摘要:
采用多聚磷酸(PPA)/P2O5弱酸体系, 通过傅克反应(Friedel-Crafts reaction)对多壁碳纳米管(MWCNTs)进行功能化改性, 加入己内酰胺后采用原位聚合法制备功能化碳纳米管(F-MWCNTs)/尼龙6(PA6)复合材料, 并熔融纺丝制备复合纤维。通过TEM、TG、DSC、SEM及力学性能测试对复合纤维进行表征。结果表明: 在MWCNTs表面成功地接枝了氨基, F-MWCNTs均匀地分散在PA6基体中, 没有发生团聚现象, 并且与基体具有很好的界面作用; F-MWCNTs的加入, 对复合纤维的熔融温度和结晶度影响不大, 结晶温度有所提高, 并明显提高了复合纤维的热稳定性; 随着F-MWCNTs的加入, 复合纤维的拉伸断裂强度和杨氏模量增加, 当F-MWCNTs质量分数为0.5%时, 拉伸断裂强度和杨氏模量达到最大, 比纯PA6纤维分别提高了45%和208%。
Abstract:
Multi-walled carbon nanotubes(MWCNTs) were functionalized with 4-substituted benzoic acid via direct Friedel-Crafts acylation in a mild reaction medium of polyphosphoric acid(PPA)/pentoxide(P2O5). Functionalized multi-walled carbon nanotubes (F-MWCNTs)/polyamide 6(PA6) composite was prepared via in situ polymerization and the dried powders were melt-spun into fibers. The fibers were characterized using TEM, TG, DSC, SEM. MWCNTs inherently have functional groups on their surfaces as a result of the reaction. F-MWCNTs are homogeneously dispersed in PA6 matrix without any aggregation. The incorporation of F-MWCNTs into PA6 has no obvious effect on the melting point and the crystallinity of PA6, except increasing the crystallization temperature. With the content of F-MWCNTs increasing, thermal stability of the composite fibers is improved significantly. The tensile strength and Young’s modulus of the fibers are significantly improved with increasing the content of F-MWCNTs. The tensile strength and Young’s modulus of the fibers reach a maximum when the mass fraction of F-MWCNTs is 0.5%, which are improved by 45% and 208% respectively than PA6 fibers.
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