Solution polymerization of polybenzimidazole

Polybenzimidazoles (PBI) are an important class of heterocyclic polymers that exhibit high thermal and oxidative stabilities. The two dominant polymerization methods used for the synthesis of PBI are the melt/solid polymerization route and solution polymerization using polyphosphoric acid as the solvent. Both methods have been widely used to produce high-molecular weight PBI, but also highlight the obvious absence of a practical organic solution-based method of polymerization. This current work explores the synthesis of high-molecular weight meta-PBI in N,N-dimethyl acetamide (DMAc). Initially, model compound studies examined the reactivity of small molecules with various chemical functionalities that could be used to produce 2-phenyl-benzimidazole in high yield with minimal side reactions. 1H NMR and FTIR studies indicated that benzimidazoles could be efficiently synthesized in DMAc by reaction of an o-diamine and the bisulfite adduct of an aromatic aldehyde. Polymerizations were conducted at various polymer concentrations (2-26 wt % polymer) using difunctional monomers to optimize reaction conditions in DMAc which resulted in the preparation of high-molecular weight m-PBI (inherent viscosities up to 1.3 dL g−1). TGA and DSC confirmed that m-PBI produced via this route has comparable properties to that of commercial m-PBI. This method is advantageous in that it not only allows for high-polymer concentrations of m-PBI to be synthesized directly and efficiently, but can be applied to the synthesis of many PBI derivatives. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1795–1802

[1]  B. Benicewicz,et al.  Investigation of sequence isomer effects in AB-polybenzimidazole polymers , 2014 .

[2]  Karren L. More,et al.  A Comparative Study of Phosphoric Acid-Doped m-PBI Membranes , 2014 .

[3]  X. Li,et al.  Synthesis and properties of phenylindane-containing polybenzimidazole (PBI) for high-temperature polymer electrolyte membrane fuel cells (PEMFCs) , 2013 .

[4]  X. Li,et al.  Synthesis and Characterization of a New Fluorine‐Containing Polybenzimidazole (PBI) for Proton‐Conducting Membranes in Fuel Cells , 2013 .

[5]  D. Stolten,et al.  Carbon NMR investigation of the polybenzimidazole–dimethylacetamide interactions in membranes for fuel cells , 2013 .

[6]  Kevin Huang,et al.  Performance of vapor-fed direct dimethyl ether fuel cell utilizing high temperature polybenzimidazole polymer electrolyte membrane , 2012 .

[7]  B. Benicewicz,et al.  Polyphenylquinoxaline-based proton exchange membranes synthesized via the PPA Process for high temperature fuel cell systems , 2012 .

[8]  B. Benicewicz,et al.  A new sequence isomer of AB‐polybenzimidazole for high‐temperature PEM fuel cells , 2012 .

[9]  G. Qian,et al.  Fuel Impurity Effects on High Temperature PBI Based Fuel Cell Membranes , 2011 .

[10]  B. Benicewicz,et al.  Synthesis and Properties of Random Copolymers of Functionalised Polybenzimidazoles for High Temperature Fuel Cells , 2011 .

[11]  T. Jana,et al.  Structurally isomeric monomers Directed copolymerization of polybenzimidazoles and their properties , 2010 .

[12]  Brian C. Benicewicz,et al.  Sulfonated Polybenzimidazoles for High Temperature PEM Fuel Cells , 2010 .

[13]  Brian C. Benicewicz,et al.  Synthesis and Properties of Functionalized Polybenzimidazoles for High-Temperature PEMFCs , 2009 .

[14]  Robert F. Savinell,et al.  High temperature proton exchange membranes based on polybenzimidazoles for fuel cells , 2009 .

[15]  Brian C. Benicewicz,et al.  Polybenzimidazole/Acid Complexes as High-Temperature Membranes , 2008 .

[16]  T. Jana,et al.  Aggregation Behavior of Polybenzimidazole in Aprotic Polar Solvent , 2007 .

[17]  Haifeng Zhang,et al.  Determination of the Molecular Parameters and Studies of the Chain Conformation of Polybenzimidazole in DMAc/LiCl , 2006 .

[18]  Qingfeng Li,et al.  Water uptake and acid doping of polybenzimidazoles as electrolyte membranes for fuel cells , 2004 .

[19]  M. Vaultier,et al.  Synthesis, Characterization, and Studies of Heat-Resistant Poly(ether benzimidazole)s , 1997 .

[20]  E. Powers,et al.  History and Development of Polybenzimidazoles , 1986 .

[21]  R. Young,et al.  Introduction to Polymers , 1983 .

[22]  R. Montgomery,et al.  Properties and Applications of Celanese PBI—Polybenzimidazole Fiber , 1982 .

[23]  E. Neuse Aromatic polybenzimidazoles. Syntheses, properties, and applications , 1982 .

[24]  T. Kojima Studies of molecular aggregation of a polybenzimidazole in solution by fluorescence spectroscopy , 1980 .

[25]  A. F. Pozharskii,et al.  Heterocyclic analogs of pleiadiene , 1980 .

[26]  M. Bingham,et al.  A study of the thermal behaviour of flame-resistant fibres and fabrics , 1975 .

[27]  C. Marvel,et al.  Benzimidazole polymers from aldehydes and tetraamines , 1970 .

[28]  G. Holan,et al.  2-trihalogenomethylbenzazoles. II. Reactions of 2-trihalogenomethylbenzimidazoles with ammonia and amines. , 1967, Journal of the Chemical Society. Perkin transactions 1.