水辅混炼挤出聚苯乙烯/氧化石墨烯纳米复合材料的微观结构及流变与热性能

Microstructure,Rheological Behavior and Thermal Stability of Polystyrene/Grapheme Oxide Nanocomposites Prepared by Water-assisted Mixing Extrusion

采用自主设计的水辅混炼挤出设备,制备3种氧化石墨烯(GO)含量(0.1%、0.3%、0.5%,质量分数,下同)的聚苯乙烯(PS)/GO纳米复合材料,观察样品的微观结构,测试其流变性能和热性能。结果表明,GO被较好剥离且呈网状较均匀地分散在PS基体中,这主要归因于螺杆混炼流场不断细化PS熔体中的GO悬浮液以及水对熔体的塑化和溶胀效应促进PS分子链插层进入GO片层之间的共同作用;低频区PS/GO样品的储能模量、复数黏度和松弛时间均比纯PS样品的高,这是因为较均匀分散的网状GO片与PS之间形成较强的分子间作用力,降低了PS分子链的活动性;PS/GO样品的热稳定性比纯PS样品的高,这归因于GO片在PS基体中呈网状分布和GO表面存在π键。

Three polystyrene/graphene oxide （PS/GO） nanocomposites （GO contents 0. 1 wt%, 0. 3 wt%, and 0. 5 wt%） were prepared using home-designed water-assisted-mixing extrusion equipment. Microstructure, rheological behavior, and thermal stability of the nanocomposite samples were investigated. It demonstrated that GO was well exfoliatedand dispersed in network structure in PS matrix. This was attributed to the fact that PS chain was easy to intercalate and exfoliate GO layers. PS/GO samples exhibited higher elastic moduli, complex viscosities, and relaxation times at low frequencies as compared with neat PS, which was because of the stronger intermolecular force between well dispersed GO layers in network structure and PS. PS/GO samples exhibited higher thermal stability than neat PS sample, which was due to the GO network in PS matrix and π bond at GO surface.