The Side‐Chain Liquid Crystalline Epoxy Polymer Grafted Nanoparticles for the Thermal and Mechanical Enhancement of Epoxy Nanocomposites

Abstract

In order to enhance the dispersion and the interface in epoxy nanocomposites filled nanoparticles, a novel side‐chain liquid crystalline epoxy polymer (SLCEP) was synthesized. The SLCEP grafted to alumina (Al2O3) surfaces via the carboxyl group for dispersing nanoparticles, bonded covalently with the epoxy matrix by the epoxy group for interface improvement and maintained good liquid crystal properties by the mesogenic unit. The dispersity of Al2O3 in Al2O3‐SLCEP and epoxy nanocomposites were studied by Fourier transform infrared imaging system and field emission scanning electron microscopy. The interface of epoxy nanocomposites was researched by observing the fracture morphology. By preventing the agglomeration of Al2O3 and strengthening its interfacial bonding with the matrix, the glass transition temperature and thermal stability of Al2O3‐SLCEP/epoxy nanocomposites were improved distinctly, and Al2O3‐SLCEP/epoxy nanocomposites were much superior to neat epoxy in mechanical properties. The excellent performance of SLCEP modified nanoparticles in epoxy demonstrates that is an effective general approach for nanoparticle/polymer.

Improving the Fracture Toughness and Strength of Epoxy Resin Using NH2‐silica‐C8H17 Janus Nanosheets

“…The formation of cavities or voids is a likely result of the debonded nanosheets, which are pulled out completely and partially from the fracture surface, and situated on its either side during fracture. In general, the rougher surface and crack deflections lead to a prominent increase in the total fracture surface area, [53] and meanwhile, the particle debonding and the subsequent plastic void growth can be considered as the main contributor to the increased toughness [54,55] . In addition, the crack pinning process could not be excluded from our work, because the lateral size of NH 2 ‐silica‐C 8 H 17 nanosheets is at the scale of a few microns, which would be larger than or at least comparable to the crack‐opening displacement [54,56] …”

Effect of composite to aluminum single lap joints reinforced with graphene doped nylon 6.6 nanofibers

“…These changes were observed both due to the changes in the chain structure and the difference in the melting temperature of materials such as graphene and N6.6 polymer that were trapped between the chains but did not make any chemical bonds. 32,33 Adhesive shear strength of single lap joints…”