Understanding the structural changes, interfacial mechanisms, and mechanical properties of polymer/MWCNT nanocomposites after microwave treatment

Abstract The use of microwave radiation for the post‐processing treatment of engineering polymers is a recent trend not seen by many. In the case of polymers, their crystalline nature is a significant factor in optimizing the treatment time for maximum improvement in mechanical properties. With the advent of nanomaterials, the aim of the present work is to explore the possibility of post‐processing microwave treatment on the structure and property relationships in MWCNT‐reinforced polymer matrices. The microwave‐activated nucleating tendency of MWCNTs was found to be promoting molecular chain rearrangement in poly‐amide (PA) and poly‐butylene‐terephthalate (PBT) nanocomposites. This considerably improved the mechanical characteristics of the composites by facilitating the rearrangement of the crystalline segments of the polymer matrix. The wear performance of PA nanocomposite increased by 30%, while the elongation of PBT nanocomposite increased by 93%, after a treatment of only 15–20 s. However, comparing with previous studies, it was found that, similar to virgin polymers, the treatment time needed for maximum improvement in polymer/MWCNT nanocomposites is hugely dependent on polymer matrix crystallinity as well. A detailed analysis of the microwave‐treated nanocomposites' structure and mechanical properties illustrates the post‐processing microwave treatment as a time‐efficient, cost‐effective, and environmentally friendly technique. Highlights Direct use of microwave radiation to heat the finished polymeric component. Microwave treatment brings about structural changes resulting in enhanced properties. Instantaneous heating is a key reason for the systematic arrangement of polymeric chains. Microwave‐activated nucleating tendency of MWCNTs also promotes chain arrangement. Properties increase as high as 30% wear rate and 93% elongation.