Plasma -Activated Self Healing Composites Using Microcapsules and Dynamic Covalent Bods

In advanced structural systems including those used in aerospace, automotive, and civil infrastructure the durability and reliability of load-bearing components are of paramount importance. This paper presents an innovative self-healing composite material that autonomously repairs damage by integrating microcapsules with dynamic covalent chemistry. Poly(ureaformaldehyde) (PUF) microcapsules, with diameters ranging from ۱۰ to ۵۰ µm and loaded with a reactive healing agent, are uniformly dispersed within an epoxy matrix that is chemically functionalized with reversible Diels Alder (DA) bonds formed between furan and maleimide groups. To enhance the capsule-matrix interfacial adhesion, the microcapsules undergo atmospheric dielectric barrier discharge (DBD) plasma treatment to graft OH and COOH groups onto their surfaces. Concurrently, the epoxy matrix is activated via low-pressure radio-frequency (RF) plasma treatment, which reduces the activation energy for the DA reaction from ۸۰ to ۶۰ kJ·mol⁻¹. As a result, experimental measurements indicate an approximately ۶۳۴-fold increase in healing rate under service-relevant conditions. Mechanical tests reveal that the plasma-enhanced composite achieves a ۲۳% increase in tensile strength, a ۱۴۰% improvement in fracture toughness, and a doubling of fatigue life compared to untreated counterparts. This dual-mechanism approach, combining microcapsule-mediated healing with dynamic covalent bond reformation, represents a novel paradigm with the potential to extend service life and reduce maintenance costs of high-performance structural components.

کلیدواژه ها:

Self healing ، Composite Materials ، Plasma Activation ، Microcapsules ، Dynamic Covalent Bonds