The impact of graphene nanofiller loading on the morphology and rheology behaviour of highly rigid polyurethane copolymer

Abstract

This work attempts to study the effects of the addition of graphene nanoplatelets (xGNP) on the rheology properties of new version of polyurethane copolymer with 1,5 pentane diol as chain extender , containing a high amount of hard blocks. Two- step polymerisation was employed to synthesise this kind of polymer. The thermal and electrical conductivity of this copolymer was also investigated. Meanwhile, the rheology response has been analysed by measuring the viscosity It was found that the viscosity increases by 68% and 2 × 105% at loadings of 0.5 wt.% and 15 wt.% of xGNP, respectively, compared with that of neat polyurethane copolymer. This means that the melt viscoelastic behaviour of highly rigid polyurethane copolymer (HRPUC) is influenced by the presence of xGNP contents, transforming the behaviour of nanocomposite from liquid-like to solid-like. This result was attributed to the network formation and interaction between hard segments of the HRPUC structure and xGNP due to strong shear thinning behaviour. In addition, the thermal conductivity of HRPUC increases to 0.97 W m−1.k (410%), electricity conductivity rose to 102 s m−1 (1000%). SEM morphology images showed overall dispersion of xGNP in the HRPUC, implying a reduction in the interspacing of flakes with increasing xGNP concentration. Further investigation into HRPUC morphology and its nanocomposites was conducted using the TEM method, illustrating that the xGNP stacking resulted from poor ability to disperse at greater loadings of xGNP.

The Effect of Addition Graphite Filler on Mechanical Properties of Epoxy Material

“…To evaluate the status of dispersion and distribution of graphite within epoxy, SEM observation was carried out. However, as the loading of graphite increased to 2%wt, several aggregations occurred due to insufficient mixing process to achieve the higher dispersion [1,31]. This observation was also suggested by previous literature by the author R. Baptista who fund that increasing graphite tended to form small agglomerates as well as several pores presenting in the epoxy matrices [22].…”

“…Since the past two decades, research into composites has led to the development properties of materials not only the parent materials but also of classic micro composites [1,2]. Composite materials are hybrid materials where various fillers/ reinforcements with at least one dimension in the micro-nanometer scale incorporated with different matrices [3,4].…”

A Compressive Review on Swelling Parameters and Physical Properties of Natural Rubber Nano composites

“…Table 2 shows the swelling rates results, which calculated according to equation 2, the swelling ratios gradually decrease with the increase in the content of the nanoparticles due to the diffusion and good dispersion of the nanoparticles in the rubber matrix and the growth of crosslinking. During the treatment process, the rate of swelling decreases with the highest crosslinking density and reaches its peak at NR / 3 MMT [43], these results support the hypothesis that increased crosslinking strengthens the rubber matrix [43][44][45][46]. ________________________________________________ Egypt.…”

Effect of OMMT reinforcement on morphology and rheology properties of polyurethane copolymer nanocomposites

“…The PUC/75 with higher number of hard segments *75 wt.% was synthesized using a pre-polymer method (two steps polymerization) as reported in previous study 30 and shows in Figure 1. The melt blending method was used to prepare PUC/OMMT nanocomposites.…”