Synthesis of polydimethylsiloxane‐containing block copolymers via reversible addition fragmentation chain transfer (RAFT) polymerization

Abstract

Low polydispersity polydimethylsiloxane (PDMS) was end functionalized with a reversible addition fragmentation chain transfer (RAFT) agent by the esterification of hydroxyl terminated PDMS with a carboxylic acid functional RAFT agent. These PDMS-RAFT agents were able to control the free radical polymerization of styrene and substituted styrene monomers to produce PDMScontaining block copolymers with low polydispersities and targeted molecular weights. A thin film of polydimethylsiloxane-block-polystyrene was prepared by spin coating and exhibited a microphase separated morphology from scanning force microscopy measurements. Controlled swelling of these films in solvent vapor produced morphologies with significant long-range order. This synthetic route will allow the straightforward production of PDMS-containing block copolymer libraries that will be useful for investigating their thin film morphological behavior, which has applications in the templating of nanostructured materials.

Nanopatterning and micropatterning of cobalt containing block copolymers via phase‐separation and lithographic techniques

“…55 PDMS-RAFT 5k and PDMS-RAFT 10k with 67 and 134 repeat units, respectively, were prepared. 55 These two samples were then used as macro-RAFT agents to polymerize monomer 1 (Scheme 1). Applying previously optimized RAFT polymerization conditions of 1, PDMS-RAFT 5k (2), CpCoCb monomer (1), MA, and AIBN in a 1:30:90:0.2 stoichiometric ratio were dissolved in nitrogen-saturated chlorobenzene (Scheme 1).…”

RAFT polymerization of N‐vinyl pyrrolidone using prop‐2‐ynyl morpholine‐4‐carbodithioate as a new chain transfer agent

“…After three freeze‐evacuate‐thaw cycles, the polymerization mixture was stirred at 55°C for 12 h. The plot of the monomer ln([ M ] o /[ M t ]) and (%) conversion versus time (Fig. 5) indicates that the monomer (%) conversion increases almost linearly upto around 52% conversion and followed the pseudo‐first‐order kinetics 41, 42. This behavior may be due to auto‐acceleration (gel‐effect) at higher monomer conversions.…”

Enhancement of icephobic properties based on UV-curable fluorosilicone copolymer films

“…CTA-PDMS-CTA was prepared by the DCC/DMAP catalyzed esterification of 4-cyanopentanoic acid dithiobenzoate (CPADB) with hydroxyl-terminated PDMS (HO-PDMS-OH), 33 whereas CPADB and HO-PDMS-OH were synthesized according were dissolved in 1.0 mL of TFT and placed in a 25 mL Schlenk tube which was thoroughly deoxygenated by three consecutive freeze-pump-thaw cycles. The tube was subsequently placed in an oil bath (70°C for the polymerization of 12FMA, and 80°C for the polymerization of 17FMA) for 10 h. The reaction was stopped by plunging the tube into liquid nitrogen.…”