Bio-based Poly(e-caprolactone) from Soybean-Oil Derived Polyol via Ring-Opening Polymerization

In this work, a new series of bio-based poly(e-caprolactone)s (SBO-PCLs) is synthesized through ring-opening polymerization (ROP) of e-caprolactone (e-CL) using stannous octoate as a catalyst and hydroxylated soybean oil (SBO-OH) as a macro-initiator. For this purpose, firstly, epoxy groups of epoxidized soybean oil (ESBO) are converted to hydroxyl functionalities to be used for ROP of e-CL. Then, after the ROP of e-CL using SBO-OH; wettability, biodegradability and thermal properties of the obtained SBO-PCLs are evaluated in terms of loading ratio of e-CL monomer ([OH]/[e-CL] (n/n) = 1:0.5; 1:1 and 1:2). The obtained SBO-PCLs and their intermediates are characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (H-1-NMR), gel permeation chromatography (GPC), water contact angle measurement (WCA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and enzymatic degradation experiment. SBO-PCL with higher PCL molar ratio shows the lower biodegradability, but higher hydrophobicity and thermal properties compared to others. Thus, it is clear that the successful syntheses of SBO-PCLs encourage the use of these polymers as promising materials for scientists working on PCL applications.