Nanoparticles of polydopamine for improving mechanical and flame-retardant properties of an epoxy resin

• Published in: Composites. Part B, Engineering Vol. 186; p. 107828
• Main Authors: Yang, Wenmu, Wu, Shuying, Yang, Wei, Chun-Yin Yuen, Anthony, Zhou, Yang, Yeoh, Guan, Boyer, Cyrille, Wang, Chun H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2020
• Subjects: Flammability; Mechanical properties; Nanocomposites; Polydopamine; Polydopamine; Flammability; Mechanical properties; Nanocomposites
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2020.107828

A bio-flame retardant filler was synthesized via the self-polymerization of dopamine hydrochloride in alkaline condition, yielding nano-sized polydopamine (nano-PDA) particles ranging between 50 and 100 nm in diameters. Adding a small amount (2 wt%) of the nano-PDA particles into an epoxy can remarkably reduce the value of peak heat release rate by 53.6%, exceeding the performance aluminum trihydroxide (ATH) particles at 10 wt%. The significant improvement in flame retardancy at a relatively low loading of PDA has been found to originate from several key mechanisms including radical scavenging, higher char yield, and production of CO2. Furthermore, the addition of nano-PDA in the epoxy resin increased the tensile strength by ~6%. In contrast, the addition of common flame retardant, such as ATH, to achieve the same increase in flame retardancy of epoxy would reduce the tensile strength by 22%. This improvement in mechanical properties is attributed to the better bonding between PDA particles with epoxy than ATH with epoxy.