Author(s): Almeida, Carlos M.F. ; Costa, Hugo Davide ; Kadhirvel, Porkodi ; Queiroz, Ana ; Dias, Rolando ; Costa, Mário Rui
Date: 2016
Persistent ID: http://hdl.handle.net/10198/13992
Origin: Biblioteca Digital do IPB
Project/scholarship: info:eu-repo/grantAgreement/FCT/COMPETE/PEst-C%2FEQB%2FLA0020%2F2013/PT;
Subject(s): Batteries; Crosslinking; Electrochemistry; Fuel cells; Inverse-vulcanization; RAFT polymerization
Novel results concerning the inverse vulcanization of sulfur using reversible addition–fragmentation chain transfer (RAFT) polymerization are here reported. It is shown that RAFT polymerization can be used to carry out this cross-linking process, with the additional possibility to extend the reaction time from a few minutes as with classical free radical polymerization (FRP) to several hours. Higher control on viscosity and processability of the synthesized networks, as well as, the implementation of semibatch feed policies during cross-linking are important advantages of the RAFT process here explored comparatively to the FRP inverse vulcanization. Using cyclic voltammetry, it was assessed the electrochemical activity of the synthesized sulfur-rich polymer networks. It is shown that the fundamental electrochemical activity of the elemental sulfur was preserved in the produced materials. Testing of electrochemical cells assembled with lithium in the anode and different sulfur based materials in the cathode, including the synthesized RAFT networks, is also shown. The results here presented highlight the new opportunities introduced by reversible-deactivation radical polymerization mechanisms on the control of the synthesis process and in the design of such advanced materials and show also that many potential derivatizing possibilities can be achieved.
The authors thank FCTand FEDER under Programme COMPETE (Project PEst-C/EQB/LA0020/2013), QREN, ON2, and FEDER (Project NORTE-07-0162-FEDER-000050), and QREN, ON2, and FEDER (Project NORTE-07-0124-FEDER-0000014—Polymer Reaction Engineering).We acknowledge TIMCAL Graphite & Carbon for supplying the conductive carbon C65. This work was also financially supported by Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE/LCM funded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalizac¸~ao (POCI) – and by national funds through FCT – Fundac¸~ao para a Ci^encia e a Tecnologia.
