RAFT Polymerization of Styrene Mediated by Ferrocenyl-Containing RAFT Agent and Properties of the Polymer Derived from Ferrocene

Abstract

Two novel reversible addition−fragmentation chain transfer (RAFT) agents, (ferrocen-1-yl)ethyl benzodithioate (FEB) bearing ferrocenyl moiety in the R group, and benzyl ferrocenecarbodithioxylate (BFEC) bearing ferrocenyl moiety in the Z group, were designed and synthesized, respectively. The FEB and BFEC were then used as the RAFT agents for the controllable polymerization of styrene and their performance in the controllability was investigated respectively. Obtained polystyrenes were labeled as FEB−PS and BFEC−PS respectively. The results indicated that FEB and BFEC could make the polymerization of styrene very controllable, such as, the number-average molecular weight measured by gel permeation chromatography (M n,GPC) increases linearly with the monomer conversion, the M n,GPCs were close to the predicted values (M n,th), the polydispersity index (PDI) values were less than 1.25, and the chain-extension experiments of the obtained polymer with styrene were successfully carried out etc. The UV−vis absorption, electrochemical behavior and the stability in common organic solvents of the polystyrene with ferrocenyl group attached at the chain ends mediated by two RAFT agents, were further investigated. UV−vis absorption spectra of FEB−PS and BFEC−PS showed typical spectrum of ferrocene with a red shift from 440 to 475 nm and 560 nm, respectively. The electrochemical behaviors of FEB−PS and BFEC−PS were similar to that of ferrocene. E 1/2 (E 1/2 = (E p1+ E p2)/2) of FEB−PS was a negative shift, and E 1/2 of BFEC−PS was a large positive shift compared with that of ferrocene. The peak currents of FEB−PS and BFEC−PS gradually dropped with the increase of molecular weight of the polymers. The stability of BFEC−PS and FEB−PS in common organic solvents was in the order of CH2Cl2 > THF > acetone > CHCl3 > DMF. FEB−PS showed better stability than that of BFEC−PS in these solutions. The concentration of the polymers end-capped with ferrocenyl was calculated by the examination of iron contents using atomic absorption spectrometry and nuclear magnetic resonance (1H NMR) measurement, respectively. The results showed that the percentage of polystyrene end-capped with ferrocenyl in BFEC−PS and FEB−PS was about 80% and 70%.

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…7. The hb core polymer exhibited a high T g of about 250 C, which was similar to the previously obtained linear analogs (T g~2 50-300 C) [178].…”

“…Consequently, this effect is not expected for neutral backbones such as polystyrene. Hence, chemical reversibility was detected for singly ferrocene-labeled polystyrene prepared by reversible addition fragmentation chain transfer (RAFT) polymerization [178]. Interestingly, a single cobaltocene label entails chemical irreversibility of the electrode reaction in DMF, when being attached to poly(styrene) or poly(methacrylates) prepared by atom transfer radical polymerization (ATRP; see Fig.…”

“…In these cases, the use of redox mediators might help to overcome the problem. In some cases, the use of chemical 178 F. A. Plamper redox might then be the method of choice, allowing redox manipulation without considering the distance and the effective electron transfer between electrode and electroactive sites.…”

Click Chemistry: A Powerful and Versatile Methodology for Preparation of Ferrocene-Containing Polymers

“…[1][2][3][4][5][6][7]. Among the OMPs, ferrocene (Fc)-containing polymers (FcPs) are an important class [8][9][10][11][12][13][14][15][16][17]. Due to the ready availability, high stability, unique structure, and redox activity of Fc moiety, FcPs are drawing increasing interests in polymer science.…”

Novel anticancer and antibacterial organometallic polymer based on ferrocene as a building block and xanthone bioactive scaffolds: Synthesis, characterization, and biological study

“…[11][12][13][14][15][16][17] Because of unique properties of ferrocene (Fc)-containing polymers such as ready availability, high stability, unique structure, and redox activity of Fc moiety, these polymers are drawing increasing interests in polymer science and pharmaceuticals. [18][19][20][21][22][23][24][25][26][27][28] So far, various techniques have been applied for preparation of ferrocene containing polymers such as free radical, anionic, ringopening, cyclotrimerization and condensation polymerizations. [29][30][31][32][33][34][35][36][37][38][39] Obviously, these common polymerization methods have limitations that restrict their preparation.…”