Title: Modular Main-Chain Polybenzoxazines: Thermoplastic Processability with Thermoset Performance

Authors: Levi J. Hamernik & Jeffrey S. Wiggins

DOI: 10.33599/nasampe/s.22.0709

Abstract: Polybenzoxazine thermosets have attracted significant interest as alternatives to conventional matrix polymers owing to their unique properties such as high Tg, low shrinkage, and reduced flammability. However, traditional benzoxazine monomers can be challenging to process and often polymerize into highly crosslinked networks that possess poor toughness. Recently, linear thermoplastics containing benzoxazine moieties within the backbone have been investigated to circumvent these shortcomings. This new class of polybenzoxazines, designated as main-chain benzoxazine polymers (MCBPs), have demonstrated enhanced thermal stability and improved mechanical properties over conventional polybenzoxazine networks. Herein, high-molecular-weight MCBPs are prepared under mild conditions via an imine condensation polymerization. The resulting linear thermoplastics demonstrate tailorable thermomechanical properties that can be processed like traditional thermoplastics but can crosslink through the backbone into thermally stable and mechanically tough polybenzoxazine networks upon further heating. The polymer processability and crosslinking behavior of the various MCBPs are investigated by differential scanning calorimetry and rheological experiments. The thermomechanical properties and thermal stability before and after crosslinking is explored. This work demonstrates the facile preparation of new MCBPs that can be melt processed through traditional thermoplastic techniques and provides insight into the molecular design of next generation polybenzoxazines for composite applications.

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Conference: SAMPE 2022

Publication Date: 2022/05/23

SKU: TP22-0000000709

Pages: 11

Price: $22.00