Largely enhanced LED efficiency of carbazole-fluorene-silole copolymers by using TPBI hole blocking layer

A new series of soluble 3,6-carbazole-fluorene-silole copolymers (PCz-F-S) with M_w up to 52.1 kDa were synthesized by Suzuki coupling reactions. Chemical structures and optoelectronic properties of the copolymers were characterized by elemental analysis, NMR, UV absorption, cyclic voltammetry, photoluminescence (PL), and electroluminescence (EL) spectra. The main absorption peaks of solutions and films of the copolymers are at 354 nm and 347 nm, respectively, showing the combined contribution from the 3,6-carbazole and fluorene blocks. The silole absorption is at wavelength range between 400 nm and 500 nm. Compared with the solution absorption, largely decreased relative absorption of the silole to the 3,6-carbazole and fluorene blocks can be found for the films of the copolymers. The copolymers possess HOMO levels of around −5.36 eV, mainly from the contribution of 3,6-carbazole. Under excitation, the films of the copolymers show silole-dominated green emissions because of PL excitation energy transfer, with high absolute PL quantum yields up to 86%. EL devices with a configuration of ITO/PEDOT/PCz-F-S/Ba/Al only display a maximum external quantum efficiency of 0.48% whereas a device configuration of ITO/PEDOT/PCz-F-S/TPBI/Ba/Al with TPBI hole blocking layer greatly boosts the efficiency to 3.03% for a practical brightness of 236 cd/m². The improved EL efficiency suggests that more balanced charge injection and transport can be realized by inserting the TPBI hole blocking layer.     

New soluble rigid rod copolymers comprising alternating 2-amino-pyrimidine and phenylene repeat units: Syntheses, characterization, optical and electrochemical properties

A new type - π-conjugated copolymers of 2-amino-pyrimidine was prepared between 2-amino-4,6-diiodidepyrimidine and 1,4-dibromo-2,5-dialkoxybenzene by Sonogashira polycondensation. The structures of the copolymers were elucidated by FT-IR, ¹H NMR and ¹³C NMR, fluorescence spectroscopy, gel permeation chromatography, thermal analysis and element analysis. The derived polymers were soluble in common organic solvents and trifloroacetic acid and exhibited good thermal stability. They emitted green light under UV irradiation in solid state and blue or green light in solution phase, respectively. Electrochemical behavior of these new polymers depicted facile p-doping and good electron-transporting properties. These polymers displayed bathochromic shift when protonated with CH₃SO₃H acid in chloroform solutions or m-cresol solutions and the red-shifted peaks were observed from 490 nm to 652 nm. XRD patterns of copolymers showed that the intensity of peaks was enhanced with increasing alkyloxy chain length.     

Copolymerization of bis(chlorophthalimide)s with 2,5-dichlorobenzophenone catalyzed by NiBr2/PPh3/Zn

Copoly(phenylene-imide)s were synthesized by Ni(0)-catalyzed coupling of aromatic dichlorides containing imide structure and 2,5-dichlorobenzophenone. The route offered the flexibility of incorporating different ratios of benzophenone and imide groups in the polymer backbone in a controlled manner. The resulting copolymers exhibited high molecular weights (high inherent viscosity), and a combination of desirable properties such as good solubility in dipolar aprotic solvents and cresols, film-forming capability and good mechanical properties. Wide-angle X-ray diffractograms revealed that the polymers were amorphous. These copolymers had glass transition temperatures between 209 and 319 °C and 10% weight loss temperatures in the range of 502-543 °C in nitrogen atmosphere. The tough polymer films, obtained by casting from N-methylpyrrolidone solution, had a tensile strength range of 83-156 MPa and a tensile modulus range of 1.6-3.6 GPa.     

A novel conjugated polymer based on cyclopenta[def]phenanthrene backbone with spiro group

