Functional Aromatic Poly(1,3,4-Oxadiazole-Ether)s with Benzimidazole Pendants: Synthesis, Thermal and Dielectric Studies.

Shimoga D Ganesh,Madhu B Jayanna,Vasantakumar K Pai,Mahadevappa Y Kariduraganavar

doi:10.1155/2014/790702

Shimoga D Ganesh, Madhu B Jayanna + Show 2 more

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https://doi.org/10.1155/2014/790702

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Abstract

Poly(1,3,4-oxadiazole-ether) with reactive carboxylic acid pendants was synthesized from solution polymerization via nucleophilic displacement polycondensation among 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (BFPOx) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). Without altering the polymeric segments, benzimidazole modified poly(1,3,4-oxadiazole-ether)s were prepared by varying stoichiometric ratios of 1,2-phenylenediamine. The molecular structural characterization of these polymers was achieved by, FT-IR, NMR, TGA, elemental analysis, and analytical techniques. The weight-average molecular weight of virgin polymer with carboxylic acid functionality was determined by gel permeation chromatography (GPC) and was found to be 22400 (Mw/Mn = 2.07). All the synthesized polyethers were compressed into pellets and electrical contacts were established to perform dielectric properties.

Highlights

High performance polymers are of outstanding significance as light emitting diodes, nonlinear optical devices, and photovoltaic cells [1, 2]
The present paper describes the synthesis of a poly(1,3,4oxadiazole-ether) that comprises carboxylic acid moiety (Figure 1) and its respective benzimidazole derivatives, afforded by polyphosphoric acid condensation with o-phenylene diamine at different mass percentages with respect to the virgin polymer
The synthesis of new polymer VALPOx with active carboxylic acid moiety was achieved via conventional aromatic nucleophilic substitution polymerization technique from 4,4󸀠-bis(4-hydroxyphenyl) valeric acid and 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole; the polycondensation was carried out at elevated temperature in N-methyl pyrrolidinone (NMP)/toluene azeotrope in presence of anhydrous pulverised potassium carbonate as catalyst

Summary

Introduction

High performance polymers are of outstanding significance as light emitting diodes, nonlinear optical devices, and photovoltaic cells [1, 2]. Polymers bearing the carboxylic acid functionality can be converted practically to benzimidazoles; polymers with various heterocyclic units are widely used and studied for International Scholarly Research Notices Their good dielectric and pyroelectric performances [14, 15]. Benzimidazole and 1,3,4,-oxadiazole units in main and side chain of the polymer can withstand extreme conditions without an extensive loss of properties and can be widely used in the aerospace industry, where thermal stability is a prime obligation [16] Both heterocycles are best recognized for their admirable thermal resistance with good electrical properties [17, 18], due to their customary applications; various functional groups [19,20,21,22] have paid much attention to the physicochemical properties of polymeric stuff, mainly because of the unique properties of each individual. The monomer and synthesized polymers were well characterized with various spectroscopic techniques, and the dielectric performance of the polymers was investigated

Experimental

Synthesis

Results and Discussion

Conclusion

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