Synthesis of Long-Chain-Branched (LCB) Polysulfones for 

Multifunctional Transport Membranes 

by Andrew J. Duncan, Donald J. Leo, Timothy E. Long, 

and James F. Snyder 

ARL-TR-5284 September 2010 

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Army Research Laboratory 

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ARL-TR-5284 September 2010 

Synthesis of Long-Chain-Branched (LCB) Polysulfones for 

Multifunctional Transport Membranes 

Andrew J. Duncan, Donald J. Leo, and Timothy E. Long 

Virginia Polytechnic Institute and State University 

James F. Snyder 

Weapons and Materials Research Directorate, ARL 

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Synthesis of Long-Chain-Branched (LCB) Polysulfones for Multifunctional 

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Andrew J. Duncan,* Donald J. Leo,* Timothy E. Long,* and James F. Snyder 

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The Macromolecules and Interfaces Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 

14. ABSTRACT 

Long-chain-branched (LCB) polysulfones were synthesized for potential application as multifunctional ion-transport 

membranes. Combination of bulky and rigid monomer units with controlled levels of branching is proposed as a method to 

increase free volume of the polymer matrix. Increases in free volume may allow for improved ion transport decoupled from the 

segmental motion of the polymer backbone, especially in these high glass transition temperature materials. Increased transport 

in glassy materials enables multifunctional applications that require ion transport and structural rigidity. The series of novel 

polymers was characterized for chemical structure, thermal transitions, and molecular weight. Ionic conductivity was tested for

films cast in the presence of two lithium salts. 

15. SUBJECT TERMS

branched polymer electrolyte synthesis 

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James F. Snyder 

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iii

Contents 

List of Figures iv

1. Introduction 1

2. Experimental Materials and Methods 2

3. Results and Discussion 4

4. Summary 11

5. References 12

List of Symbols, Abbreviations, and Acronyms 14

Distribution List 16 
iv

List of Figures 

Figure 1. A2 + B2 + B3 synthesis of long-chain-branched PSF-PO. ...............................................5

Figure 2. (i) LIN-PSF-PO and (ii) LCB-0.4-PSF-PO analyzed with FTIR in (a) DMAc 

solution with (b) K2CO3 and (c) DHDPS for disappearance of the aromatic carbonfluorine bond (664 cm-1) from the monomers (d) BFP3O and (e) TFPPO reacting to form 

the polymers (f) LIN-PSF-PO and (g) LCB-0.4-PSF-PO (alphanumeric characters 

indicate each individual curve). .................................................................................................6

Figure 3. 1H NMR spectra overlaid for the series of linear and branched PSF-PO. .......................7

Figure 4. SEC traces and molecular weight results for LIN-PSF-PO (maroon) and LCB-PSFPO (mol % TFPPO: 0.2 = green, 0.4 = light blue, 0.6 = dark blue). ........................................8

Figure 5. DSC heat capacity traces and Tg for LIN-PSF-PO (blue) and LCB-PSF-PO (mol % 

TFPPO: 0.2 = black, 0.4 = red, 0.6 = green). ............................................................................9

Figure 6. DMA storage modulus and tan delta signals versus temperature showing Tg and 

sub-Tg transitions for LIN PSF-PO. .........................................................................................10

Figure 7. Combined Bode plot (|Z|, phase) for LIN-PSF-PO cast (blue: diamond, X) in the 

presence of Li+

 Tf- (red: square, asterisk) or Li+ Bim- (green, up triangle, down triangle) 

against an empty background (black: circle, cross). ...............................................................11
1

1. Introduction 

Increasing numbers of technologies are based on the idea of harnessing charge transport for 

useful processes, such as energy harvesting, actuation, sensing, and permselectivity (1). 