Poly(2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[def]phenanthrene)) (PCPP) is a stable blue light emitting conjugated polymer even after annealing at 150 °C or operation of the device in air. The spiro form of PCPP, poly(2,6-(3′,6′-bis(2-ethylhexyloxy)-4,4′-spirobi(4H-cyclopenta[def]phenanthrene))) (spiro-PCPP), has been synthesized by Yamamoto polymerization. The PL emission spectrum of the polymer in THF solution shows a maximum peak at 398 nm, nearly identical with that of PCPP. The PL spectrum of the polymer in the solid state exhibits a maximum peak at 451 nm, which is red-shifted over 50 nm from that of the solution, due to the inter-chain interaction of the polymers. The PL spectra of spiro-PCPP in the mixture of THF and MeOH from 9:1 to 3:7 ratios showed increasing peaks at 458 and 484 nm. With an increased ratio of the hydrophilic solvent (MeOH), the inter-chain interaction of the hydrophobic polymers was enhanced to show peaks at 458 and 484 nm. This phenomenon has the same tendency as compared to the PL spectrum in solid thin film state. The polymer LED with the configuration of ITO/PEDOT/spiro-PCPP/Ca:Al emitted light with maximum peaks at around 463 nm. The emission color of the spiro-PCPP device is sky blue with the CIE coordinates of (0.14, 0.15), which are close to those of the standard blue (0.14, 0.08).     

Time-resolved photoluminescence study of low-energy emission mechanisms in oligofluorene and polyfluorene films

We report time-resolved photoluminescence (PL) spectroscopy study of solutions and thin films of pure penta-fluorenes with varying alkyl side-chain structures. While no low-energy green emissions were observed in solutions, spin-cast and vacuum dried initial films exhibited low-energy emission in time-delayed PL spectra, centered at 490 nm, whose intensity varied strongly with the side-chain structure. In comparison, the films annealed at 170 °C in air showed nearly identical low-energy emission in time-delayed PL spectra, centered at 520 nm, regardless of the side-chain structures. Therefore, our experimental results obtained for pure penta-fluorenes provided clear evidence that the mechanism of the green emission of oligofluorene and polyfluorene films includes both the intermolecular aggregate/excimer formation, emitted around 490 nm, and fluorenone-type chemical defects, emitted around 520 nm.     

Electrospinning zwitterion-containing nanoscale acrylic fibers

Free radical copolymerization of n-butyl acrylate and a sulfobetaine methacrylamide derivative provided high molecular weight zwitterionic copolymers containing 6-13 mol% betaine functionality, and the electrospinning of low T_g zwitterionomers was explored for the first time. Copolymerizations were performed in dimethylsulfoxide (DMSO) rather than fluorinated solvents previously reported in the literature. Dynamic mechanical analysis of zwitterionomer films revealed biphasic morphology and featured a rubbery plateau and two distinct thermal transitions. Electrospinning from chloroform/ethanol (80/20 v/v) solutions at low concentrations between 2 and 7 wt% afforded nanoscale polymeric fibers with diameters near 100 nm. The presence of only 6 mol% zwitterion allowed the formation of low T_g, free-standing, non-woven mats, and we hypothesize that zwitterionic aggregation rather than chain entanglements facilitated electrospinning at these relatively low solution concentrations. To our knowledge, this is the first report of electrospun zwitterionic polymers and these non-woven membranes are expected to lead to new applications for sulfobetaine copolymers.     

Synthesis, characterization and photocross-linking of copolymers of furan and aliphatic hydroxyethylesters prepared by transesterification

Mild experimental conditions were applied to the synthesis of furan-aliphatic photoreactive copolymers by bulk transesterification, which called upon potassium carbonate as the catalyst, reaction times of about 30 h and temperatures ranging from 95 to 120 °C. The ensuing copolymers contained 3-10% of furan photoreactive monomer units, which absorbed at 308 nm, and had molecular weights of about 8000. They were semi-crystalline materials with glass transition temperatures of −51 to −62 °C and were stable up to 225 °C. The irradiation in the near-UV of concentrated solutions or thin films of these copolymers resulted in their cross-linking and suggested their possible use as photoresists, particularly in offset printing plates.     

Synthesis, thermal stability, light emission, and fluorescent photopatterning of poly(diphenylacetylene)s carrying naphthalene pendant groups

