Title: Cure Path Dependency on Meta-Alkyl Substituted Aniline Based Polybenzoxazine Thermosets

Authors: Bernardo Barea-López, Benjamin L.G. Morasch, Otoniel Durán, and Dr. Jeffrey S. Wiggins

DOI: 10.33599/nasampe/s.22.0758

Abstract: Polybenzoxazine chemistry is an attractive alternative to more traditional matrices used in the aerospace industry due to the high glass transition temperature, UV resistance, low coefficient of thermal expansion and low water absorption. Ishida et al. proposed that meta-alkyl substituted aniline based polybenzoxazines exhibit two different crosslinking mechanisms shown in Scheme 1.[1] In route A, the opening of the oxazine ring leads to the formation of a phenolic Mannich bridge. In route B, meta-alkyl substituted aniline based polybenzoxazine can undergo the formation of an arylamine Mannich bridge. It has been reported that both mechanisms have dissimilar activation energies.[2] However, it is still unknown how different cure protocols would affect the network architecture of meta-alkyl substituted aniline based polybenzoxazines thermosets. Herein, chemorheological and thermomechanical characterizations were performed to study the benzoxazine network formation of the same monomer (BA-35mt) that was cured from 150 °C to 250 °C at four different ramp rates: 0.1 °C/min, 0.5 °C/min, 1.0 °C/min, and 2.0 °C/min. Dynamic Mechanical Analysis (DMA) , Thermogravimetric Analysis (TGA) and moisture uptake tests were employed to analyze the properties of the four fully cured BA-35mt networks. Furthermore, gelation tests were performed to understand the kinetics of the crosslink reaction. This research seeks to establish the effect of different cure protocols on the network formation of meta-substituted aniline based polybenzoxazine thermosets.

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Conference: SAMPE 2022

Publication Date: 2022/05/23

SKU: TP22-0000000758

Pages: 10

Price: $20.00