Complex amphiphilic networks derived from diamine‐terminated poly(ethylene glycol) and benzylic chloride‐functionalized hyperbranched fluoropolymers

Abstract

Amphiphilic copolymer networks were prepared from hyperbranched fluoropolymer (HBFP*, Mn = 38 kDa, by atom transfer radical‐self condensing vinyl copolymerization) and linear diamine‐terminated poly(ethylene glycol) (DA‐PEG, Mn = 1,630 Da). Model studies found that the crosslinking mechanism occurred at ambient temperature as a result of reaction between DA‐PEG and the benzylic chlorides of HBFP*. These networks underwent covalent attachment to glass microscope slides derivatized with 3‐aminopropyltriethoxysilane, whereupon gel percent studies at various weight percentages of DA‐PEG to HBFP* found that curing could be achieved at lower temperatures and shortened time periods relative to the previously reported parent HBFP–PEG system. Thermogravimetric analysis revealed that the crosslinked materials gave no evident mass loss up to 250 °C. Differential scanning calorimetry of the complex amphiphilic networks showed a suppressed glass transition temperature, relative to that observed for neat HBFP*, and multiple melting DA‐PEG endotherm(s) near 30 °C. The films possessed a topographically‐complex surface with features that increased in tandem with an increase in the ratio of DA‐PEG to HBFP*, as detected by atomic force microscopy and quantified by increased rms roughness values. Internal reflection infrared imaging revealed a heterogeneous surface composition and confirmed that the domain sizes increased as the weight percent of DA‐PEG increased. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4782–4794, 2006

Hyperbranched Fluoropolymers and their Hybridization into Complex Amphiphilic Crosslinked Copolymer Networks

“…30%, with a fluorine content of 24-33 wt.-%, which was controlled through the molar feed ratio of PFS to CMS. The benzylic chlorides that were present within HBFP (II) are much more reactive electrophiles than are the pentafluorophenyl groups, [43] and these alkyl halides allowed for further polymer chain formation, derivatization, and crosslinking either through ATRP or nucleophilic substitutions. HBFP (II) had a T g of 95-106 8C…”

“…The content of this feature article will build from these amphiphilic types of materials, with emphasis upon the production of amphiphilic crosslinked networks that combine all desired features of compositional and structural heterogeneity, being composed of HBFPs and linear PEG. [41][42][43] These materials were developed initially as non-toxic, anti-biofouling coatings for application in the marine environment, and they have demonstrated remarkable perormance toward this application. [44] Moreover, their complex morphologies were also found to provide nanochannels that exhibit unusual thermallypromoted release of volatile guest molecules, [45] and nanoscale confinement of water swollen within the materials to result in dramatically increased moduli.…”

Synthesis of Fluorinated Amphiphilic Block Copolymers Based on PEGMA, HEMA, and MMA via ATRP and CuAAC Click Chemistry

“…The signals which appeared in the spectrum of 2,3,4,5,6-pentafluorobenzyl azide also existed in that of click product. The signals detected at -142 ppm, -151 ppm, and -161 ppm originated from the aromatic fluorines: 2F at o-position, 1F at p-position, and 2F at m-position, respectively [44]. …”

Solid‐State NMR Investigations of the Unusual Effects Resulting from the Nanoconfinement of Water within Amphiphilic Crosslinked Polymer Networks

“…Two types of solid-state 19 F NMR spectroscopy experiments were used to characterize the HBFP domains of the phase-separated HBFP-PEG block copolymers. Mobile (soft) domains were detected by a rotor-synchronized Hahn echo under magic-angle spinning conditions, [26] and rigid (hard) domains by a solid echo with no magic-angle spinning.…”

“…Such systems can be prepared readily, but often pose unique challenges in the characterization of their heterogeneous structures and morphologies. Surface analyses have observed compositional heterogeneity [19] and complex topographies [20] for amphiphilic crosslinked networks. Small-angle neutron scattering (SANS), [21] X-ray, [22] transmission electron microscopy (TEM), [23] and electron paramagnetic resonance (EPR) [24] studies have confirmed the extension of the morphological heterogeneity in addition to nanoand microphase segregation throughout the bulk of such materials.…”