Comparison of Rheological Characteristics and Mechanical Properties of Fossil-Based and Bio-Based Polycarbonate

Fossil-based PC, bisphenol-A polycarbonate (BPA-PC), is polymerized using bisphenol-A, which is derived from fossil-fuel based chemicals. Bio-based polycarbonate (bio-based PC) is polymerized using isosorbide, which is taken from plants. Accordingly, bio-based PC does not contain toxic polymerization chemicals. The rheological characteristics of fossil-based PC and bio-based PC samples, including viscosity, storage and loss moduli, and melt tension, were studied and compared. The mechanical properties of tensile behavior and impact strength were also measured and discussed. The shear viscosity curves and storage and loss moduli patterns of the bio-based PC were found to be somewhat different from those of fossil-based PC. The bio-based PC had higher tensile strength and elastic modulus than the fossil-based PC. The fossil-based PC exhibited a stress jump in the high strain region of the stress-strain curve, while the bio-based PC exhibited no stress jumps. The bio-based PC had a lower impact strength than the fossil-based PC. The cross-section of the fractured impact specimen of the bio-based PC showed only mirror regions, while that of the fossil-based PC showed both mirror regions and misted regions.