Melt rheology and thermomechanical behavior of poly(methyl methacrylate)/reduced graphene oxide nanocomposites

Abstract

Thermomechanical and rheological behavior of poly(methyl methacrylate) (PMMA)/reduced graphene oxide (RGO) nanocomposites prepared via in situ polymerization using sheet casting method was investigated. Scanning electron microscope and transmission electron microscope were used to study the microstructure of nanocomposites in terms of dispersion of RGO and polymer-RGO interaction. The thermomechanical properties were investigated using dynamic mechanical analyzer, and it was found that the incorporation of RGO sheets into PMMA matrix resulted in an increase in both storage modulus and glass transition temperature (T g ) as compared with neat PMMA. Storage modulus showed an increase of 40% and 46% at a loading of 0.5 and 1.0 wt% RGO, respectively. The glass transition temperature showed an increase of 20°C (104°C for neat PMMA) at RGO loading of 2.0 wt% (124°C for sample PMMA-2.0). The complex viscosity and moduli (storage and loss) as a function of angular frequency also showed an increase with increasing amount of RGO. A significant increase in melt viscosity of PMMA observed in case of sample having 0.5 wt% RGO (sample PMMA-0.5) could be due to the formation of interconnected network of RGO in PMMA matrix and can be considered as rheological percolation threshold. A drop in the crossover frequency was registered with increase of RGO loading that does not directly correlate with the percolation threshold concentration, representing an increase in solid-like behavior. Secondly, the complex viscosity did not change with RGO loading at higher frequency, which showed that the short-range PMMA relaxations were unaffected by RGO.

Characterization of melt-blended graphene – poly(ether ether ketone) nanocomposite

“…Previous studies reported large increases in T g with small additions of graphene to a variety of polymers [36,38,39] and speculate that this large shift is due to chain interaction on the surface of graphene with attached functional groups. [36]…”

“…Similar increases have been reported with other graphene-polymer composites and other polymer nanocomposites. [36,37] Furthermore, T g increase from 152 °C to 166 °C for PEEK and 5Gn-PEEK, respectively, as measured by the loss modulus (G") peak maximum.…”

Influence of reduced graphene oxide on flow behaviour, glass transition temperature and secondary crystallinity of plasticized poly(vinyl chloride)

“…The effect of reduced graphene oxide (RGO) on melt rheological properties of poly(methyl methacrylate) (PMMA) were analyzed. 12 They have found that moduli and viscosity of PMMA/RGO nanocomposites increased with increase in RGO loading, and a decrease in viscosity was observed with increasing frequency indicating a shear thinning behaviour. 12 Recently, rheological properties of three different nanocomposites, consisting of graphene oxide (GO), RGO, and polyhedral oligomeric silsesquioxane graed reduced graphene oxide (RGO-POSS) as nanollers with poly dimethyl siloxane (PDMS) matrices, were investigated by large amplitude oscillatory shear (LAOS).…”

“…12 They have found that moduli and viscosity of PMMA/RGO nanocomposites increased with increase in RGO loading, and a decrease in viscosity was observed with increasing frequency indicating a shear thinning behaviour. 12 Recently, rheological properties of three different nanocomposites, consisting of graphene oxide (GO), RGO, and polyhedral oligomeric silsesquioxane graed reduced graphene oxide (RGO-POSS) as nanollers with poly dimethyl siloxane (PDMS) matrices, were investigated by large amplitude oscillatory shear (LAOS). 13 They have noticed that different surface functionalization of nanoparticles resulted in different rheological behaviour due to the formation of different network-like structures.…”

A comprehensive study on morphological and rheological behavior of poly(ethylene terephthalate) and poly(ethylene‐2,6‐naphthalene) nanocomposite blends in presence of graphene

“…Since then, more attention has been paid to rheological properties of graphene/polymer nanocomposites focusing on the percolation threshold as one of the most important factors affecting the material properties or as a characterization parameter of the dispersion quality. Such a percolated system was studied by using polycarbonate/graphene composites , poly(propylene)/graphene nanocomposites , poly(methyl methacrylate)/graphene composites , and poly(methyl methacrylate)/reduced graphene oxide nanocomposites .…”