纤维素纳米晶/环氧树脂复合材料的制备及性能研究

以过硫酸铵氧化微晶纤维素得到纤维素纳米晶(CNC),与二乙烯三胺在N,N-二甲基甲酰胺(DFM)中发生缩合接枝反应,制备胺化纤维素纳米晶(ACNC)。采用溶液共混法,分别将CNC和ACNC与环氧树脂复合得到纤维素纳米晶/环氧树脂复合膜,纤维素纳米晶不仅起到增强剂的作用,还起到固化交联剂的作用,进而改善环氧树脂的性能。利用万能力学试验机、动态热机械性能、环境扫描电子显微镜、热重分析等对复合材料的性能加以表征分析。结果证明,当CNC和ACNC的添加量均为0.1%时,环氧树脂复合膜的机械强度最大;纤维素纳米晶的加入不仅能够提高环氧树脂的力学性能,还能显著改善其柔韧性,ACNC对环氧树脂复合膜的增强作用高于CNC,CNC的增韧作用强于ACNC。

Synthesis and characterization of cellulose nanocrystal/epoxy resin composites

Cellulose nanocrystal(CNC)was prepared from microcrystalline cellulose by the oxidation of ammonium persulfate,which was grafted with diethylene triamine in N,n-dimethyl formamide(DFM)to prepare aminated cellulose nanocrystal(ACNC).The epoxy resin composites were obtained by compounding CNC and ACNC solution with epoxy resin,respectively.CNC and ACNC acted not only as reinforcing agents,but also as curing crosslinking agents in epoxy resin composites.Properties of the composites were characterized by universal mechanical testing machine,dynamic thermomechanical analysis,environmental scanning electron microscope and thermogravimetric analysis.The results show that when the addition amount of CNC and ACNC was 0.1%,the mechanical strength of the epoxy resin composite was the highest.CNC and ACNC could not only improve the mechanical properties of epoxy resin,but also significantly improve its flexibility.The reinforcing effect of ACNC on epoxy resin was higher than that of CNC whereas toughening effect of CNC on epoxy resin was stronger than that of ACNC.