| 초록 |
In this study, vapor grown carbon nanofibers (VGCNFs)/poly(methyl methacrylate) (PMMA) composites containing two different grades (PR-19-HT and PR-24-HT) of VGCNFs manufactured by Applied Science Co. had been fabricated by melt blending. The amount of nanofibers used was varied with 1, 5, and 10 wt%. The nanofibers were well dispersed in the polymer matrix with no apparent damage or breakage. The dynamic mechanical behavior of the composites had been studied. As a result, the viscosity of the polymer was significantly increased by the incorporation of nanofibers particularly at high temperatures which was accompanied by an increase in the storage modulus. This result could be probably explained by the higher aspect ratio of the VGCNFs. Also VGCNFs were sonicated in the dimethylformamide (DMF) solution of poly(vinylidene fluoride) (PVDF) to form miscible blends and to improve the interfacial adhesion between VGCNFs and PMMA. The PVDF-covered VGCNFs were then melt-blended with PMMA. The presence of a small amount of PVDF (0.5 wt%) led to a significant improvement in the storage modulus of the composites at low temperatures that was almost twice as that of the composites without PVDF. However, a further increase in the PVDF content made a reduction of the storage modulus and the beneficial effect of PVDF was diminished at higher temperatures. |
