Study On Mechanical Properties Of 3-D Braided Fibers Reinforced Bismaleimide Composites

During the research of resin which is used for Resin Transfer Molding (RTM),bismaleimide has attracted much attention. Bismaleimide is an engineering plasticwith good processability and excellent mechanical properties under high temperature.Bismaleimide is widely used in high-tech field such as aviation, navigate andspaceflight.3-D braiding technique can fabricate integrated fabrics. 3-D braided compositescan offer good mechanical properties such as high delaminating resistance and impactdamage tolerance. The architecture of braided fibers can be designed in a wide range.In this paper, 3-D braided carbon fiber, 3-D braided Kevlar fiber, and 3-Dbraided hybrid fiber reinforced BMI composites (denoted as C3D/BMI, K3D/BMI, andHF3D/BMI, respectively) were prepared, and their mechanical properties and affectingfactors were determined.Studies in this paper include: Influence of fiber structure and volume fraction onflexural strength and flexural modulus, shear strength and impact strength of C3D/BMIand K3D/BMI. Influence of wear properties on the mechanical properties of HF3D/BMIand existence of hybrid effect on some properties. The effect of fiber surfacetreatment on properties of C3D/BMI and K3D/BMI, and SEM and XPS analyses. Themoisture absorption behaviors of fiber-reinforced BMI composites. Various factorsthat influence moisture absorption behaviors of composites and variations ofmechanical properties as a result of moisture absorption. In vitro tests so as to assessbiocompatibility of the composites. Comparisons of properties among C3D/BMI,K3D/BMI, HF3D/BMI, C3D/EP, and C3D/MCPA composites.Our experimental results showed that the 3-D braided fiber reinforced BMIcomposites exhibited much higher flexural strength than human bones while theirmodulus matched that of human bones, which helps alleviate the so-called "stressshielding" effect. No obvious decline in the mechanical properties was observed afterthe moisture absorption. No obvious leachable substances were detected in the presentwork. The 3-D braided fiber reinforced BMI composites are believed to be promisingmaterials for bone fracture fixation.