Structure and properties of a flame retardant ternary vitrimer regulated by cyclic and long-chain dicarboxylic acids. (January 2023)

• Record Type: Journal Article
• Authors: Zhang, Di; Cao, Weihong; Guo, Zhenghong; Yan, Hongqiang; Fang, Zhengping; Chen, Peng; Li, Juan
• Is Part Of: Polymer degradation and stability. Volume 207(2023)
• Publication Date: 2023-01
• Subjects: Vitrimer -- Flame retardant -- Long-chain -- Transesterification -- Recyclable; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2022.110234
• Languages: English
• ISSNs: 0141-3910

Abstract

Highlights: An epoxy monomer containing a phosphonate group (E) was used to modify the flame retardancy of a vitrimer. Cyclic and long-chain dicarboxylic acids were blended to regulate the flame retardant and mechanical properties of epoxy. E/1C/2D blend displays a UL-94 V0 rating, good tensile strength and quick recovery ability. The tensile strength does not decrease significantly over two molding cycles. Abstract: A vitrimer is a kind of polymer with a dynamic network that has received extensive attention. An epoxy monomer containing a phosphonate group (E) has been used to endow a vitrimer with flame retardancy. 1, 4-cyclohexanedicarboxylic acid (CA) was used as a diacid monomer. Dodecanedioic acid (DA) containing a long aliphatic chain was used as a third monomer to regulate the structure and properties of the vitrimer. The flame retardant properties were investigated using UL-94 vertical combustion, limiting oxygen index (LOI). The results showed that the E/1C/2D vitrimer containing CA/DA (mole ratio1:2) displays a UL-94 V-0 rating and a LOI value of 31%. Furthermore, the vitrimers possesse excellent recyclable and multiple shape memory performance. The E/1C/2D vitrimer may be structurally modified rapidly via transesterification reaction between an ester and neighboring β‑hydroxy groups at 170 °C. The recycling efficiency is nearly 100%. The tensile strength and modulus of E/1C/2D may be as high as 97 MPa and 2173 MPa, respectively. The tensile strength is not significantly decreased as a consequence of two reformation events. A simple method for the regulation of the flame retardancy and mechanical properties of vitrimers has been demonstrated.