Curing Behavior and Mechanical Properties of Tetra-Functional Epoxy Reinforced with Polyethyleneimine-Functionalized MXene

Wazalwar, R and Tripathi, M and Raichur, AM (2022) Curing Behavior and Mechanical Properties of Tetra-Functional Epoxy Reinforced with Polyethyleneimine-Functionalized MXene. In: ACS Applied Polymer Materials, 4 (4). pp. 2573-2584.

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Abstract

The aerospace industry has started shifting toward polymer composites, especially epoxy-based composites. Because epoxy is inherently brittle, it must be suitably reinforced to enhance its fracture properties and make it suitable for aerospace applications. In this regard, we studied surface-modified Ti3C2 nanosheets as toughening agents for aerospace-grade epoxy composites. Ti3C2Tx (T = O, OH, and F) nanosheets were synthesized by acid etching of the Ti3AlC2 precursor and further functionalized with polyethyleneimine (PEI) to improve their degree of exfoliation and enhance their degree of interaction with the epoxy matrix. Epoxy composites containing 0.1, 0.5, and 1.0 wt PEI-Ti3C2Tx nanosheets were synthesized. These composites were studied for their curing behavior and mechanical properties. The isoconversional Starink method was used to calculate the curing activation energy. Compared to neat epoxy, the PEI-Ti3C2Tx nanosheets showed a catalytic effect on curing by lowering the curing activation energy. A 40 higher compressive strength was observed in 0.5 wt PEI-Ti3C2Tx/epoxy composites, compared to neat epoxy. The KIC and GIC of the 0.5 wt PEI-Ti3C2Tx/epoxy composite were 70 and 140 higher than those of neat epoxy, respectively. The fracture properties improved due to crack deflection, crack blunting, and enhanced filler-matrix interaction. At 1.0 wt PEI-Ti3C2Tx loading, the nanosheets began agglomerating, which caused a reduction in the mechanical properties. The storage modulus and Tg of the PEI-Ti3C2Tx/epoxy composites were also significantly higher than those of neat epoxy. It was observed that blank Ti3C2Tx did not cause a remarkable improvement in the properties of epoxy composites. Hence, PEI functionalization was instrumental in achieving uniform filler dispersion and favorable filler-matrix interaction. © 2022 American Chemical Society.

Item Type:	Journal Article
Publication:	ACS Applied Polymer Materials
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the American Chemical Society.
Keywords:	Activation energy; Aerospace applications; Aerospace industry; Aluminum compounds; Composite materials; Compressive strength; Cracks; Etching; Fillers; Fracture; Fracture toughness; Kinetics; Nanosheets; Reinforcement; Titanium compounds, Curing behavior; Epoxy; Epoxy composite; Epoxy curing; Fracture property; Functionalized; Mxenes; Poly(ethyleneimine); Polymer composite; Toughening mechanisms, Curing
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	17 May 2022 09:10
Last Modified:	24 Jun 2022 05:17
URI:	https://eprints.iisc.ac.in/id/eprint/71703

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