The mechanical and physical properties of microcrystalline cellulose (MCC)/sisal/PMMA hybrid composites for dental applications

Abstract

The study on polymethyl methacrylate (PMMA)-based composites in dental applications has gained much interest in recent years, resulting in many exciting studies worldwide. In those research, various filler types of reinforcing PMMA have been studied extensively. This study combines the microcrystalline cellulose (MCC) particles (0, 1, 2, 3, 5 vol.%) and sisal fiber to strengthen PMMA. We investigate their effects on the flexural, impact, hardness, compressive strength, water absorption, and thermal properties of (MCC)/sisal/PMMA hybrid composites. Scanning electron microscopy (SEM), universal testing machine (UTM), hardness Vickers, thermogravimetry analysis (TGA), and ANSYS Workbench 2022 R1 software are utilized to characterize the properties of the composites. X-ray diffraction (XRD) is used to characterize the degree of crystallinity of MCC and sisal fiber. Adding MCC to alkali-treated sisal/PMMA decreases the flexural and impact strengths but increases the hardness. Adding 1 and 2 vol.% MCC produces maximum flexural and impact strength and hardness values. Simulation on a composite added with 1% MCC by applying a full force load of 14.4 N yields compressive strength of 42.56 MPa. Thermal stability of all composites with and without MCC shows similarity until 250 °C but gradually degrades at over 250 °C, particularly for composites with MCC. Besides, as the addition of MCC increases, the water absorption also increases, with the lowest value of 37.54 μg mm−3 obtained by the composite added with 1 vol.% MCC, which is within the range of the standard dental materials.