Viscoelastic and Dielectric Relaxation Behavior of Substituted Poly(p-phenylenes)

Connolly, Michael; Karasz, Frank E.; Trimmer, Mark

doi:10.1021/ma00110a022

Cited by 29 publications

(18 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The glass transition temperatures T g measured for the PPBP (153°C) and the PBP (160°C) are in good agreement with those given in the literature [26,27]. The lower T g of PPBP is due to the phenoxy group, which probably modifies the organization of the macromolecule and leads to a better flexibility of the side chain.…”

Section: Thermal Propertiessupporting

confidence: 87%

Sulfonated derivatives of polyparaphenylene as proton conducting membranes for direct methanol fuel cell application

Ninivin

Balland-Longeau

Demattei

et al. 2004

Journal of Applied Electrochemistry

View full text Add to dashboard Cite

Proton conducting polymers derived from polybenzoyl-1,4-phenylene (PBP) and poly-p-phenoxybenzoyl-1,4-phenylene (PPBP) were synthesized by the 'Colon synthesis technique'. The sulfonation of these proton conducting polymers was carried out using either sulphuric acid or tetramethylsiliylchlorosulfonate (TMSCl) as sulfonating agent, and their thermal properties were evaluated. Both sulfonated PBP and PPBP are thermally stable up to at least 215°C. The sulfonated sPPBP exhibited good conductivity as proton conducting membranes at room temperature and were tested as electrolyte membranes for a single direct methanol fuel cell (DMFC) in terms of water absorption, methanol permeability and electrical performance. The water uptake of the sPPBP was found to be larger than that of the sPBP, i.e., 65 and 43 mol%, respectively. The permeability to methanol was found to be 10 times lower than sPPBP and sPBP compared to a Nafion Ò membrane. In spite of this, performance in a single DMFC was found to be twice inferior to that with Nafion Ò 117. Optimisation of the sulfonation level and of the electrode-membrane interfaces was lead to better results.

show abstract

Section: Thermal Propertiessupporting

confidence: 87%

Sulfonated derivatives of polyparaphenylene as proton conducting membranes for direct methanol fuel cell application

Ninivin

Balland-Longeau

Demattei

et al. 2004

Journal of Applied Electrochemistry

View full text Add to dashboard Cite

show abstract

“…As ␤ decreases the breadth of the distribution of relaxation times increases. 31 The ␤ parameter can be determined using a numerical method to solve the transform of the KWW equation, which was developed by Weiss et al 32,33 :…”

Section: Elastomer-modified Epoxy-methacrylate Seqipnsmentioning

confidence: 99%

Synthesis and properties of elastomer‐modified epoxy–methacrylate sequential interpenetrating networks

Sands

Jensen

Fink

et al. 2001

J of Applied Polymer Sci

View full text Add to dashboard Cite

ABSTRACT:The structure and properties of copolymerized sequential-interpenetrating networks (SeqIPNs) synthesized from amine-cured epoxies and free-radical polymerized dimethacrylates were examined. Materials were synthesized with and without the incorporation of an epoxy-terminated butadiene-nitrile reactive elastomer. Synthesis proceeded through full thermal cure of the epoxy-amine network, followed by polymerization of the methacrylate network. The methacrylate reactions were free-radically induced using thermal (peroxide-initiated) or photochemical [electron-beam (e-beam)] techniques. Fourier transform infrared spectroscopy was used to monitor epoxy-amine step-growth polymerization in situ and to measure final cure conversion of methacrylates. Structural examination of the IPNs using atomic force microscopy and scanning electron microscopy revealed microphase separation in the neat-SeqIPN materials and macroscopic phase separation of rubber-rich domains for elastomer-modified networks. Dynamic mechanical analysis of the SeqIPN determined that the properties of the network are strongly dependent on the cure conditions. Furthermore, the viscoelastic behavior of the e-beam-cured SeqIPN could be adequately described by the WilliamsLandel-Ferry and Kohrausch-Willams-Watts equations, presumably because of a strong coupling between the epoxy-amine and methacrylate networks.

show abstract

“…in a study of the a-relaxation behavior of substituted poly(phenylenes). 13 Such reported differfitted to the Arrhenius equation to determine the apparent activation energy, E, of the a-relaxences in the temperature locations of the relaxation peaks are not limited to neat polymers. DRS ation.…”

Section: Dielectric Studiesmentioning

confidence: 99%

Dielectric and dynamic mechanical relaxation studies on poly(aryl ether ketone)s

Goodwin¹,

Hay²

1998

J. Polym. Sci. B Polym. Phys.

View full text Add to dashboard Cite

The relaxation behavior of four amorphous poly(aryl ether ketone)s was investigated using dielectric relaxation spectroscopy and dynamic mechanical analysis. The temperature dependence of the relaxation times of the glass transition process and the cooperative nature of this process were unaffected by changes in polymer structure. The temperature location of the loss peaks for all polymers progressed smoothly between the low frequency of the mechanical measurements and the higher frequencies of the dielectric probe. Differences were observed in mechanical activation energy and dielectric relaxation strength for one polymer which contained a significant concentration of meta linkages, compared with the para‐linked polymers, while relaxation broadness was generally greater in the dynamic mechanical mode. Changes in chemical structure had little effect on the shape, intensity, and location of the β‐relaxation peak, the main observation being that the Arrhenius activation energy measured by dynamic mechanical analysis was significantly higher than that calculated from the dielectric data. The dielectric β‐relaxation was sensitive to absorbed moisture. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 851–859, 1998

show abstract

Viscoelastic and Dielectric Relaxation Behavior of Substituted Poly(p-phenylenes)

Cited by 29 publications

References 2 publications

Sulfonated derivatives of polyparaphenylene as proton conducting membranes for direct methanol fuel cell application

Sulfonated derivatives of polyparaphenylene as proton conducting membranes for direct methanol fuel cell application

Synthesis and properties of elastomer‐modified epoxy–methacrylate sequential interpenetrating networks

Dielectric and dynamic mechanical relaxation studies on poly(aryl ether ketone)s

Contact Info

Product

Resources

About