炭化气场压力对PAN基碳纤维聚集态结构和力学性能的关联性研究  

Effect of carbonization atmosphere pressure on the aggregation structure and mechanical property of polyacrylonitrile based carbon fiber

作　　者：刘杰[1] 牛鹏飞[1] 薛岩[1] 梁节英[1] 

机构地区：[1]北京化工大学碳纤维及功能高分子教育部重点实验室,北京100029

出　　处：《复合材料学报》2013年第S1期7-14,共8页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51073011)

摘　　要：采用小角X射线散射(SAXS),广角X射线衍射(WAXD),气相色谱(GC),扫描电子显微镜(SEM)等表征手段,定量探讨了炭化气场压力对PAN基碳纤维聚集态结构及其力学性能的影响。结果表明:PAN基碳纤维密度及其晶区含量与炭化气场压力(P0)具有显著关联性,三者同步提升,趋势明显。SAXS和WAXD研究分析表明:气固相反应体系内的热量传递和释放对PAN基碳纤维微晶结构和微孔结构的形成影响显著,炭化气场微正压实现热量的有效传递的及时释放,有利于小晶粒的形成,并对孔隙的形成具有抑制作用。保持气场压力(P0)为30Pa,所得PAN基碳纤维的微孔尺寸(4.36nm)和微晶尺寸(1.34nm)最小,孔隙率(14.4%)最低,此时拉伸强度(3.96GPa)最高,较常压和高压条件下制备的PAN基碳纤维最高提升了15.8%。The effect of the carbonization atmosphere pressure on the aggregation structure and mechanical property of polyacrylonitrile(PAN)based carbon fibers was quantitatively investigated by means of small angle X-ray scattering(SAXS),wide angle X-ray diffraction(WAXD),gas chromatography(GC)and scanning electron microscope(SEM).The results indicate that the density and crystal content of PAN-based carbon fibers significantly depend on the carbonization atmosphere pressure(P0),which exhibits that they are increased synchronously and obviously.The effect of the heat transfer and release on the formation of microcrystalline structure and microvoid structure is remarkable.The slight positive pressure of carbonization atmosphere is favorable for the formation of small crystalline grain and decrease of pore because of heat effective transfer and release in time.When P0 is 30Pa,the microcrystalline structure(1.34nm)and microvoid structure(4.36nm)of PAN-based carbon fibers are both the smallest and the porosity(14.4%)is the lowest;meanwhile,the PAN-based carbon fibers possess the optimum tensile strength of 3.96GPa which is 15.8% higher than other carbon fibers obtained under normal pressure and high pressure.

关 键 词：聚丙烯腈 气场压力 微孔结构 微晶结构 碳纤维 

分 类 号：TQ342.742[化学工程—化纤工业]