No abstract

Ricinoleic acid (RA) is a component of various bio‐based copolymers. However, high‐molecular weight polyricinoleate homopolymers are not widely investigated due to high cost of commercial monomer and catalysts. In this work, we present low‐cost approach for the synthesis of high‐molecular‐weight polyricinoleate by preparing large amount of pure monomer and use of lipozyme TL IM as catalyst. First, polymerization conditions were optimized and comparative studies of medium‐molecular‐weight polyricinoleate (PRA‐M) of Mw = 30 000 gmol−1 and high‐molecular‐weight polyricinoleate (PRA‐H) of Mw = 72 000 gmol−1 were conducted. Polyricinoleates were characterized by common spectroscopic, chromatographic, and thermal methods. Solvent casting of polyricinoleates resulted in thin and continuous coating with perfectly smooth surface under SEM observation. AFM analysis of PRA films showed that surface roughness decreased with increasing molecular weight of polyricinoleate (roughness PRA‐M = 68.39 nm and PRA‐H = 57.36 nm). Degradation studies under in vitro conditions showed that both PRA‐M and PRA‐H showed good stability with only ~2% of mass loss after 6 months, possibly due to its hydrophobic nature and relatively high‐molecular weight. In contrast to RA, PRA‐M and PRA‐H do not have significant antibacterial effect on Staphylococcus aureus and Escherichia coli. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48172.

Ferrocene (Fc) functionalization of macroporous polyacrylamide‐based cryogel (PAAm‐Epx) is achieved by click chemistry. For this purpose, firstly, PAAm‐Epx cryogel with azide functionality (PAAm‐N3) is prepared by using acryalmide (AAm) as the monomer and allyl glycidyl ether (AGE) as the co‐monomer followed by subsequent ring opening reaction of epoxide ring of AGE in acidic medium. Azide groups of PAAm‐N3 is then modified with ethynyl ferrocene, leading to the redox active cryogel (PAAm−Fc) together with preserving the unique characteristic properties of the virgin PAAm‐Epx cryogel. Swelling, mechanical and morphological behaviours of PAAm‐Epx, PAAm‐N3 and PAAm−Fc are investigated. Detailed characterization of the PAAm−Fc is carried out by several techniques such as FTIR (Fourier Transform Infrared Spectroscopy), Scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM‐EDX), Inductively Coupled Plasma Optical Emmision Spectrometry (ICP‐OES, Cyclic (CV), and Differential Pulse Voltammetry (DPV). Electrochemical analysis confirms the electroactivity and the presence of chemically linked ferrocene unit to the cryogel.