Enhancement of the Thermomechanical Properties of a Fly Ash- and Carbon Black-Filled Polyvinyl Chloride Composite by Using Epoxidized Soybean Oil as a Secondary Bioplasticizer

Plasticized polyvinyl chloride (PVC) was fabricated using epoxidized soybean oil (ESBO) as a secondary bioplasticizer with dioctyl phthalate (DOP). The PVC/MFA/CB composites were prepared by melt mixing of the plasticized PVC with modified fly ash (MFA), carbon black N330 (CB), and polychloroprene (CR) in a Haake Rheomix mixer using a rotation speed of 50 rpm at 175°C for 6 min and then compressed by Toyoseiki pressure machine under 15 MPa. The effect of ESBO content on morphology, melt viscosity, tensile properties, and flame retardancy of PVC/MFA/CB composites was investigated. The obtained results showed that the incorporation of ESBO has significantly enhanced the processing ability, Young’s modulus, tensile strength, and elongation at break of the PVC/MFA/CB composites. The torque of PVC/MFA/CB composites was increased to approximately 12% when 50 wt% of DOP was replaced by ESBO. When ESBO was 20 wt% in comparison with DOP weight, the elongation at break, tensile strength, and Young’s modulus of the composites were increased to 48%, 24%, and 4.5%, respectively. Correspondingly, thermogravimetric analysis results confirmed that ESBO had improved the thermostability of the PVC composites. The ESBO have potential as a secondary bioplasticizer replacement material for DOP owing to their better thermomechanical stability.