Block copolymers containing stable radical and fluorinated blocks with long-range ordered morphologies prepared by anionic polymerization. Issue 37 (28th August 2019)

• Record Type: Journal Article
• Authors: Cintora, Alicia; Takano, Hiroki; Khurana, Mohit; Chandra, Alvin; Hayakawa, Teruaki; Ober, Christopher K.
• Is Part Of: Polymer chemistry. Volume 10:Issue 37(2019)
• Page Start: 5094
• Page End: 5102
• Publication Date: 2019-08-28
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c9py00416e
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Synthesis conditions for the anionic polymerization of PTMA, PTFEMA and PTMA- b -PTFEMA are reported, long-range ordering of the block copolymers is characterized. Abstract : We report a facile synthetic approach to create stable radical block copolymers containing a secondary fluorinated block via anionic polymerization using a bulky, sterically hindered countercation composed of a sodium ion and di-benzo-18-crown-6 complex. The synthetic conditions described in this report allowed for controlled molecular weights and dispersity (<1.3) of both homopolymers: poly(2, 2, 6, 6-tetramethyl-1-piperidinyloxy-methacrylate) (PTMA) and poly(2, 2, 2-trifluoroethyl methacrylate) (PTFEMA) as well as their block copolymers (PTMA- b -PTFEMA). The stable radical concentration of the polymers was determined by electron spin resonance (ESR) and showed radical content above 70%. An analysis of the microphase morphologies in PTMA- b -PTFEMA thin films via atomic force microscopy (AFM) and grazing incidence small angle X-ray scattering (GISAXS) showed clear evidence of long-range ordering of lamellar and cylindrical morphologies with 32 and 36 nm spacing, respectively. The long-range ordering of the morphologies was developed with the aid of two separate neutral layers: PTMA- ran -PTFEMA- ran -poly(hydroxyl ethyl methacrylate) (PHEMA) and poly(isobutyl methacrylate) (PiBMA)- ran -PTFEMA- ran -PHEMA, which helped us corroborate, along with the Zisman method, the surface energy estimation of PTMA to be 30.1 mJ m −2 .