Alhendal Abdullah, Shiju Jessy, Rashad Mohamed, Al-Sagheer Fakhreia, Ahmad Zahoor
Department of Chemistry, Kuwait University P. O. Box 5969 Safat 13060 Kuwait
RSC Adv. 2022 Sep 21;12(41):26753-26762. doi: 10.1039/d2ra04797g. eCollection 2022 Sep 16.
The synthesis and characterization of aramid composites reinforced with graphene platelets are reported. Hydroxy-functionalised graphene platelets were modified with two sol-gel binders (aminopropyl- or aminophenyl-trialkoxysilanes) and then chemically linked with aramid chains. The effect of the two sol-gel binders on the physiochemical and mechanical properties was evaluated. Chemical changes during the sol-gel reaction and subsequent amidation process in the nano-composite preparation were evaluated by the XPS and FTIR analyses. Thin films of these composites with different proportions of graphene were prepared. Morphology of the hybrids prepared was studied by the SEM technique. Properties of the composite films were studied by dynamical mechanical thermal (DMT) analysis to measure their glass transition temperature ( ) and storage modulus. These properties have been compared with previously reported values using pristine graphene (Gr) as a filler. The increase in thermal mechanical properties on addition of silanized graphene (SiGr) showed a large shift in the and more increase in storage modulus by chemically binding SiGr sheets on the aramid chains. Aminophenyl-trialkoxysilane was found to give better results due to the presence of phenyl groups which were more rigid than propyl groups present in aminopropyl-trialkoxysilane. The effect of chemical bonding and the possible π-π secondary bond interactions between the matrix and graphene platelets on the properties of the resulting hybrids are discussed.
本文报道了用石墨烯片增强的芳纶复合材料的合成与表征。用两种溶胶 - 凝胶粘合剂（氨丙基 - 或氨基苯基 - 三烷氧基硅烷）对羟基功能化的石墨烯片进行改性，然后使其与芳纶链化学连接。评估了这两种溶胶 - 凝胶粘合剂对物理化学和力学性能的影响。通过XPS和FTIR分析评估了纳米复合材料制备过程中溶胶 - 凝胶反应及随后的酰胺化过程中的化学变化。制备了具有不同石墨烯比例的这些复合材料的薄膜。通过SEM技术研究了所制备的杂化物的形态。通过动态机械热分析（DMT）研究了复合薄膜的性能，以测量其玻璃化转变温度（ ）和储能模量。将这些性能与先前报道的以原始石墨烯（Gr）作为填料的值进行了比较。添加硅烷化石墨烯（SiGr）后热机械性能的提高表明，通过将SiGr片化学结合到芳纶链上，玻璃化转变温度有很大的偏移，储能模量有更大的增加。由于氨基苯基 - 三烷氧基硅烷中存在比氨丙基 - 三烷氧基硅烷中的丙基更刚性的苯基，发现氨基苯基 - 三烷氧基硅烷能给出更好的结果。讨论了化学键合以及基体与石墨烯片之间可能的π - π二次键相互作用对所得杂化物性能的影响。
