A new method to improve the stability, tensile strength, and heat resistant properties of shape-memory epoxy resins: Two-stages curing

• Published in: Journal of applied polymer science 2014-02, Vol.131 (4), p.n/a
• Main Authors: Sun, He, Liu, Yuyan, Tan, Huifeng, Du, Xingwen
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical properties; epoxy resins; Exact sciences and technology; Materials science; Polymer industry, paints, wood; Polymers; Properties and testing; shape-memory; Technology of polymers; two-stage curing
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.39882

ABSTRACT In this article, we design a new thermal curing method: two‐stage curing. The purpose of using this approach is to maintain the excellent shape‐memory property of epoxy resin system after first stage curing, and the material can be folded in small size to storage or transportation and recovery its original shape commodiously by heating temperature. Then, after second stage curing, the stability, glass transition temperature(Tg), and tensile strength of material can be improved effectively. For this aim, a series of mixtures have been prepared. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), tensile test, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and fold‐deploy shape‐memory test have been used to characterize the feasibility of two‐stage curing process, curing degree, tensile strength, morphology, thermodynamic properties, and shape‐memory performance of these polymers. DSC results show that two independent curing stages can be achieved successfully. Tensile tests and DMA results suggest that tensile strength and heat resistance have been improved after the second curing stage. SEM results reveal that the addition of latent curing agent do not change the fracture mechanism. Furthermore, the fold‐deploy shape‐memory tests prove that the composites after first stage curing possess eximious shape‐memory property. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39882.