聚硅氮烷的干法纺丝及纤维的紫外辐照交联研究

Dry Spinning of Polysilazane and Ultraviolet Irradiation Cross-Linking of Fibers

将不同质量的聚硅氮烷(PSZ)先驱体溶于二甲苯中,配制成不同浓度的纺丝液,并通过干法纺丝、紫外辐照交联法以及1 100℃高温裂解将PSZ纺丝液转化为硅碳氮(氧)(SiCN(O))纤维。采用旋转流变仪、FTIR、SEM、XPS和TG等手段研究了PSZ纺丝液的流变性能和PSZ纤维的紫外辐照交联过程,并对辐照前后的PSZ纤维及SiCN(O)纤维的组成、结构和性能进行了表征。结果表明,质量分数为87%的PSZ纺丝液在室温下存在切力变稀的行为,属于假塑性流体,具有优异的干法纺丝性能;PSZ纤维在波长为185 nm的紫外光下辐照7 h后,其陶瓷产率较原纤维提升了30.8%。本研究对于PSZ新的纺丝工艺和PSZ纤维的不熔化处理具有一定的探索意义。

The precursors of polysilazane(PSZ) with different weights were dissolved in xylene to obtain the spinning solution with different concentration.PSZ spinning solution was converted to SiCN(O) fibers by dry spinning,ultraviolet(UV) irradiation cross-linking,and pyrolysis at 1 100 ℃.The rheological property of PSZ spinning solution and the UV irradiation cross-linking process of PSZ fibers were investigated by rotational rheometer,FTIR,XPS,SEM and TG.The composition,structure and properties of PSZ fibers and SiCN(O) fibers before and after irradiation were also characterized.The results show that the PSZ spinning solution with the mass fraction of 87% has shear thinning behavior at room temperature,which belongs to the pseudoplastic fluid and has excellent dry spinning performance.The ceramic yield of PSZ fibers increases by 30.8% compared with the green fibers after 7 h cross-linking under UV irradiation with wavelength of 185 nm.This research has certain exploration significance for the new spinning process of PSZ and the curing treatment of PSZ fibers.