湿化学法合成先驱体制备氮化硼纤维的研究

以硼酸和三聚氰胺为原料,采用湿化学法合成先驱体,在氮气气氛中制备出氮化硼(BN)纤维。用中和滴定法、红外吸收光谱(IR)、X射线衍射(XRD)、扫描电镜(SEM)对合成的先驱体及制得的BN纤维的氮含量、形貌及结构进行分析。结果表明合成温度1,700℃,保温时间3 h,氮气流量2 L/min时制得的BN纤维的氮含量为53.46%,达到理论值的95%。先驱体分子中存在B—N、N—H、C—O—C、—(B—N)—结构单元。用扫描电镜观察制得的BN纤维直径为2~10 靘,长径比为40~50。

Research on Synthesis of BN Fibers with Precursors Prepared by Wet Chemical Method

A process was developed for making boron nitride (BN) fibers with the precursors prepared by wet chemical method, and with boric acid (H3BO3) and melamine (C3N6H6) as starting materials. The precursors and products synthesized wherefrom were analyzed by neutralization titration, IR, XRD and SEM. The results show that N content of BN fibers reach 53.46% when reaction temperature is 1 700℃, soaking time 3 hours and nitrogen flow 2.0 L/min. The precursors consist of B—N, N—H, C—O—C, —(B—N)—. The diameter of BN fiber is from 2 mm to 10 mm and length/diameter ratio from 30 to 40.