Structural modification of photochromic microcapsule shell to enhance acid resistance

Enhancement of weather fastness and acid resistance of photochromic (PC) materials when exposed to outdoor actual weather conditions is crucial for practical application. In this paper, by introducing amine and ether bonding groups, we have developed a typical composite structure shell with strong acid resistance, high sealing capacity and good fatigue resistance, then further self-assembled and embedded photo-transformation powder. The acid resistance, photochromic response, fatigue resistance and thermal stability of fabricated photochromic microcapsule were investigated systematically. Not only the obtained end products exhibited excellent photochromic ability, also the retention of absorption reached 95.97 % under 100 times cycles of visible light irradiation (λ>420 nm) and ultraviolet light irradiation (λ<400nm), uninterruptedly. Here, we prepare stabilized photochromic microcapsules utilizing polyetheramine (PEA) modified melamine formaldehyde (MF) as shell material for further application in the field of UV indication in extreme environments such as viscose fiber spinning.