纺丝液合成因素对木材液化物炭纤维原丝性能的影响

Effect of spinning solution factors on properties of carbon fiber precursors prepared with liquefied wood

利用木材苯酚液化物合成纺丝液,熔融纺丝制成新的炭纤维原丝,研究了纺丝液合成因素对原丝性能的影响。试验结果表明:增加合成纺丝液时液化原料中的苯酚/木材比(液固比),则原丝的力学性能提高明显,其中液固比由3增加至4时,原丝拉伸强度增加了近9倍;合成剂用量的增加却导致原丝力学性能的降低,当合成剂用量为6%时,原丝的拉伸强度和拉伸模量降幅较明显,而断裂伸长率的最大降幅却出现在合成剂用量为4%时;原丝的拉伸强度和拉伸模量随合成温度的升高而增加,但增幅较小,断裂伸长率随合成温度的升高却呈下降趋势,且从110℃升高到115℃时断裂伸长率降幅较大;原丝的力学性能随合成纺丝液升温时间的增加而先升高后降低,升温时间为40 min时制备的炭纤维原丝的力学性能最优。

A new carbon fiber precursor was prepared from liquefied wood in phenol, which was used to synthesize the spinning solution by melt-spinning. The effect factors of spinning solution on the properties of carbon fiber pre- cursors were studied. The results show that the tensile strength/modulus and the elongation at break of carbon fiber precursors increase obviously with increasing the phenol/wood ratio in the wood liquefaction. Moreover, the tensile strength increases nearly 9 times when the phenol/wood ratio increases from 3 to 4. The mechanical properties of carbon fiber precursors drop with increasing the synthetics content. The peak decreasing amplitude of the tensile strength and modulus of precursors occurs at adding 6% synthetics content, but the elongation at break reaches the maximum at 4% synthetics content. The tensile strength and modulus have no obvious increase with increasing the synthesis temperature, while the elongation at break decreases and shows obvious decreasing amplitude from 110℃ to 115 ℃. The mechanical properties of precursors are improved with increasing the temperature rise time and then drop, and carbon fiber precursors show optimum mechanical properties at the temperature rise time of 40 min.