This article highlights the preparation of perfluorocyclobutyl (PFCB) aryl ether polymers for a multitude of commercial technologies that are of academic and commercial global interest. In this account, the synthesis of various aryl trifluorovinyl ether (TFVE) monomers tailored for specific applications is

Metastable composites were prepared from a fl uoropolymer-coated nano-aluminum blended formulation entrained in an epoxy matrix. This composition produced a moldable/post-machinable composite that undergoes thermally activated metal-mediated oxidation. The simplistic, scalable design can warrant consideration for a new class of engineered metal-based fl uoropolymer pyrolant composite systems. As featured in:See S. Fluoropolymers have long served as potent oxidizers for metal-based pyrolant designs for the preparation of energetic materials. Commercial perfluoropolyethers (PFPEs), specifically known as FomblinsÒ, are wellknown to undergo accelerated thermal degradation in the presence of native metals and Lewis acids producing energetically favorable metal fluoride species. This study employs the use of PFPEs to coat nano-aluminum (n-Al) and under optimized stoichiometric formulations, harness optimized energy output. The PFPEs serve as ideal oxidizers of n-Al because they are non-volatile, viscous liquids that coat the particles thereby maximizing surface interactions. The n-Al/PFPE blended combination is required to interface with an epoxy-based matrix in order to engineer a moldable/machinable, structurally viable epoxy composite without compromising bulk thermal/mechanical properties. Computational modeling/ simulation supported by thermal experimental studies showed that the n-Al/PFPE blended epoxy composites produced an energetic material that undergoes latent thermal metal-mediated oxidation.Details of the work include the operationally simple, scalable synthetic preparation, thermal properties from DSC/TGA, and SEM/TEM of these energetic metallized nanocomposite systems. Post-burn analysis using powder XRD of this pyrolant system confirms the presence of the predominating exothermic metal-mediated oxidized AlF 3 species in addition to the production of Al 2 O 3 and Al 4 C 3 during the deflagration reaction. Details of this first epoxy-based energetic nanocomposite entrained with a thermally reactive formulation of PFPE coated n-Al particles are presented herein.

The synthesis and characterization of solution processable, semi-fluorinated perfluorocyclobutyl (PFCB) aryl ether polymers possessing covalently bound pendant polyhedral oligomeric silsesquioxanes (POSS) cages is reported. The synthesis of POSS aryl trifluorovinyl ether (TFVE) monomers was accomplished by the condensation of commercial monosilanolalkyl-POSS with a TFVE-functionalized chlorosilane. POSS TFVE monomers were elucidated by 1H, 19F, 13C, and 29Si NMR spectroscopy, ATR-FTIR analysis, and elemental (C, H, and F) combustion analysis. Bulk thermal copolymerization of POSS TFVE monomers afforded random and block PFCB aryl ether copolymers functionalized with various POSS loadings. Quantitative monomer conversion was monitored by 19F NMR, which produced copolymer number-average molecular weights (M n) of (19.5−24.9) × 103 (in CHCl3 using polystyrene as standard) determined by gel permeation chromatography (GPC). Thermal properties of POSS PFCB aryl ether copolymers were evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Transmission electron microscope (TEM) analysis of spin cast optically transparent, flexible POSS PFCB aryl ether copolymer films revealed the presence of 5−20 nm-sized POSS agglomerates. Optical profilometer analysis of spin and drop cast film surfaces exhibited a modest increase in surface roughness of POSS PFCB aryl ether copolymers as compared to PFCB aryl ether homopolymers without POSS inclusion. The POSS copolymers exhibited a modest increase in hydrophobicity as measured by static water contact angle analysis. Synthesis, characterization, thermal analysis, and unique surface features of POSS PFCB aryl ether copolymers are discussed.

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New fluorovinylene aromatic ether polymers, possessing dual reactivity, have been successfully prepared via the step-growth polymerization of commercial bis(trifluorovinyl) aromatic ethers and bisphenols.

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The synthesis and hyperpolarizabilities of a series of push−pull chromophores containing a bis-(4-methoxyphenyl) amine donor and efficient acceptor bridges with thiophene and ring-locked polyene are presented. The chromophores are readily soluble in common organic solvents and exhibit high thermal decomposition temperatures (highest T d was 358 °C). Molecular hyperpolarizabilities (β) of the chromophores were measured by hyper-Raleigh scattering at 1604 nm (highest β was 20 000 × 10−30 esu). The electrochemical behavior of the chromophores was studied by cyclic voltammetry and agreed well with the observed intrinsic nonlinearities. In addition, preliminary results of conjugated polyene chromophores containing aryl trifluorovinyl ether monomers were synthesized and copolymerized via thermal cyclodimerization, affording perfluorocyclobutyl aryl ether polymers with high glass transitions (highest T g was 224 °C) and a good thermal stability (typical T d was >350 °C). These chromophores can be used to develop electro-optic materials due to their large optical nonlinearities, good absorption characteristics, high thermal stability, and excellent solubility with organic solvents and polymeric materials.

New fluorinated arylene vinylene ether (FAVE) polymers were prepared by a facile, metal-free condensation polymerization of fluorene, phenylenevinylene, dithiophene, or thiadiazole chromophore-containing bisphenols with bis(trifluorovinyloxy)biphenyl. The addition of chromophores encapsulated into the polymers were prepared in good yields and characterized by 1 H and 19 F NMR and GPC. Thermal analysis by differential scanning calorimetry (DSC) confirmed the polymers are entirely amorphous and are easy to solution process, producing optically transparent, flexible films. Thermal gravimetric analysis (TGA) showed they possess high thermal stability with decomposition temperatures of 340-387°C and 308-443°C in nitrogen and air, respectively. Chromophore inclusion was confirmed by ultraviolet-visible (UV-vis) spectroscopy, which demonstrated tailorable photoluminescence (PL) in both the solution and the solid state by selective substitution of the chromophore. Polymer thin film PL studies revealed notable red-shifts compared with polymer solutions presumably attributable to aggregation in the solid state. Solution quantum yields of the polymers were comparable to those reported for the single chromophores used in this study.