Naphthalene (Nap)-containing poly(diphenylacetylene)s with different spacer lengths (-{C₆H₅CC[C₆H₄O(CH₂)_mO-Nap]}_n-; P1(m), m = 4, 6, 8) are synthesized. The monomers are prepared by etherifications of 1,m-dibromoalkanes with 1-naphthol and 1-(4-hydroxy)phenyl-2-phenylacetylene and are polymerized by TaCl₅-n-Bu₄Sn and WCl₆-Ph₄Sn catalysts. Whereas the tantalum-based catalyst gives insoluble products in low yields, the tungsten-based catalyst furnishes soluble polymers with high molecular weights (M_w up to 5.0 × 10⁴) in satisfactory yields (up to 62%). The structures and properties of the polymers are characterized and evaluated by IR, NMR, TGA, UV, PL, and EL analyses. All the polymers are thermally stable: while the polymers lose 5% of their weights at ∼420 °C under nitrogen, no decreases in molecular weights are found after they have been annealed at 200 °C for 2 h in air. When their THF solutions are photoexcited, the polymers emit strong green lights with high efficiencies (up to 98%). No significant shifts in the photoluminescence spectra are observed when the polymers are cast into thin solid films, suggestive of little involvement of aggregative or excimeric emission. A multilayer EL device with a configuration of ITO/P1(8):PVK/BCP/Alq₃/LiF/Al is constructed, which emits a green light of 520 nm with a maximum external quantum efficiency of 0.16%. The spectral stability is outstanding: no recognizable change is observed in the EL spectrum when the device current is raised. Irradiation of a film of P1(8) through a mask photooxidizes and quenches the emission of the exposed regions, resulting in the formation of two-dimensional luminescent photopatterns.     

Syntheses, characterization, and energy transfer properties of benzothiadiazole-based hyperbranched polyfluorenes

A series of benzothiadiazole-based (BT) hyperbranched polyfluorene copolymers with various branching degrees (5-40%) were designed and synthesized. TGA and film annealing tests showed the substantial thermal stability of these highly branched polymers. The optical performance of the polymers in solutions and as films, and their electrochemical properties were characterized. The energy transfer (ET) processes in these hyperbranched conjugated polymers, both in solutions and in the solid state, were also investigated. With the change of the solution concentration and the branching degree, the energy transfer efficiency of the polymers varied in solutions and the main photoluminescence (PL) peaks changed from blue to green region. As films, only green light emitted from BT units. In addition, the PL efficiency of the films decreased dramatically with the increase of branching degrees. All these features demonstrated that highly branched structure would effectively impede the intra- and interchain energy migration, especially in solutions, and remarkably influence the ET process in the solid state, which resulted in low PL efficiency.     

Electrochemical and optical properties of new soluble dithienylpyrroles based on azo dyes

Two dithienylpyrroles based on azo dyes, namely 2,5′-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB2) and 2,5′-dimethyloxy-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB3), were synthesized and their corresponding polymers (PSNS-AB2 and PSNS-AB3) were successfully obtained via electropolymerization. The monomers have lower oxidation potentials (0.75 V and 0.80 V vs. Ag/AgCl for SNS-AB2 and SNS-AB3, respectively) when compared to their analogous. Both monomers exhibited photoisomerism properties under irradiation at 360 nm. During the irradiation process, for example, the color of SNS-AB3 changes from yellow to greenish yellow. The electroactive polymer films have well defined and reversible redox couples with a good cycle stability in both aqueous and organic solutions. The polymer films also exhibited electrochromic behaviors; color changes from yellowish green to dark green for the PSNS-AB2 (λ_max = 435 nm and E_g = 2.31 eV) and from mustard color to green for PSNS-AB3 (λ_max = 430 nm and E_g = 2.34 eV). Furthermore, the soluble polymers demonstrated different hues of yellow and green colors.     

Synthesis and photophysics of new highly luminescent poly(alkylthiophene) derivatives with pyridine in the backbone

Starting from 2,6-bis-(3-octylthiophene-2yl)-pyridine, two new poly(alkylthiophene) derivatives, POTPyOT and POTPy, containing pyridine in the backbone were prepared from nickel(0)-mediated Stille coupling or by palladium-catalyzed Yamamoto coupling. These polymers exhibited good solubility in common organic solvents, thermal stability up to 400 °C, and facile film formation. They were amorphous and give strong luminescence both in CHCl₃ solution and solid state film. The polymers emitted blue light in solution with photoluminescence (PL) emission maximum at 420-484 nm and green light with PL emission maximum at 500-514 nm in thin films. These polymers showed a reversible redox reaction at potential from 0 to 1.3 V (vs. SCE). Nevertheless, the reduced form of the polymer was very unstable; it decomposed in the presence of oxygen or water. The emission and UV-vis absorption of the polymer were influenced by the solvent polarity, protonation, and acid-base treatment. These may be the results of the stabilization of the polar excited state by solvation and the change of the conformation in polymer backbone. Electroluminescence (EL) was achieved from a single-layer PLED with the configuration of ITO/POTPyOT/Al. The turn-on voltage of the device is 10 V and the λ_max (550 nm) of the EL is voltage independent.     

