New developments in polymer brush fabrication: concepts and physical properties of dynamic polymer brushes

Graphene oxide (GO)/carbon nanotube (CNT)/polypropylene (PP) nanocomposite materials were prepared by an epoxy resin (EP) using hand lay-up process. To enhance the mechanical properties and microstructure using 3-glycidyl ether oxy-propyl trimethoxysilane coupling agent in a one-step dipping coating process, the epoxy/polypropylene/carbon nanotube (EP-PP-CNT) functionalized composite with high bonding strength was created at the hierarchical structure, whereas reduced graphene oxides have been mingling within the epoxy resin. The solid-phase change structure was observed in an epoxy/polypropylene/graphene oxide/carbon nanotube (EP-PP-GO-CNT) functionalized composite, and the outer surface layer did not form the secondary dispersion. The tensile strength of EP-PP-GO-CNT functionalized samples was enhanced, reaching the yield point and elongation ratio of 38.1 MPa; moreover, epoxy/polypropylene/graphene oxide (EP-PP-GO) functionalized samples underwent ductility fractures. The average hardness value of EP (70%) blended with functionalized PP (10%), GO (10%) and CNT (10%) was highly present at 124 (Shore-D) in the outer surface layer. The three-point bending tests clearly indicated that the highest flexural modulus and flexural strength were observed in all composite materials. The microstructure was conducted on EP-PP-GO, EP-PP-CNT, and EP-PP-GO-CNT functionalized composites by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), respectively. The nanocomposites friction and wear were reduced due to the significant concentrations of functionalized GO, PP, and CNTs.