Although much progress exists based on perfluorosulfonated platforms (Nafion, σ ≈ 10-1 – 10-2

S/cm) new and more complicated parameters arise as applications require multifunctionality in 

engineering materials (2). For instance, in addition to using lightweight, durable, stable, high 

conductivity proton-exchange membranes in a fuel cell, it may be desirable to have the energy 

source bear load and operate as a structural installment. The most prevalent class of materials 

potentially capable of such a tradeoff are rubbery “salt-in-polymer” electrolytes that employ 

polymer segmental motion for transport of free ions from co-dissolved salts (3, 4). Recently, 

Snyder et al. synthesized a series of “salt-in-polymer” electrolytes from various vinyl-ester 

resins, poly(ethylene glycol)s (PEO), and lithium trifluoromethanesulfonate (Li-Tf) (5). Various 

polymer topologies and other parameters were investigated, although none significantly varied 

the inverse relationship between mechanical stiffness and ionic conductivity. Another promising 

material class is conductive ionic glasses that demonstrate a high dielectric constant such that ion 

hopping through lattice defects provides sufficient conductivity in the glassy state (6). Imrie et 

al. did not investigate branching, but did show that liquid crystalline polyether sidegroups 

prevented packing of PEO sections of the main chain and resulted in increased conductivity in 

the glassy state (7). The multifunctional requirement starkly reflects the difficulty of using 

materials that display low ambient temperature modulus (especially when hydrated), including 

PEO and Nafion, or consideration of the significant decrease in ionic conductivity with the 

removal of the hydrating diluent/electrolyte. An overall approach to achieve both goals is to 

decouple ion transport from the segmental motion of the polymer through macromolecules 

designed to incorporate polar, bulky, irregular, rigid monomers into the backbone (8). 

An A2 + B2 +B3 polycondensation route is chosen to build upon existing methods and 

understanding of polymer branching (9). As reviewed, very few investigations exist concerning 

the effect of branching on decoupled ion transport in glassy, low humidity single-ion conductors. 

The chosen matrix of materials includes linear and long-chain-branched polysulfone phosphine 

oxides (LCB-PSF-PO). The use of polar B2 and B3 monomers will aid in the complexation of 

mobile ions from the imbibed salt within the matrix for charge stabilization and a decrease in the 

activation energy for ion hopping. The investigation of decoupled ion transport in such materials 

is also interesting for reasons of its implications in the electromechanical transducer field. 

Increases in ion transport without diluents or charges bound to the backbone are likely to 

augment ionic polymer transducer (IPT) performance through additive increases in ionic 

conductivity when introduced into ionomer composition and construction of the IPT composite. 

 

Nafion is a registered trademark of DuPont. 
2

IPTs also do not require the same modulus levels as multifunctional batteries and fuel cells, thus 

providing a potential application for high conductivity composites that fall short of the structural 

target. 

Previous systems demonstrated with PEO that three to four etheric oxygens serve to complex a 

single monovalent cation (10). Inclusion of branching into the system anticipates the difficult 

balance between establishing rigidity in the material while increasing intermolecular and 

intramolecular free volume for the purpose of complexation. To further extend the free volume 

effect, all chosen monomers are bulky in addition to their rigid nature, placing at least four 

aromatic rings in the backbone of each repeat unit. The monomers were recrystallized for purity 

before examining their characteristic spectra in comparison to the final polymers with Fourier 

transform infrared spectroscopy (FTIR). The final polymers are characterized with nuclear 

magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), 

thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic 

mechanical analysis (DMA). Films cast in the presence of Li-Tf and lithium 

bis(trifluoromethane)sulfonimide (Li-Bim) were also characterized for their ionic conductivity 

with electrical impedance spectroscopy (EIS). 

