碳纤维/MC尼龙6原位复合材料的制备与表征

Synthesis and Characterization of CF/MC Nylon 6 In-Situ Composites

提出一种表面接枝尼龙6的碳纤维/MC尼龙6原位复合材料的制备方法并加以表征.通过对碳纤维表面的-COOH和-OH官能团进行异氰酸酯化并用己内酰胺稳定化,再将碳纤维加入到己内酰胺单体融体中,采用阴离子聚合方法制得表面接枝尼龙6的碳纤维/MC尼龙6原位复合材料.红外和热重分析都表明,碳纤维表面已接枝上异氰酸酯和己内酰胺.热重分析计算得接枝率为2.69%.用DSC研究复合材料的非等温结晶和熔融行为,结果表明碳纤维对基体尼龙6具有异相成核作用,并且结晶速度提高;碳纤维表面接枝的尼龙6在结晶前期对晶体生长有诱导和促进作用,而在结晶后期有位阻作用,使晶体的粒度变小,结晶的完善程度降低.拉伸实验表明,碳纤维/MC尼龙6原位复合材料的拉伸强度与MC尼龙6相近.

A new method of synthesizing carbon fiber （CF, whose surface is grafted by nylon 6）/MC nylon 6 in-situ composites is proposed and the composites are characterized. First, functional groups （-COOH and -OH ） on carbon fiber surface are translated into CF-NCO and stabilized by caprolactam. Then carbon fiber is added into caprolactam monomer and CF/MC nylon 6 in-situ composites can be obtained by means of anionic polymerization. Both IR analysis and TG analysis shows that carbon fiber surface has been grafted by isocyanic ester and caprolactam. TG results shows the grafting degree was 2.69%. Nonisothermal crystallization behaviors and melting characteristics are investigated by DSC. The resuits shows that CF plays the role of heterogeneous nucleating agent, which enhances crystallization rate of MC nylon 6. Grafted CF in CF/MC nylon 6 can induce and promote crystallization in the first stage, then hold back crystallization in later stage, making crystal particles get little and crystallization uncompleted. Tensile strength test results indicate CF/ MC nylon 6 and MC nylon 6 have similar tensile strength.