Boosting m-aramids performance with p-oriented aromatic amide side chains

• High-performance m -aramid copolymers containing p -aramid side chains were obtained. • The aramid lateral chains were terminated with nitro groups. • Copolymers resulted in a 48% increase in the Young’s modulus compared to MPIA. • The performance of the new copolymers improved in upon exposure to hydrogen. • They can be applied as steel coatings in high-pressure hydrogen storage. This study aimed to enhance the mechanical properties of m -aramids by incorporating varying percentages of p -aramid side chains through copolymerization while ensuring solubility for practical applications. The mechanical performance of the resulting copolymers was compared with the commercial m -aramid, MPIA (poly( m -phenylene terephthalamide)). Notably, even with a 20% incorporation of p -aramid side chains, there was a substantial increase of 48% in Young’s modulus and 7% in tensile strength compared to MPIA. Additionally, the nitro group capping the p -aramid side chains demonstrated significant efficacy in enhancing the mechanical performance of the materials upon exposure to hydrogen. Specifically, there was an increase of more than 11% in Young’s modulus upon initial contact with hydrogen. This finding suggests potential applications in protective coatings for stainless steel used in high-pressure hydrogen storage environments. In such applications, exposure to hydrogen can accelerate embrittlement and limit operational lifespan, and coating with these materials can mitigate embrittlement and improve operational lifespan.