多胺型螯合纤维的结构表征和性能

STRUCTURE CHARACTERIZATION AND PROPERTIES OF POLYAMINE CHELATING FIBER

以聚丙烯腈纤维为原料,采用化学改性法,制备了多胺型螯合纤维.运用红外光谱分析,表征其化学结构、活性功能基,由IR图谱可知,—CN的特征峰几乎完全消失、1644 cm^-1处的—N—C N特征峰的出现,以及1600 cm^-1附近的—NH2弯曲振动峰、1580 cm^-1附近的—NH弯曲振动峰证实了N,N配位的功能基团——脒基及胺基的存在;采用示差扫描量热仪（DSC）分析改性前后纤维的热稳定性及其变化原因,因改性后纤维的结构改变较大,其热稳定性也相对降低;以扫描电镜仪（SEM）测试分析纤维制备过程中的微观形貌变化与其性能之间的关系;通过机械强度及直径测量,研究了改性前后纤维的机械性能变化,并对影响制备较高强度功能纤维的因素进行了分析;结合滴定曲线、交换容量,测定该纤维的化学稳定性及吸附性能.结果表明,该功能纤维表面及截面内均有较多的沟槽和微孔结构,具有较好的机械性能和化学稳定性,该纤维使用的最佳pH值范围是2.0-8.0,交换容量平均值为10 mmol.g^-1.

Polyamine chelating fiber was synthesized by chemical modification,with the raw material of polyacrylonitrile fiber.The chemical structure and active function groups were characterized by IR.From IR spectrogram,it was found that the nitrile group was almost completely disappeared and the new （—N—C）（N） characteristic absorption band was appeared at 1644 cm^-1.These results proved that polyamine chelating fiber was successfully synthesized,and the fiber has structural characteristics of N,N coordinative functional group——amidino and polyamine group,it can also be confirmed by the changes of bending vibration bands of —NH2 group and —NH group respectively near 1600 cm^-1 and 1580 cm^-1.Thermal stability was characterized by differential scanning calorimetry（DSC） and the change of thermal stability was analyzed.After amination reaction,the structure of the fiber was changed and heat stability of the fiber was relatively decreased.The micro configuration of fibers was characterized by SEM,the relationship between the micro configuration and adsorbability was explained.Mechanical capability of fibers was studied by mechanical strength and diameter measurements,and the influencing factors for preparing high intensity fiber was analyzed.Based on titration curve and exchange content,the chemical stability and quality of self-made chelating fiber were analyzed.The results indicate that the selfmade polyamine chelating fiber exhibits finer mechanical capability and chemical stability,having furrow and cellular structure in its surface and cross section.The average exchange capacity is 10 mmol·g^-1 and the fiber can be well used in the pH range of 2.0～8.0.