Fabrication of a mechanically tough and strong graphene oxide aerogel modified phenolic resin by balancing the trade-off between load transfer efficiency and chain segment mobility

In this work, a mechanically strong and tough novolac phenolic nanocomposites (GESNH) was successfully constructed by modulating its load transfer efficiency and chain segment mobility with reactive micro-sized graphene oxide aerogel (GES). DMA analysis reveals that the microstructure of GESNH can be divided into three regions including the bricks in mortar structure, the main phenolic networks and the constrained region, according to the significant difference in glass transition temperature (Tg) and fractional free volume (fg). Via controlling the volume fraction of three regions, load transfer efficiency and chain segment mobility of GESNH can be effectively tuned. Especially for 0.5%GESNH-5, flexural, tensile properties and fracture toughness are increased by 44.71%, 60.41% and 96.34%, compared with those of 0.5%GNH, where the volume fraction of the bricks in mortar structure as 0.086 and the constrained region as 0.169 facilitate the load transfer and the chain segment mobility, simultaneously.

Automated summary

By controlling the volume fraction of different regions, the load transfer efficiency and chain segment mobility of novolac phenolic nanocomposites can be effectively improved. In 0.5%GESNH-5, the volume fractions of the bricks in mortar structure and the constrained region promote load transfer and chain segment mobility, resulting in enhanced mechanical properties and toughness of the material.