PE-LD/硅烷偶联剂改性石墨烯复合薄膜的制备及性能表征

Preparation and Characterization of Low-density Polyethylene/Functionalized Graphene Nanocomposite Films

将硅烷偶联剂KH-560接枝到氧化石墨烯上制得KH-560改性氧化石墨烯(KGO),通过水合肼还原得到KH-560改性石墨烯(KG),最后将KG和石墨烯(G)分别与低密度聚乙烯(PE-LD)熔融共混、中空吹塑成PE-LD/KG复合薄膜和PE-LD/G复合薄膜。对样品的结构、形貌、光学性能、阻透性能、热性能和力学性能等进行表征。结果表明,KH-560成功接枝到KG上;KG无序度增加,KG的层间距比G增加约80%;KG在PE-LD中分散均匀,团聚较少;G对复合薄膜的光学性能和阻透性能的增强效果优于KG;而KG对复合薄膜的热性能和力学性能的改善明显优于G;当KG的含量为0.5%(质量分数,下同)时,PE-LD/KG复合薄膜的结晶度和弹性模量分别比纯PE-LD薄膜提高了8.4%和63.9%。

Graphene oxide was modified withγ-(2,3-epoxypropoxy)propytrimethoxysilane(KH-560)via a surface grafting method,followed by a reduction reaction with hydrazine hydrate to form functionalized graphene.The low-density polyethylene(PE-LD)-based nanocomposite films were prepared by melt blending with functionalized graphene as well as the pristine one,followed by hollow blow molding,and their structures,morphologies,optical performance,and thermal and mechanical properties were characterized.The results indicated that the silane coupling agent,KH-560,was successfully grafted onto graphene.Compared to pristine graphene,the functionalized graphene exhibited an increase in disorder,and its interlayer space increased by approximately 80%,which resulted in a better distribution in PE-LD matrix and a decrease in aggregation.Moreover,the thermal stability and mechanical properties of nanocomposite films were improved by functionalized graphene more significantly in comparison with pristine graphene.However,pristine graphene could enhance the optical and barrier properties more effectively.Compared to pure PE-LD films,the nanocomposite film containing 0.5 wt%of functionalized graphene presented an increase in crystallinity degree by 8.4%and in Youngs modulus by 63.9%.