PMMA/MWNT纳米复合材料原位合成及性能

In-situ Synthesis and Characterizaiton of PMMA/MWNT Nanocomposites

利用相转移反应在羧基化碳纳米管的表面引入具有反应活性的苯乙烯双键,利用双键的反应性,与MMA单体进行自由基原位聚合反应,得到PMMA修饰的碳纳米管.这种聚合物修饰的碳纳米管可以在对PMMA有溶解效力的有机溶剂中溶解,利用FTIR,TGA,TEM等对这种聚合物修饰的碳纳米管的结构、修饰效率以及在有机溶剂中的溶解和分散性能进行了表征.结果表明,通过这种方法可以实现高分子链对碳纳米管表面有效修饰.利用这种原位聚合反应,不进行均聚物的分离可以一步得到聚合物基纳米复合材料.作为比较,相同量未经任何修饰的碳纳米管用相同的方法,在相同条件下也制备了PMMA纳米复合材料,并将两个样品中碳纳米管的分散状态用扫描电镜(SEM)进行了观察,同时对其力学性能与相同条件下得到的PMMA均聚物进行了比较.

Firstly,reactive styrene monomers were bonded onto the surface of carbon nanotubes through phase transfer reaction.Utilizing the reactivity of the double bond,MMA monomers can react with the modified double bonds,forming PMMA long chain polymer on the surface of MWNT.The structure and properties of the obtained PMMA-modified MWNT was characterized by a series of methods.FTIR and TGA results show successful modification by PMMA,TEM shows that the modified MWNT can resolve in the organic solvents singly.Using this method,PMMA/MWNT nanocomposites could be synthesis by in-situ polymerization,samely,pristine MWNT was used to compare the influnce of modification on the dispersion and the properties of the nanocomposites,SEM showed that the styrene modified MWNT dispersed uniformly in the base of nanocomposite,no obvious aggregation phenomenon occurred,however,for the pristine MWNT,there was obviously accumulating behavior could be observed.Mechanical properties characterization of the two kinds of nanocomposites compared to the pure PMMA show that the surface modification of the MWNT has important influence on the ultimate properties of the nanocomposites,for the nanocomposite containing the modified MWNT,the mechanical properties were improved compared to the pure PMMA,but for the composite with pristine MWNT,the properties decreased compared to the pure PMMA.