Few if any reports exist that elucidate the phenomena that take place in the microwave-assist polymerization (MAP) of heterogeneous multi-component systems to form polymer nanohybrid composites. We elucidate the four distinct steps that take place during the in-situ MAP of Nylon-6 from epsilon-caprolactam and 6-aminocaproic in the presence of graphite oxide (GrO), which results in the formation of a reduced graphene oxide Nylon-6 nanohybrid in a one-step synthesis; exfoliation, reduction take place in <60 s; polymerization occurs after 60 s; hybridization during both periods. An increase in molecular weight and conversion of non-grafted Nylon-6 during hybridization takes place unlike in conventional in-situ polymerizations of Nylon-6/GrO where reduction of the MW is observed. It is also shown for the first time that the crystallization of grafted Nylon-6 in the hybrid exists in both a and y phases. The grafted molecules represent 50 wt % of the hybrid. (C) 2018 Elsevier Ltd. All rights reserved.