摘要
通过在线实时采集预氧化过程中聚丙烯腈纤维二维小角X射线散射(SAXS)花样,利用环化反应导致的电子云密度改变产生的SAXS谱图变化,研究亚微米结构在环化结构形成过程中的温度依赖性。根据所建立的环化及未环化的两相模型,在对散射信息中的微孔结构和长周期结构的叠加信号进行合理分离的基础上,研究了预氧纤维中长周期结构的生成和演变过程。结果表明,预氧化初期产生的环化相与非环化相呈现周期性结构堆砌,并随着温度的进一步升高逐渐趋于均一体系。同时结合相关函数分析方法,计算了长周期结构中环化相和非环化相厚度等结构参数,提出了预氧化程度的小角X射线散射定量表征的方法。
Small angle X-ray scattering(SAXS)was used to obtain the structural information of fibers in the submicro scale.According to the fundamentals of SAXS,the scattering signals came from the diversity of electron density in submicro structure,which were separated into the voids information and the long period structure by the mathematic analog computation method.In the present paper,the formation and evolution of long period structure of polyacrylonitrile(PAN)precursor during stabilization was investigated based on the established two-phase model by the in-situ temperature dependent measurement of SAXS.The results indicated that the cyclized phase and non-cyclized phase show a periodical aggregation structure when the temperature is up to 200℃.With the further increasing of temperature,it is gradually transformed to homogeneous system.Combining the correlation function analysis,the lamella thickness of both phases was calculated,and the detail parameters of the periodical structure were obtained,such as the length of the non-cyclized phase(d a),the length of cyclized phase(d c)and transition region(d t).And the length of long period structure remained unchanged.A new approach to estimate the degree of stabilization process was obtained,which provided a scientific foundation to perfect the characterizations about the transition from organic to inorganic in a submicron scale.
作者
周怡然
肖瑛阁
何烨
曹维宇
ZHOU Yiran;XIAO Yingge;HE Ye;CAO Weiyu(State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology, Beijing 100029;The Key Laboratory of Education Ministry on Carbon Fiber and Functional Polymer, Beijing University of Chemical Technology,Beijing 100029)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2017年第A01期305-308,共4页
Materials Reports
基金
国家科技支撑计划基金(2014BAE07B00)
关键词
聚丙烯腈原丝
预氧化
长周期结构
小角X射线散射
polyacrylonitrile precursor
stabilization
long period structure
small angle X-ray scattering