2. Experimental Materials and Methods 

4,4’-dihydroxydiphenylsulfone ([DHDPS], Alfa Aesar, 99.9%) was purified by dissolving in a 

5% sodium bicarbonate solution and precipitation through adjustment of the pH to a value of 5 

with concentrated hydrochloric acid. The crystals were redissolved in aqueous methanol (50%) 

for a final precipitation before drying in vacuo at 100 °C for 24 h (11). DHDPS was otherwise 

used as received from monomer grade material. Bis(4-fluorophenyl)phenylphosphine oxide 

([BFP3O], Aldrich, 97%) was purified by recrystallization from toluene in triplicate. Anhydrous 

potassium carbonate (K2CO3) was purchased from Fluka and dried in vacuo at 120 °C for 24 h 1-

bromo-4-fluorobenzene (99%). Magnesium, and phosphorous trichloride (99.9+ %) were 

purchased from Aldrich and used as received without further purification to synthesize the B3

monomer, tris(4-fluorophenyl) phosphine oxide (TFPPO), according to previously reported 

procedures (12). Further supply of TFPPO was synthesized through oxidation of tris(4-

fluorophenyl) phosphine (Aldrich, purum, 98.0% pure) with hydrogen peroxide (30 weightpercent). Dimethylacetamide ([DMAc], Aldrich, anhydrous, 99.8% pure) was stored over 

molecular sieves under a nitrogen atmosphere until use. Toluene (Aldrich, 98% pure) was dried 

using a fully contained solvent purification system and stored over molecular sieves under a 

nitrogen atmosphere until use. 

DHDPS, BFP3O, TFPPO, K2CO3, DMAc, and toluene (2:1 v/v DMAc to toluene) were charged 

in a 100 ml three-neck, round-bottom flask at approximately 20 weight-percent solids in DMAc. 

The reaction setup was equipped with an overhead mechanical stirrer, a dry nitrogen inlet (with 
3

condenser), and a Dean-Stark trap attached to a reflux condenser. The system was purged with 

nitrogen for 30 min before immersion in a constant temperature bath at 145 °C for 

4 h, allowing reflux to remove the water/toluene azeotrope from the reaction mixture. Dropwise 

removal of residual water/toluene was performed during the temperature ramp to 165 °C. The 

reaction at 165 °C was allowed to proceed for approximately 110 h. The reaction solution was 

allowed to cool to ambient conditions without stirring while remaining under a nitrogen 

atmosphere. The reaction mixture was directly vacuum filtered with filter paper to remove the 

salt residue condensed by the reaction. The resulting polymer was precipitated into stirring 

deionized water. The polymers were collected by vacuum filtration and dried in vacuo at 250 °C 

for 1 h followed by a slow cooling under reduced pressure to room temperature. The polymers 

resulting from this synthesis are classified as linear (LIN) and long-chain-branched (LCB)-X 

where X is the mol percent of TFPPO incorporated into the polymer to enable branching. 

The reaction solution and solutions of the final polymers were analyzed for disappearance of the 

aromatic carbon-fluorine bond on BFP3O and TFPPO with an ASI ReactIR 4000 in-situ FTIR 

Spectrometer. NMR analysis of the hydrogen (1

H) and carbon (13C) nuclei in long-chainbranched polysulfones were performed using a Bruker 600 MHz spectrometer at ambient 

temperature in deuterated dimethylsulfoxide. Absolute molecular weights and polydispersity 

indices (PDI) were determined by SEC in a Waters system having three in-line Polymer 

Laboratories PLgel 5 m MIXED-C columns with an autosampler. Detection is performed 

through a Waters 2414 Refractive Index detector, a Viscotek 270 Dual Detector viscometer, and 

a Wyatt Technologies miniDAWN multiangle laser light scattering (MALLS) detector in Nmethyl pyrrolidone (NMP) at 50 °C. Thermogravimetric analysis was performed with a TA 

HighRes-2950 instrument at 10 °C/min under a nitrogen flow. Sub-ambient and high 

temperature thermal transitions were detected and analyzed with a TA Q1000 differential 

scanning calorimeter at 10 °C/min under a nitrogen flow. Transitions were determined from the 

second heat cycle. Membranes were cast from 10 weight-percent solutions in DMAc on level 

glass substrates. Casting was performed at approximately 40 °C under a heat lamp for 24 h. 

