Effect of ionic liquid anion and cation on the physico-chemical properties of poly(vinylidene fluoride)/ionic liquid blends

Poly(vinylidene fluoride), PVDF, has been blended with different ionic liquids (IL) in order to evaluate the effect of the different IL anions and cations on the electroative -phase, thermal, mechanical and electrical properties of the polymer blend. [C2MIM][Cl], [C6MIM][Cl], [C10MIM][Cl], [C2MIM][NTf2], [C6MIM][NTf2], [C10MIM][NTf2] have been selected and were introduced in the polymer at a weight percentage of 40 wt%. It was found that the incorporation of ILs into the PVDF matrix leads to an increase of the -phase content due to the strong electrostatic interactions between the dipolar moments of PVDF and the ILs. Further, the incorporation of ILs into PVDF strongly decreases the elastic modulus and increases the electrical conductivity of the blend with respect to the pure polymer matrix, all these effects being accompanied by a modification of the crystallization kinetics, as indicated by the modified spherulitic microstructure. Thus, novel PVDF/IL blends films with high transparency, excellent antistatic properties, and highly polar crystal form fraction were successfully achieved.

This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the projects PEST-C/QUI/UIO686/2013, PEST-C/FIS/UI607/2014, UID/Multi/04551/2013 and PTDC/QUI-QUI/117340/2010. The authors also thank funding from Matepro – Optimizing Materials and Processes”, ref. NORTE-07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 – O Novo Norte), under the “Quadro de Referência Estratégico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER). The authors also thank Support by the project SIMPE- Interative multitouch surfaces based on electroactive polymers - QREN-ADI- 23122, through the COMPETE program. JCD thanks the FCT for the SFRH/BD/90215/2012 grant.