The effect of a novel BYK dispersant for MWCNT on flexural properties of epoxy nanocomposites and hybrid carbon fiber composites

In this study, multi-walled carbon nanotubes modified with and without BYK dispersant were utilized to improve the flexural strength properties of epoxy nanocomposites and hybrid carbon fiber composites. The goal of the addition of BYK dispersants is to reduce the viscosity factor of epoxy resins and prevent the agglomeration phenomenon, which leads to a higher dispersion degree for carbon nanotubes in the resin. Three samples of nanocomposites were prepared utilizing ultrasonication technique at 0.1 wt% of MWCNT, namely MWCNT/ epoxy nanocomposites unmodified with BYK and MWCNT/epoxy nanocomposites modified with BYK as well as pure epoxy. The samples have been dispersed and prepared at equal and constant times. The purpose of that is to perform a comparison among these products of nanocomposites. Flexural strength measurements were per-formed to determine the optimum nanocomposite. The MWCNT/epoxy nanocomposite modified with BYK dispersant was the best type. The flexural strength and modulus for this type were increased by approximately 23% and 52%, respectively.The nanophase resins for these aforementioned nanocomposites were utilized to improve the mechanical properties of carbon fiber composites utilizing hand lay-up technique. Three samples were produced, namely CF/ epoxy modified by MWCNT without BYK, CF/epoxy modified by MWCNT with BYK and CF/pure epoxy. Flexural strength measurements were also conducted to estimate the mechanical properties of hybrid fiber composites. The CF/epoxy modified by MWCNT with BYK was the optimum hybrid composite, where the flexural strength and modulus for this type were improved by approximately 27% and 8%, respectively. TEM and SEM were utilized to check the degree of dispersion and exfoliation of nanotubes in the epoxy resin, plus to explain the reasons behind the failure of composites under flexural loads.In conclusion, the addition of BYK dispersants to a mixture of MWCNT and epoxy resin contributes to improving the degree of dispersion and alignment of nanotubes in the matrix. Thus, this leads to an increase in the strength properties of epoxy nanocomposites. The addition of optimized and strengthened nanocomposite with BYK to fiber composites also led to an increase in the flexural strength properties of hybrid carbon fiber composites.