热处理气氛对制备氧化锆连续纤维的影响

Effect of Heat-treatment Atmosphere on Preparation of Continuous Zirconia Fibers

以氧氯化锆、乙酰丙酮等为原料合成聚乙酰丙酮合锆纺丝液,经干法纺丝和水蒸气气氛热处理制备氧化锆连续纤维。通过DSC-TGA、FT-IR、GC-MS、SEM等手段,研究了纤维在空气和水蒸气气氛热处理中的热解转变机制。结果表明,在空气气氛热处理过程中,聚乙酰丙酮合锆前驱体纤维中所含有机物以脱氢碳化和碳氧化方式被去除,产生的应力使氧化锆纤维结构出现裂纹,纤维强度低;而在水蒸气气氛热处理过程中,有机物在水蒸气水解作用下直接以分子整体挥发的方式被去除,所得氧化锆纤维结构致密均匀、强度高。

Continuous zirconia fiber was prepared by using zirconium oxychloride and acetyl acetone to synthesize the spinning solution of polyacetylacetonatozirconium, followed by dry spinning and heat treatment under steam atmosphere. DSC-TGA, FT-IR, CA2-MS and SEM were used to study the fibers＇ transformation mechanism during heat treatment under air and steam atmosphere. Results show that the organics within the precursor fibers are removed by carbonization and carbon-combustion mode when the fibers are heat-treated under air atmosphere, resulting in the structural stress and micro-cracks in zirconia fibers＇ structure. As a result, the obtained zirconia fibers have low strength. However, when the precursor fibers are heat-treated under steam atmosphere, the organics within fiber are removed directly with molecular form by the hydrolysis action of steam, and the obtained zirconia fibers have compact, uniform microstructure with high strength.