Sub-ambient and high temperature DMA was performed with a TA Q800 instrument at 10 

°C/min under a nitrogen flow. Electrical properties of the polysulfone-phosphine oxide (PSFPO) membranes were evaluated through EIS with an Autolab PGSTAT12 

Potentiostat/Galvanostat and FRA2 Impedance Module over a frequency range of 1 MHz – 

0.1 Hz. The instrument was operated in potentiostatic mode to apply a single 100 mV rms sine 

wave while measuring the complex impedance response of the sample. A custom fixture aligned 

two parallel rectangular brass rods at a defined separation of 0.3 cm to allow for in-plane 

impedance measurements with a maximum sample length of 3 cm. A load placed on top of the 

fixture ensured consistent and constant contact between the surface of the sample and the 

electrodes. All measurements were performed inside a custom-built Faraday cage and a humidity 

chamber at room temperature with controlled relative humidity of 42 ± 2%. Ionic conductivity 

values (σ, S/cm) were calculated with the equation: 
4

R l w

t

    (1) 

based on the in-plane two-point measurement geometry and an estimate of the bulk membrane 

resistance (R, Ohm) where t (cm) is the sample thickness, l (cm) is the sample length, and w (cm) 

is the sample width. The Autolab Frequency Response Analysis (FRA) software was employed 

to fit a circle to the kinetic portion of the complex impedance data (Nyquist plot) to extrapolate 

the bulk membrane resistance as the low frequency x-intercept where the imaginary component 

of the impedance equals zero. After mounting each sample, the impedance was measured to 

detect equilibration of the membrane with the chamber humidity. Measurements for calculation 

of the conductivity were not recorded until the change in impedance with time was less than 

0.75% per minute. At this point, three to five impedance measurements were performed 

sequentially. The average value of the bulk impedance was used to calculate the membrane 

conductivity. One standard deviation typically represented no more than 10% error from the 

average value. Error was significantly smaller for less hygroscopic membranes. 

3. Results and Discussion 

Following their respective purification steps, the DHDPS (A2), BFP3O (B2), and TFPPO (B3) 

were confirmed to be of suitable monomer grade purity for step-growth reactions by both thin 

layer chromatography and elemental analysis. The monomers were combined, as shown in 

figure 1, using 0, 0.2, 0.4, and 0.6 mol percent of TFPPO to facilitate the polymerization of longchain branches from the backbone. Long reaction times were employed initially due to the 

expected decrease in reactivity of DHDPS compared to other bisphenols that have been 

demonstrated for polysulfones. Indicators for molecular weight development were mainly 

changes in viscosity of the reaction solution during the first screenings of the reaction. 
5

HO OH

O

O

S

1. toluene / DMAc

K2CO3

145 °C, 4 h

2. DMAc 

170 °C, 48 h

x

+ 2KF

+ +

1-x

(x) (1-x)

+ + H2O CO2

O

F P F

F

O

F P F

O

O

O O

O

O

O O S

O

O

S

O

P

O

P

O S O

P O

1-x

Figure 1. A2 + B2 + B3 synthesis of long-chain-branched PSF-PO. 

In-situ FTIR trials were planned to monitor molecular weight development in the backbone and 

branches due to condensation of the carbon-fluorine functionality on the aryl ring (carbonfluorine bond at ~664 cm-1) of BFP3O and TFPPO to the ester bond on reaction with DHDPS 

(13). Not only does this technique allow for estimation of sufficient time to reach near 100% 

conversion, but it also provides for observation of the limitations of converting the linear branch 

unit on the PSF-PO backbone to a dendritic one, namely the genus of a long-chain branch. 

