Achieving outstanding toughness of PMMA while retaining its strength, stiffness, and transparency using in situ developed TPEE nanofibrils. (3rd May 2023)

• Record Type: Journal Article
• Authors: Rahman, Saadman Sakib; Mahmud, Mayesha Binte; Monfared, Ali Reza; Lee, Patrick C.; Park, Chul B.
• Is Part Of: Composites science and technology. Volume 236(2023)
• Publication Date: 2023-05-03
• Subjects: A. polymer-matrix composites (PMCs) -- A. Nano composites -- B. Mechanical properties -- D. Fractography -- In situ fibrillation; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2023.109994
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Poly(methyl methacrylate) (PMMA) is an amorphous thermoplastic with high strength, high stiffness, and excellent light transmittance. However, PMMA is very brittle at room temperature, which limits its ubiquitous applications. In this article, we report a scalable, cost-effective, and environmentally-friendly method for enhancing the toughness of PMMA without sacrificing its strength, stiffness, and transparency. PMMA composites comprising in situ developed nanofibrils of thermoplastic polyester elastomer (TPEE) were fabricated following the established concept of converting instead of adding . Remarkably, even only 1 wt% of TPEE nanofibrils with an average diameter of ∼50 nm provided a ∼255% increment in the toughness and ∼29.2% improvement in the impact strength of PMMA, while still maintaining its strength, stiffness, and transparency. In comparison, when TPEE was dispersed and distributed as spheroids, no toughening effect was observed at 1 wt% of TPEE content, and even 10 wt% of TPEE content provided only a ∼150% increment in the toughness, which was, however, accompanied by a decrease in strength, stiffness, and transparency. Herein, we present the effect of both TPEE structure (spheroids vs nanofibrils) and concentration on the rheological, thermomechanical, light transmittance, and mechanical properties of the PMMA/nanofibril-TPEE composites. Based on the fractography and small-angle X-ray scattering analysis, we propose that nanofibril-induced multiple crazing is one of the major sources of the greatly improved toughness. The composites presented in this article can be used in applications that require unique combinations of high toughness, high strength, high stiffness, and excellent transparency. Graphical abstract: Image 1