Theoretical studies on the electronic and optical properties of two thiophene-fluorene based π-conjugated copolymers

The low PL quantum efficiency, typically 1-3%, in solid film, limits the application of polythiophene and derivatives (PTs) in PLEDs. The six-member aromatic rings polyfluorenes (PFs) with higher PL efficiencies have been introduced into the backbone of PTs, in an effort to develop highly efficient, desirable charge carrier transporting and low energy gap thiophene-fluorene based light-emitting polymers. In this contribution, quantum-chemical techniques are employed to study two fluorene-thiophene incorporated π-conjugated polymers, namely, poly((5,5-E-α-(2-thienyl)methylene)-2-thiopheneacetonitrile)-alt-2,7-(9,9-dimethylfluorene) (PFTCNVT) and poly((5,5″-(3′,4′-dimethyl-2,2′;5′,2″-terthiophene1′,1′-dioxide))-alt-2,7-(9,9-dimethylfluorene)) (PFTORT). Density functional theory (DFT) and time-dependent DFT approaches are employed to study the neutral molecules, positive and negative ions, the IPs and EAs, HOMO-LUMO gaps (Δ_H-L), as well as the lowest excitation energies (E_gs). It is interesting to note that the two copolymers PFTCNVT and PFTORT are superior to the properties of pristine polyfluorene (PF) and polythiophene (PT). In addition to the improved PL efficiency, they still presented lower energy-gap comparable to PTs. Furthermore, the LUMO energies lower about 1.4 eV and thus the EAs increase around 1.4 eV in PFTCNVT and PFTORT compared with PFs, suggesting the significant improved electron-accepting and transporting abilities in the two copolymers. These properties can be explained by the presence of more electron-accepting thiophene units in the repeated unit of the copolymers and the more planar conformations in the two copolymers under study.     

Synthesis and characterization of two shape-memory polymers containing short aramid hard segments and poly(ε-caprolactone) soft segments

A number of segmented copolymers were synthesized by reacting 4-aminobenzoyl end-functionalized poly(ε-caprolactone)s of M_n 2000, 3000 and 4000 g mol⁻¹ with three aromatic diacid dichlorides in the presence of chlorotrimethylsilane. Polymer purity, molar mass, thermal and mechanical properties were characterized by NMR, MALDI-TOF mass spectrometry, GPC, DSC, and DMTA. Promising shape-memory properties were observed for two polymers that contained comparatively short, semicrystalline poly(ε-caprolactone) soft segments of molecular weight 3000 g mol⁻¹ and either terephthalamide or 2,6-naphthalenedicarboxyamide hard segments. Cast films of these polymers were soft and elastomer-like at room temperature. Loading could be conveniently achieved by cold-drawing at room temperature and strain recovery took place upon heating above the melting temperature of the soft segment (35 °C). Cast films reached uniform deformation properties with strain recovery rates as high as 99% and strain fixity values of 78% after passing through only one or two training cycles.     

Surfactant-free artificial latexes from modified styrene-maleic anhydride (SMA) copolymers

We describe the preparation of surfactant-free artificial latexes on the basis of poly(styrene-alt-maleic anhydride) (SMA) copolymers. The SMA copolymers were first partially alkyl-imidized and then partially ammonolyzed in acetone. Upon adding to water and after the removal of acetone, the modified copolymers formed stable latexes, with a diameter of ∼150 nm and a PDI < 0.2. In the absence of alkyl groups the particles became completely soluble in water after a few days. The latexes from the partially alkyl-imidized polymer were found to remain stable at pH > 2. The incorporation of alkyl groups into the copolymers significantly lowered the T_g of the polymer from 150 to 75 °C, depending on the amount of alkylamines added. It was found that the molecular weight as well as the molar mass distribution of the SMA polymers did not show major effects on the properties of the artificial latexes.     

