采用相同工艺条件对均聚和共聚聚丙烯腈(PAN)基原丝进行梯度预氧化处理,通过有机元素分析、X射线衍射、傅里叶红外光谱、光学显微镜分析两种原丝在预氧化过程中微观结构的变化规律。详细探讨了共聚单体的引入对原丝和预氧丝结构的影响,以期为碳纤维实际生产提供一定的理论基础。研究结果表明,共聚单体的引入影响了PAN分子链的规整度,降低了原丝的结晶度,增大了晶间距和晶粒尺寸,使原丝的晶体结构在预氧化过程中更容易被破坏,可以使原丝的预氧化反应变得缓和,从而使更多的PAN分子链形成稳定的交联结构,同时可以减弱皮芯结构,改善纤维的匀质性。
The gradient pre-oxidation treatment of homopolymerized and copolymerized polyacrylonitrile-based precursor fibers were carried out under the same process conditions,and the variation rules of the microstructures of the two types of precursor fibers in pre-oxidation process were analyzed by organic elemental analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and optical microscope.The effects of the introduction of copolymer monomers on the structures of precursor fibers and pre-oxidized fibers were thoroughly explored with the aim of providing certain theoretical basis for the actual production of carbon fibers.The results showed that the introduction of copolymer monomers affected the regularity of PAN molecular chains,reduced the crystallinity of the precursor fibers,increased the intergranular spacing and grain size,so that the crystal structure of the precursor fibers was more likely to be destroyed during pre-oxidation process.It could make the pre-oxidation reaction of the precursor fibers become gentle,and more PAN molecular chains form a stable cross-linking structure,and at the same time,it could attenuate the skin-core structure and improve the homogeneous properties of the fibers.
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基金资助
吉林省碳纤维重大科技专项(YDZJ202203CGZH026);吉林市碳纤维及复合材料产业科技创新专项(20221003046)
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