论文部分内容阅读
通过对聚丙烯腈(PAN)原丝到碳纤维制备过程各阶段纤维质量和组成的变化的分析,研究了预氧化过程、低温碳化过程和高温碳化过程C、N、H和O的演变规律,结果表明:预氧化过程中伴随着O的结合,纤维中部分N、C和H发生脱除,N和H的脱除量随着O的增加量线性增加,其中1/4左右的H在此阶段脱除;低温碳化阶段是纤维大量脱除非碳成分的过程,N、H、O的脱除量占碳纤维制备过程总脱除量的50%左右,低温碳化也是C损失最大的一个阶段,占C总损失量的60%左右;高温碳化过程是纤维中N、H和O进一步脱除的过程,经过1250℃的高温碳化后,原来原丝中的N和H原子剩余量分别为13.7%和6.5%,O在此阶段几乎全部脱除,并且N和H的脱除量随高温碳化温度的提高而增加。通过对各阶段脱除原子数的相对含量的进一步分析,推测了预氧化过程PAN纤维的环化机理以及碳化阶段非碳成分的脱除形式。
Through the analysis of the changes of fiber quality and composition during the process of polyacrylonitrile (PAN) precursor to carbon fiber preparation, the evolution of preoxidation process, low temperature carbonization process and high temperature carbonization process of C, N, H and O were studied. The results It is indicated that with the combination of O in the pre-oxidation process, part of N, C and H in the fiber are removed, and the removal amounts of N and H increase linearly with the increase of O, of which about 1/4 of H are in this stage Removal; low temperature carbonization stage is a large number of non-carbon fiber removal process, N, H, O removal of carbon fibers accounted for about 50% of the total removal of the process, low-temperature carbonization is the C loss of a stage, accounting for C 60% of the total loss. The high-temperature carbonization is the process of further removal of N, H and O in the fiber. After the high-temperature carbonization at 1250 ℃, the remaining N and H atoms in the original filament are 13.7% and 6.5% %, O is almost completely removed at this stage, and the amount of N and H removal increases with the increase of temperature carbonization temperature. Through the further analysis of the relative content of the number of atoms removed in each stage, the circularization mechanism of the PAN fibers during the pre-oxidation process and the removal form of the non-carbon components in the carbonization stage are presumed.