However, the study only reached initial observations of the reaction solution, including all 

monomers, solvent, and reactants. Use of the FTIR also allowed for analysis solution spectra for 

linear polysulfone phosphine oxide (LIN-PSF-PO) and LCB 0.4 PSF-PO polymers, which are 

shown in figure 2 (i) and (ii) respectively. Comparison between those spectra of monomers and 

polymers in DMAc confirmed that the carbon-fluorine bond decreased significantly in the 

polymer and is a viable candidate to track with realtime in-situ FTIR. 
6

Absorbance

(d)

(c)

(b)

(f)

(a)

Absorbance

(e) (d)

(c)

(b)

(g)

(a)

(i)

(ii)

Figure 2. (i) LIN-PSF-PO and (ii) LCB-0.4-PSF-PO analyzed with FTIR in (a) DMAc solution with (b) 

K2CO3 and (c) DHDPS for disappearance of the aromatic carbon-fluorine bond (664 cm-1) from 

the monomers (d) BFP3O and (e) TFPPO reacting to form the polymers (f) LIN-PSF-PO and (g) 

LCB-0.4-PSF-PO (alphanumeric characters indicate each individual curve). 

The structure of the resulting long-chain-branched polymers (and linear analogue) was 

confirmed with shift assignment and integration of the corresponding peaks in 1

H NMR and 13C 

NMR. A spectral comparison of the linear and branched polymers is provided in figure 3. The 

protons on the aromatic rings immediately adjacent to the sulfone display a shift at 8 ppm. 

Similarly located protons on the aromatic rings bonded to the phosphine oxide display a peak at 
7

7.65 ppm. All aromatic protons adjacent to the etheric oxygen show a peak shift of 7.23 ppm. 

The small peak at 7.55 ppm is associated with the two opposing aromatic protons furthest from 

the backbone in BFP3O. Fluorine (19F) NMR was planned to observe residual endgroups in the 

linear polymers, as well as the linear and terminal units from partially reacted TFPPO in the 

long-chain-branched polymers. The full distribution of branching efficiency, conversion to 

dendritic units, would also be visible in phosphorus (31P) NMR with increasing inclusion of the 

B3 unit and molecular weight. These characterizations were not available at the time of analysis 

and are yet to be completed. 

LIN-PSF-PO

LCB-0.2-PSF-PO

LCB-0.4-PSF-PO

LCB-0.6-PSF-PO

Figure 3. 1H NMR spectra overlaid for the series of linear and branched PSF-PO. 

Absolute molecular weights resulting from the A2 + B2 + B3 reaction, as determined from the 

MALLS traces given by SEC analysis, are shown in figure 4. The curves are color coded to the 

molecular weight data. Curves not identified were other synthetic iterations that do not 

contribute to the discussion here. Development of molecular weight in the linear system is more 

easily achieved, almost by two times the molecular weight of the branched polysulfones. To 

qualify as long-chain branches, each branch must have an individual molecular weight greater 

than that of the entanglement molecular weight for the linear polymer. Although the degree of 

branching is not yet confirmed from NMR, the multi-modal peaks in SEC are typical of branched 

polymer elution. Due to the low level of total branching associated with long-chain branches, 

the polydispersity index is approximately equal to the linear sample and does not show the high 

values normally observed for hyperbranched systems (14). Overall, the final polymer molecular 
8

weights from reactions with identical conditions may indicate that the development of molecular 

weight from the TFPPO (B3) monomers is hindered as compared to reaction with the chemically 

similar BFP3O (B2) monomer. 

PSF-PO Mn (g/mol) Mw (g/mol) PDI

LIN 38 000 73 000 1.89

LCB-0.2 14 000 23 000 1.65

LCB-0.4 22 000 34 000 1.56

LCB-0.6 14 000 24 000 1.73

Figure 4. SEC traces and molecular weight results for LIN-PSF-PO (maroon) and LCB-PSF-PO (mol % 

TFPPO: 0.2 = green, 0.4 = light blue, 0.6 = dark blue). 

