Nanofibre preparation of non-processable polymers by solid-state polymerization of molecularly self-assembled monomers

Abstract

Polybisbenzimidazobenzophenanthroline-dione (BBB) is a high-performance polymer which is characterized by very high mechanical strength in combination with exceptional thermal stability, but it cannot be processed to electrospun fibres for any useful applications due to its insolubility and infusibility. We overcame all obstacles in the electrospinning of BBB by a new bottom-up, and facile approach for the solid-state polymerization of self-assembled monomer precursors. Key to this new strategy is the incorporation of a high molecular weight sacrificial polymer to aid in fibre formation. The resulting electrospun BBB fibres and belts prepared thereof according to this new approach are very strong and show excellent thermal stability. We envisage that this procedure could be applied to other classes of non-processable high-performance polymers for the preparation of electrospun fibres for applications such as filtration, sound insulation, battery separation, electrodes, fire protection, and reaction engineering under demanding conditions.

Low Density, Thermally Stable, and Intrinsic Flame Retardant Poly(bis(benzimidazo)Benzophenanthroline‐dione) Sponge

“…The chemical structures of the BBB nanofibers and PVA–BBB sponge, as well as A‐BBB sponge after heat treatment, were determined by FTIR spectra ( Figure a). Comparing the characteristic absorptions at 1698, 1547, and 992 cm −1 with previous report, the formation of BBB polymer and the retained molecular structure even after heat treatment were proved . The characteristic absorptions of PVA at 3313 and 2917 cm −1 belonging to OH and CH disappeared after heat treatment at 500 °C, signifying successful removal of PVA by pyrolysis.…”

“…Since it is insoluble and infusible polymer, the processing of this polymer requires special procedures. Recently, a new approach of making BBB fibers by electrospinning of the corresponding monomers and subsequent polymerization in the solid‐state was reported . The BBB fibers made by this procedure have a smooth surface and uniform diameter in range of 700–800 nm as shown in Figure a,b.…”

“…The BBB nanofibers can be produced by electrospinning as described in the previous literature . Equimolar amounts of the two monomers, 3,3′‐diaminobenzidene (DAB) (2.1427 g, 0.01 mol) and 1,4,5,8‐naphthalene tetracarboxylic acid (NTCA) (3.0421 g, 0.01 mol)), and 2.22 g PVP was added in 30 g DMF and stirred for 8 h at room temperature to form a homogeneous solution.…”

“…However, the investigation and application of BBB has not moved forward for a long period, due to its insolubility and infusibility. Recently, a new approach for making BBB fibers was reported by electrospinning the corresponding monomers with a template polymer followed by solid‐state polymerization at high temperature with simultaneous pyrolysis of the template polymer …”

Synthesis and Characterization of Fully Conjugated Ladder Naphthalene Bisimide Copolymers

“…Recently, fully conjugated ladder polymers have been leaded to rapid development in the field of organic optoelectronic materials due to their unique fused structure and excellent properties [1,2,3,4,5,6,7,8,9]. The main chain on the fully conjugated ladder polymer is π-conjugated and fused structure [10,11,12,13,14].…”