Effect of block copolymer containing ionic liquid moiety on interfacial polarization in PLA/PCL blends

Compared with poly(-caprolactone)-b-poly(ethylene glycol) block copolymer (BC), a systematic study of the effect of the concentration of the compatibilizer, poly(-caprolactone)-b-poly(ethylene glycol) BC containing ionic liquid moiety (BCIL), on the interfacial properties of a phase separating blend of poly(l-lactic acid)/poly(-caprolactone) (PLA/PCL) was performed. BCIL copolymer as a compatibilizer for immiscible PLA/PCL blend can reinforce the interactions between the two polymeric phases by the IL electrostatic interaction at interphase, and the particle size of PCL decreases because of interfacial reinforced-compatibilization of IL moiety. Ion mobility of IL moiety at interphase and PCL phase for PLA/PCL/BCIL blend can induce interfacial blocking of charge carriers, and IL moiety segregating mainly at the interface can decrease the relaxation rate and increase the dielectric strength of interfacial polarization. Our results provide a methodology to characterize and tune the morphology and blocking of charge carriers with the aim of tailoring the dielectric interfacial properties of blends. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46161.