The thermal stability of the polymer series was investigated with TGA. Very little difference in 

degradation temperatures (5% weight loss, Td5%) is observed between the linear and branched 

samples or due to the level of branching. The average Td5% is ~460 °C and proceeds quickly 

through two steps to a significant char yield (~20%) at 800 °C. The TGA test also reveals that 

even after drying these materials are very hygroscopic, likely due to the high concentration of 

polar groups in the backbone. The thermal transitions were initially observed with DSC. As 

expected, the effect of introducing low levels of long-chain branching has very little effect on the 

glass transition temperature (Tg) in comparison to the linear material. Based upon second heat 

measurements these fully amorphous polymers display a Tg between 231–236 °C for the linear 

and branched samples (figure 5). However, of greater interest is the comparison between the 

glass transition regions of the first and second heats. Although the speed of the cooling ramp 

associated with drying/annealing was not measured, the cool was not forced and is assumed to be 

much slower than the 10 °C cooling cycle programmed for DSC. Whereas the first heating cycle 

does not display any physical aging post-Tg, the second heat does display a maximum post-Tg, 

indicative of free volume isolated within the polymer during the cooling cycle (15). This 

characteristic is likely due to the use of rigid, bulky monomers that restrict the polymer from 

achieving its thermodynamic equilibrium during transition from the rubbery to the glassy state. 
9

**curves shifted vertically for clarity**

0.0581J/g/°C

0.0563J/g/°C

0.0673J/g/°C

0.0626J/g/°C

1.2

1.4

1.6

1.8

2.0

2.2

2.4

Heat Capacity (J/g/°C)

160 180 200 220 240 260 280 300

Temperature (°C)

––––––– LIN-PSF-PO

– – – – LCB-0.2-PSF-PO

––––– · LCB-0.4-PSF-PO

––– – – LCB-0.6-PSF-PO

Universal V3.9A TA In

PSF-PO Tg (oC)

LIN 234

LCB-0.2 231

LCB-0.4 233

LCB-0.6 236

Figure 5. DSC heat capacity traces and Tg for LIN-PSF-PO (blue) and LCB-PSF-PO (mol % TFPPO: 0.2 

= black, 0.4 = red, 0.6 = green). 

The dynamic mechanical performance of these LIN-PSF-POs and LCB-PSF-POs was 

determined with DMA across a wide range of temperature (figure 6). It should be noted that 

casting films of the long-chain-branched polymers was severely limited, likely due to insufficient 

development of molecular weight. Tough films were characteristic for LIN-PSF-PO while the 

LCB series was very brittle. The linear film displayed a storage modulus of approximately 1 

GPa in the glassy state across a wide range of temperature, which may be useful for structural 

applications. The appearance of the glass transition agrees with the range observed in DSC. 

Furthermore, at subambient temperature peaks are observed in the tan delta signal. The peak at 

10 °C is likely the detection of free water melting in the hygroscopic polymer matrix. The lower 

beta transition at -100 °C is attributed to the aromatic rings of the backbone (and BFP3O 

sidegroup) flipping and twisting, which is typically observed in bisphenol-A polycarbonates or 

polysulfones of similar structure (16). These subambient motions are often attributed to 

toughening mechanisms in engineering thermoplastics. 
10

0.01

0.1

1

10

Tan Delta

1

10

100

1000

10000

Storage Modulus (MPa)

-200 -100 0 100 200 300

Temperature (°C) Universal V3.9A TA Instruments

Figure 6. DMA storage modulus and tan delta signals versus temperature showing Tg and sub-Tg transitions 

for LIN PSF-PO. 

As an initial test of the PSF-PO matrix as a host for conductive salts, membranes were cast from 

solution to contain 1:40 M:O of either Li+ Tf- or Li+ Bim-. A neat sample was also cast for 

comparison. In-plane electrical impedance measurements were carried out as shown in the Bode 

plot in figure 7. The impedance response of the membranes is also plotted against the baseline 

for the empty cell. The measurements were carried out at room temperature (22 °C) and a 

controlled relative humidity of 40% in a humidity chamber. Although there is some deviation 

from the baseline that begins around 10 Hz, all three membranes demonstrate the same trend. 

