based carbon fibers studied by in situ X-ray scattering at high temperatures under load[J].Carbon,2010,48(4):964-971.
[14] Ogale A A,Lin C,Anderson D P,et al.Orientation and dimensional changes in mesophase pitch-based carbon fibers[J].Carbon,2002,40(8):1309-1319.
[15] 华夏,史颖.聚丙烯腈纤维预氧化过程结构演变及与碳纤维结构比较[J].工程塑料应用,2021,49(6):125-129.
[16] 王彬,赵纯,张静.聚集态结构对聚丙烯腈纤维物理收缩的影响[J].北京化工大学学报:自然科学版,2012,39(1):48-52.
[17] Zhu C Z,Yu X L,Liu X F,et al.2D SAXS/WAXD analysis of PAN carbon fiber microstructure in organic/inorganic transformation[J].Chinese Journal of Polymer Science,2013,31(5):823-832.
[18] Liu J,Xiao S,Shen Z,et al.Study on the oxidative stabilization of polyacrylonitrile fibers by microwave heating[J].Polymer Degradation & Stability,2018,150:86-91.
[19] Wu G P,Li D H,Yang Y,et al.Carbon layer structures and thermal conductivity of graphitized carbon fibers[J].Journal of Materials Science,2012,47(6):2882.
[20] 周怡然,肖瑛阁,何烨,等.聚丙烯腈原丝预氧化过程中长周期结构的生成[J].材料导报,2017,31(S1):305-308.
基金资助
广东省重点领域研发计划(2019B010928001)
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