Synthesis and Characterization of Partially Bio‐Based Aromatic (Co)polycarbonates Containing Biphenylene Units and Pendant Pentadecyl Chains

2-Pentadecyl-[1,1”-biphenyl]-4,4”-diol (PBD) is synthesized starting from cashew nut shell liquid—a by-product of cashew processing industry. A new series of partially biobased aromatic (co)polycarbonates possessing biphenylene units and pendant pentadecyl chains is synthesized by solution polycondensation of PBD or varying compositions of PBD and bisphenol-A with triphosgene in dry dichloromethane. Inherent viscosities and number average molecular weights of (co)polycarbonates are in the range 0.51–1.24 dL g−1 and 18 × 103– 43.4 × 103 g mol−1, respectively indicating the formation of reasonably high molecular weight polymers. Flexible, transparent, and free-standing films of (co)polycarbonates can be cast from chloroform solution. (Co)polycarbonates are characterized using Fourier transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric analysis. T10 and Tg values of (co)polycarbonates are in the range 417–433 and 8–147 °C, respectively. It is demonstrated that the Tg values can be tuned by incorporation of appropriate mol% of PBD as a comonomer in Bisphenol-A-based copolycarbonates. The lowering of the Tg values of (co)polycarbonates can be attributed primarily to the packing disruptive effect of flexible pentadecyl chains. Furthermore, the effect of incorporation of PBD as a comonomer on water contact angle values of (co)polycarbonates is evaluated.