Poly(N‐vinylpyrrolidone)–polydimethylsiloxane amphiphilic ABA triblock copolymers

Abstract

Triblock copolymers of N‐vinylpyrrolidone (NVP) and polydimethylsiloxane (PDMS) were synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization using two different types of difunctional telechelic PDMS‐based dixanthate macroinitiators. The incorporation of PDMS into the triblock copolymers was evidenced by 1H NMR spectroscopy and varied between 4 mol % and as high as 20 mol %, dependent on reaction time and monomer conversion. The copolymer homogeneity was characterized in terms of molecular weight distribution determined by GPC to estimate the level of control over the chain length. Monomodal molecular weight distributions were observed, and 1H NMR spectroscopy indicated the copolymers had number average molecular weights (Mn) ranging between 28,000 and 160,000 g/mol. In addition, thin film phase separation and critical micelle concentrations for these copolymers were analyzed via transmission electron microscopy and surface tension measurements, respectively. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3387–3394

Polydimethylsiloxane Polymerized Emulsions for Acoustic Materials Prepared Using Reactive Triblock Copolymer Surfactants

“…PDMS mCTA was synthesized following a modified protocol from a previous literature report . Hydroxy-terminated PDMS (20.0 g, 2 mmol, 10,000 g/mol), DDMAT (1.83 g, 5 mmol), and DMAP (98 mg, 0.8 mmol) were dissolved in 150 mL of anhydrous DCM in a flame-dried round-bottom flask equipped with a stir bar.…”

“…PDMS mCTA was synthesized following a modified protocol from a previous literature report. 63 Hydroxy-terminated PDMS (20.0 g, 2 mmol, 10,000 g/mol), DDMAT (1.83 g, 5 mmol), and DMAP (98 mg, 0.8 mmol) were dissolved in 150 mL of anhydrous DCM in a flame-dried round-bottom flask equipped with a stir bar. A solution of DCC (1.65 g, 8 mmol) in 50 mL of anhydrous DCM was added to the reaction mixture, the round-bottom flask was sealed with a septum, and the reaction mixture was transferred to an oil bath preheated to 40 °C and allowed to stir for 24 h. The reaction was cooled to room temperature before the solids were removed using vacuum filtration, and the organic layer was collected and then concentrated under rotary evaporation to yield a viscous yellow oil.…”

Recent Advances in the Synthesis of Complex Macromolecular Architectures Based on Poly(N-vinyl pyrrolidone) and the RAFT Polymerization Technique

“…Initial studies revealed that these triblocks were highly surface active in aqueous media and can selfassemble in bulk providing spherical PDMS structures. Commercially available PDMS with rather broad molecular weight distribution bearing hydroxypropyl groups at both chain ends was transformed to bifunctional macro-CTA after reaction with bromopropionylbromide followed by reaction with potassium O-ethyl xanthate (Scheme 65) [156]. Subsequent polymerization of NVP in THF at 60 • C with AIBN afforded the PNVP-b-PDMS-b-PNVP triblock copolymers.…”