Effect of microcrystalline cellulose on the mechanical properties of flax reinforced methylmethacrylate and urethane acrylate composites

Many structural applications are attracted to natural fibre-reinforced polymeric composites due to their eco-friendliness, recyclability, and cost-effectiveness. While significant progress has been made, their interface compatibility with the polymeric matrix is still challenging. Therefore, the present study proposed a method for improving the mechanical and dynamic mechanical performance of flax-reinforced novel methylmethacrylate (Elium (R)) and urethane acrylate (Crestapol (R)) composites. The technique involved the dispersion of microcrystalline cellulose (MCC) in the matrix at different weight percentages (0.5-0.75%) to improve the fibre/matrix interface. Flax/Elium (R) (FE) and flax/Crestapol (R) (FC) composites with varying weight percentages of MCC were manufactured using the vacuum infusion method. The resulting improvements in mechanical and dynamic properties were evaluated through in-plane shear (+/- 45 degrees tensile), flexural, short beam shear, and dynamic mechanical analysis (DMA). The effects of MCC on these properties of flax/Elium (R) were compared to those of flax/Crestapol (R) composites. The addition of MCC improved the in-plane shear strength (FE: 13-20%, FC: 10-17%), flexural strength (FE: 6-13%, FC: 13%) and interlaminar shear strength (FE: 9-17%, FC: 10-20%). Also, FE composite showed 7-11%, 10-14% and 10-17% higher in-plane shear, flexural and interlaminar shear strengths, respectively, compared to FC composites. The DMA results confirmed the positive effect of Elium (R) resin and MCC on the dynamic storage and loss modulus.