Rubber Technology Centre, Indian Institute of Technology, Kharagpur, 721302 India.
Nanoscale Res Lett. 2009 Mar 21;4(7):655-64. doi: 10.1007/s11671-009-9296-8.
A series of ethylene vinyl acetate (EVA) nanocomposites using four kinds of EVA with 40, 50, 60, and 70 wt% vinyl acetate (VA) contents and three different carbon-based nanofillers-expanded graphite (EG), multi-walled carbon nanotube (MWCNT), and carbon nanofiber (CNF) have been prepared via solution blending. The influence of the matrix polarity and the nature of nanofillers on the morphology and properties of EVA nanocomposites have been investigated. It is observed that the sample with lowest vinyl acetate content exhibits highest mechanical properties. However, the enhancement in mechanical properties with the incorporation of various nanofillers is the highest for EVA with high VA content. This trend has been followed in both dynamic mechanical properties and thermal conductivity of the nanocomposites. EVA copolymer undergoes a transition from partial to complete amorphousness between 40 and 50 wt% VA content, and this changes the dispersion of the nanofillers. The high VA-containing polymers show more affinity toward fillers due to the large free volume available and allow easy dispersion of nanofillers in the amorphous rubbery phase, as confirmed from the morphological studies. The thermal stability of the nanocomposites is also influenced by the type of nanofiller.
采用乙烯-醋酸乙烯酯（EVA）共聚物（VA 含量分别为 40wt%、50wt%、60wt%和 70wt%）和三种不同的碳基纳米填料（膨胀石墨（EG）、多壁碳纳米管（MWCNT）和碳纳米纤维（CNF））通过溶液共混制备了一系列 EVA 纳米复合材料。研究了基体极性和纳米填料的性质对 EVA 纳米复合材料的形态和性能的影响。结果表明，VA 含量最低的样品具有最高的力学性能。然而，对于高 VA 含量的 EVA，各种纳米填料的加入对力学性能的增强作用最高。这一趋势在纳米复合材料的动态力学性能和热导率中都得到了体现。EVA 共聚物在 40wt%到 50wt%VA 含量之间经历了从部分无定形到完全无定形的转变，这改变了纳米填料的分散状态。由于高 VA 含量的聚合物中存在大量的自由体积，它们对填料具有更大的亲和力，并允许纳米填料在无定形橡胶相中容易分散，这从形态学研究中得到了证实。纳米复合材料的热稳定性也受到纳米填料类型的影响。