Although no direct estimate of the bulk resistance could be made based on the Nyquist plot, the 

value is likely to be above 10 GΩ. Also, it is possible that either changes in annealing of the 

membranes or changes in the salt ratio could further affect the resistance. Regardless, the 

PSF-PO matrix is has a very high resistance that may not allow for sufficient resolution of the 

effects of minor levels of branching. 
11

-2 -1 0 1 2 3 4 5 6

4

5

6

7

8

9

10

11

12

13

-200

-150

-100

-50

0

50

100

150

200

log(f)

log(Z)(o)

-phase / deg(+)

Figure 7. Combined Bode plot (|Z|, phase) for LIN-PSF-PO cast (blue: diamond, X) in the presence of 

Li+

 Tf- (red: square, asterisk) or Li+ Bim- (green, up triangle, down triangle) against an empty 

background (black: circle, cross). 

4. Summary 

Linear and long-chain-branched poly(arylene ether sulfone phosphine oxide)s were synthesized 

by an A2 + B2 + B3 method without gelation. The structure and molecular weight were verified 

by NMR and SEC. The thermal transitions were observed through TGA, DSC, and DMA across 

a wide temperature range. Thermal analysis suggests that these polymers retain significant 

modulus while displaying higher than expected levels of hydrophilicity. The detection of 

physical aging due to enhanced bulkiness of the chosen monomers suggests an increase in free 

volume around the chain, which could be explored for complexation of ions during transport. 

However, the initial tests for membrane electrical properties demonstrated very high resistances 

potentially on the order of 10 GΩ, even when cast in the presence of conductive lithium salts. 

Further experiments are necessary to conclude if this result is due to overloading of the salt or 

truly the high bulk resistance of the membrane. Also, through-thickness measurements should 

be carried out to provide an estimate of charge transport in the primary direction of interest. 
12

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3. Mistry, M. K.; Subianto, S.; Choudhury, N. R.; Dutta, N. K. Interfacial Interactions in 

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4. Angell, C. A.; Liu, C.; Sanchez, E. Rubbery Solid Electrolytes With Dominant Cationic 

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6. Forsyth, M.; Jiazeng, S.; MacFarlane, D. R. Novel High Salt Content Polymer Electrolytes 

Based On High Tg Polymers. Electrochimica Acta 2000, 45, 1249–1254. 

7. Imrie, C. T.; Ingram, M. D. Decoupled ion Transport In Mesomorphic Polymer Electrolyte 

Glasses. Electrochimica Acta 2001, 46, 1413–1417. 

8. Wei, X.; Shriver, D. F. Highly Conductive Polymer Electrolytes Containing Rigid 

Polymers. Chemistry of Materials 1998, 10, 2307–2308. 

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List of Symbols, Abbreviations, and Acronyms 

1

H hydrogen 

13C carbon 

19F fluorine 

31P phosphorous 

BFP3O Bis(4-fluorophenyl)phenylphosphine oxide 

DHDPS 4,4’-dihydroxydiphenylsulfone 

DMA dynamic mechanical analysis 

DMAc Dimethylacetamide 

DSC differential scanning calorimetry 

EIS electrical impedance spectroscopy 

FRA Frequency Response Analysis 

FTIR Fourier transform infrared spectroscopy 

IPT ionic polymer transducer 

K2CO3 potassium carbonate 

LCB-PSF-PO long-chain branched polysulfone phosphine oxide 

LCB-X long-chain branched 

Li-Bim lithium bis(trifluoromethane)sulfonimide 

Li-Tf lithium trifluoromethanesulfonate 

LIN linear 

LIN-PSF-PO linear polysulfone phosphine oxide 

MALLS multiangle laser light scattering 

NMP N-methyl pyrrolidone 

NMR nuclear magnetic resonance 

PDI polydispersity indices 
15

PEO poly(ethylene glycol) 

SEC size exclusion chromatography 

TFPPO tris(4-fluorophenyl) phosphine oxide 

TGA thermogravimetric analysis 
NO. OF 

COPIES ORGANIZATION 

16

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