Exchangeable disulfide bond containing highly flexible epoxy vitrimers with shape‐memory, self‐healing, and UV shielding attributes

• Published in: Polymers for advanced technologies Vol. 35; no. 1
• Main Authors: Dutta, Kalyan, Karak, Niranjan
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.2024; Wiley Subscription Services, Inc
• Subjects: Chemical bonds; Curing; Curing agents; dynamic disulfide linkage; Elongation; Epichlorohydrin; epoxy; Epoxy resins; Healing; Oxidation resistance; Radiation shielding; Recyclable materials; self‐healing; Shape memory; Tensile strength; Thin films; Ultraviolet radiation; Vitrimers; VOCs; Volatile organic compounds
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.6286

With the rise in momentous resource wastage and severe environmental pollution, a viable path for sustainability is through the use of reprocessable and recyclable materials like vitrimers. Herein, we demonstrated the synthesis of dynamic disulfide‐containing epoxy resin by condensing an amide derivative of 2,2′‐dithiodibenzoic acid with epichlorohydrin. The aforementioned epoxy resin was cured utilizing the two bio‐based curing agents poly(amido amine) and cystamine to produce three distinct epoxy vitrimers. The use of reactive diluent reduced the generation of volatile organic compounds during the curing process. The existence of disulfide bond and aliphatic moiety in the epoxy vitrimers established high elongation at break with good tensile strength. Owing to the dynamic bond, the vitrimers exhibited self‐healing properties with a healing efficiency of 71.48% along with good shape memory abilities. Additionally, the disulfide bond dynamic exchange reaction allowed the polymer chain architecture to topologically reorganize, making them reprocessable and degradable. Moreover, these epoxy vitrimers have the ability to shield ultraviolet radiation as well as inhibits oxidation, and have good chemical resistance properties. The investigated epoxy thermoset thus provides a lot of potential for application as a durable thin film material.