纤维素纳米晶修饰氧化石墨烯对环氧树脂固化动力学的影响

Effect of Cellulose Nanocrystalline Modification of Graphene Oxide on Curing Kinetics of Epoxy Resin

利用纤维素纳米晶(CNC)改性氧化石墨烯(GO)制备了纳米填料GC,并制备了环氧树脂(EP)/GC复合纳米材料,通过差示扫描量热法(DSC)研究了GC对EP纳米复合材料固化动力学的影响。采用Kissinger和Ozawa方法得到了EP/GC复合纳米材料的相关固化动力学参数。结果表明,相比于单一纳米填料GO或CNC,复合纳米填料GC能够更有效地降低EP的固化特征温度(固化起始温度、固化峰值温度和固化终止温度),促使固化过程在更低的温度下进行。在相同的固化温度下,EP/GC材料的固化程度更高;在固化初期,EP/GC材料的固化速率更快,且可更快地达到固化速率峰值。通过Kissinger方法计算,相比于纯EP,EP/GC材料的表观活化能(Ea)从52687 J/mol降低至45234 J/mol,降低了14%;通过Ozawa方法计算,在相同的转化率下,EP/GC材料的Ea更低。复合纳米填料GC对EP体系固化过程的促进作用更为明显,对固化反应具有更为显著的催化作用。

Nanofillers GC were prepared by modifying graphene oxide(GO)with cellulose nanocrystals(CNC),and epoxy resin(EP)/GC composite nanomaterials were prepared.The effects of GC on the curing kinetics of EP-based composites were studied through differential scanning calorimetry(DSC)testing.The relevant curing kinetics parameters of EP/GC composite nanomaterials were obtained via Kissinger and Ozawa methods.The results indicate that compared with one single nanofiller GO or CNC,composite nano filler GC can more effectively reduce the curing characteristic temperatures(curing initial temperature,curing peak temperature and curing terminal temperature)of EP,promoting the curing process to proceed at lower temperatures.At the same curing temperature,the curing degree of EP/GC material is higher.In the early stage of curing,the curing rate of EP/GC material is faster and the peak curing rate can be reached faster.According to the Kissinger method,compared to pure EP,the Ea of EP/GC material decreases by 14%from 52687 J/mol to 45234 J/mol.According to the Ozawa method,compared to pure EP,the apparent Ea of EP/GC material is lower at the same conversion rate.The composite nanofiller GC has a more significant promoting effect on the curing process of the EP system and has a more significant catalytic effect on the curing reaction.