Blue light-emitting diodes from mesogen-jacketed polymers containing oxadiazole units

A series of novel mesogen-jacketed polymers, poly{2,5-bis[(5-tert-butylphenyl)-1,3,4-oxadiazole]styrene} (P-Ct) and poly{2,5-bis[(5-alkoxyl-phenyl)-1,3,4-oxadiazole]styrene} (P-OCn, n is the number of carbons in the alkoxyl groups, n = 6, 8, 10, 12, 14), were incorporated into polymer light-emitting device as the light-emitting layers. All of the polymers had excellent solubility in common organic solvents. The UV and PL spectra for P-Ct were 312 and 400 nm while for P-OCn they were around 328 and 420 nm in the film. There was no red shift in the PL spectrum of P-Ct after heat treatment which maybe related to the jacketed structure. All of the polymers showed high PL quantum yields in THF solution. From the cyclic voltammetry measurement at room temperature, HOMO levels of the polymers were varied from −5.66 to −6.12 eV, LUMO levels were varied from −2.45 to −2.81 eV. Furthermore, the influence of the alkoxyl lengths in four different device configurations was compared. For the device configuration c: ITO/PVK/P-OC8/Ca/Ag, the maximum luminance and maximum external quantum efficiency were obtained for P-OC8 which maybe related to the easier electron injection and transport. Efficiency of P-OC8 was not improved with device d which proved the electron transporting characteristics of P-OC8.     

Synthesis and electroluminescent properties of copolymers based on PPV with fluoro groups in vinylene units

New electroluminescent copolymers with fluoro groups in vinylene unit, poly(2-ethylhexyloxy-5-methoxy-p-phenylenevinylene-co-2-dimethyloctylsilyl-p-phenylenedifluorovinylene) (MEH-PPV-co-DMOS-PPDFV) and poly(2-dimethyloctylsilyl-p-phenylenevinylene-co-2-dimethyloctylsilyl-p-phenylenedifluorovinylene) (DMOS-PPV-co-DMOS-PPDFV), have been synthesized by the Gilch polymerization. The fluoro groups were introduced on vinylene units to increase the electron affinity of the copolymers. In both types of the copolymers, the band gaps were increasing with higher ratio of DMOS-PPDFV. As compared to the PL spectra in solution state, PL spectra in solid state and EL spectra of both types of copolymers showed red shifted and broad peaks caused by the aggregation. The polymer LEDs of MEH-PPV-co-DMOS-PPDFVs emit light with maximum peaks at around 538-577 nm. By adjusting the feed ratios of DMOS-PPDFV in the copolymers, we could tune the emission colors from orange yellow to green. DMOS-PPV-co-DMOS-PPDFVs showed the maximum EL peaks at about 514-543 nm. DMOS-PPV-co-DMOS-PPDFV with 1:9 feed ratio showed the highest luminescence efficiency of 1.31 lm/W.     

Synthesis and characterization of amphiphilic block copolymers from poly(ethylene glycol)methyl ether and 4-methyl-?-caprolactone or 4-phenyl-?-caprolactone

MPEG-b-PMCL and MPEG-b-PBCL diblock copolymers were synthesized by ring-opening polymerization of 4-methyl-?-caprolactone (MCL) or 4-phenyl-?-caprolactone (BCL) using monomethoxy poly(ethylene glycol) (MPEG, M_n = 550 or 2000 g mol⁻¹) as the macroinitiator and SnOct₂ as the catalyst. These copolymers were characterized by differential scanning calorimetry (DSC), ¹H NMR, ¹³C NMR, and gel permeation chromatography. The thermal properties (T_g and T_m) of the diblock copolymers depend on the composition of polymers. When larger amount of MCL or BCL was incorporated into the macromolecular backbone there was an increase in T_g. Their micellar characteristics in the aqueous phase were investigated by fluorescence spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). The block copolymers formed micelles in the aqueous phase with critical micelle concentrations (CMCs) in the range of 0.5-2.9 mg L⁻¹, depending on the composition of polymers. The lengths of hydrophilic segment influence the shape of micelle. The mean hydrodynamic diameters of micelles from DLS were in the range of 70-140 nm. The drug entrapment efficiency and the drug-loading content of micelles depending on the composition of block polymers were described.     

The evolution behavior of microstructures and optical properties of ZnO films using a Ti buffer layer

ZnO thin films without and with Ti buffer layer were prepared on Si and glass substrates by radio frequency (RF) magnetron sputtering. The effects of Ti buffer layer with different sputtering time on the microstructure and optical properties of ZnO thin films had been investigated by means of X-ray diffraction (XRD), energy dispersive spectrometer, X-fluorescence spectrophotometer and ultraviolet–visible spectrophotometer. The XRD results showed that the full-width at half-maximum (FWHM) for the ZnO (002) diffraction peak gradually decreased with the increase of sputtering time of Ti buffer layer, indicating that the crystalline quality of ZnO thin films was improved. The UV peak located at 390 nm, two blue peaks located at about 435 and 487 nm, two green peaks located at about 525 and 560 nm were observed from PL spectra. The PL spectra showed that the strongest blue light emission of ZnO films was obtained from Ti buffer layer with the sputtering time of 10 min. Meanwhile, the origins of the emission peaks were discussed through the Gaussian deconvolution. We also studied the optical band gaps.     

