Mechanical strength study of polyester blend vinyl ester composite material reinforced by empty oil palm fruit bunch fibers as raw material for vehicle bumpers

Abstract The use of polymer materials as matrices for manufacturing composite materials is employed in various technological applications, including vehicle bodies. The advantages of polymer materials include lightness and moisture resistance; however, this material still exhibits low mechanical strength. To increase its mechanical strength, it is necessary to combine it with reinforcing materials derived from natural fibers or synthetic fibers. One way is to strengthen it with empty palm oil signs. After researching composite materials made from mixed polymer materials of polyester polymers with vinyl esters reinforced with palm oil bunch fibers, an increase in flexural strength of 183.34 N was observed, whereas for mixed polyester and vinyl ester matrices without palm oil bunch fibers or pure matrix polymers, the increase was only 138.33 N, this increase occurred in the mixed polyester and vinyl ester polymer matrix, comprising 85 wt% and palm oil bunch fibers at 15 wt%, with an average of 183.34 N compared to pure polyester, which was only 138.33 N, representing an increase of 132.54%. Furthermore, the test results show that the maximum flexural stress value for each matrix material of polyester and vinyl ester polymer mixture and oil palm bunch fibers (FPO) can increase the maximum flexural stress value of pure polyester and vinyl ester mixture polymer without reinforcing fibers from oil palm bunch fibers by 83.092 MPa, while with the addition of oil palm bunch fibers up to 15% by weight can increase the flexural stress value of the material up to 110.086 MPa. The addition of oil palm bunch fibers to the polymer matrix of polyester and vinyl ester mixture by 15% by weight can increase the stress by 132.49%.