Synthesis and characterization of partly fluorinated poly(phthalazinone ether)s crosslinked by allyl group for passive optical waveguides

It is necessary to introduce cross-linkable groups onto polymer chains as the processability and thermal stability of the polymers for passive waveguide device applications are very dependent on their cross-linking capabilities. Herein a series of novel cross-linkable allyl-containing fluorinated poly(phthalazinone ether)s (Allyl-FPPEs) have been prepared by a modified polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), decafluorobiphenyl (DFBP), 4,4′-(hexafluoroisopropylidene)diphenol (6F-BPA), and 3,3′-diallyl-4,4′-dihydroxybiphenyl (DA-DHBP) for optical waveguide applications. The obtained random polymers were characterized by FT-IR, NMR and GPC. The resulting polymers having good solubility in polar organic solvents at room temperature, can be easily spin-coated into thin films with attracting optical quality, good thermal stabilities (the temperatures of 1% mass-loss after curing: 455-503 °C), and high glass transition temperatures (T_gs: 167-251 °C) which could further increase by about 20 °C after thermal cross-linking. The crosslinked polymer films exhibit good optical properties. By adjusting the feed ratio of the reactants, the refractive indices of TE and TM modes (at 1550 nm) could be well controlled in the range of 1.4998-1.5618 and 1.4954-1.5520, respectively. The optical losses of the crosslinked polymers possess rather low values, less than 0.3 dB/cm at 1550 nm.     

Synthesis, characterization, and properties of chain terminated polyhedral oligomeric silsesquioxane-functionalized perfluorocyclobutyl aryl ether copolymers

A new class of perfluorocyclobutyl (PFCB) polymers covalently functionalized with polyhedral oligomeric silsesquioxane (POSS) is presented. Three discreetly functionalized POSS monomers possessing thermally reactive trifluorovinyl aryl ether (TFVE) were prepared in good yields. The POSS TFVE monomers were prepared by initial corner-capping of cyclopentyl (-C₅H₉), iso-butyl (-CH₂CH(CH₃)₂), or trifluoropropyl (-CH₂CH₂CF₃) functionalized POSS trisilanols with acetoxyethyltrichlorosilane followed by sequential acid-catalyzed deprotection and coupling with 4-(trifluorovinyloxy)benzoic acid. TFVE-functionalized POSS monomers were thermally polymerized with 4,4′-bis(4-trifluorovinyloxy)biphenyl or 2,2-bis(4-trifluorovinyloxybiphenyl)-1,1,1,3,3,3-hexafluoropropane monomers via a condensate-free, [2 + 2] step-growth polymerization. The polymerization afforded solution processable PFCB polymers with POSS macromer installed on the polymer chain ends. POSS monomers and their corresponding copolymers were characterized by ¹H, ¹³C, ¹⁹F, and ²⁹Si NMR, GPC, ATR-FTIR, and elemental combustion analysis. GPC trace analysis showed agreeable number-average molecular weight for various weight percent of cyclopentyl or iso-butyl and trifluoropropyl chain terminated POSS PFCB copolymers. DSC analysis showed the introduction of increasing POSS weight percent in the endcapped PFCB copolymers lowers the glass transition temperatures as high as 31 °C. On the other hand, the trifluoropropyl POSS endcapped PFCB polymer glass transition temperature was unaffected when copolymerized with the more fluorinated 2,2-bis(4-trifluorovinyloxybiphenyl)-1,1,1,3,3,3-hexafluoropropane monomer. TGA analysis of POSS PFCB copolymers showed step-wise decomposition of copolymers resulting from the initial degradation of the POSS cages at 297-355 °C in nitrogen and air which was confirmed by pyrolysis coupled with GC-MS. This initial weight loss was proportional to the weight percent of POSS incorporated into the polymer. The balance of decomposition was observed at 450-563 °C in nitrogen and air which is higher than the PFCB homopolymers in most cases. Polymer surface characterization was performed on spin cast transparent, flexible films. These composite films exhibited good POSS dispersion within the matrix PFCB polymer as was shown by TEM analysis.