High environmental tolerance is a critical requirement for coating applications

particularly in automotive paint. This study successfully fabricated ordered porous photonic microspheres with poly(methyl methacrylate) (PMMA) as the framework using an organized spontaneous emulsification (OSE) mechanism

showing vibrant and adjustable structural colors. PMMA with narrow molecular weight distributions was synthesized via atom transfer radical polymerization (ATRP)

and the efficient removal of terminal double bonds resulting from disproportionation termination was achieved through thiol-ene click reactions. Additionally

PMMA macromonomers with norbornene units were prepared through esterification reactions. By employing sequential ring-opening metathesis polymerization (ROMP)

(poly(norbornene-g-PMMA)-b-(poly(norbornene-g-PEO)) (PMMA-b-PEO) bottlebrush block copolymers (BBCPs) were successfully synthesized with tunable number-average molecular weights ranging from 174 to 359 kDa and low PDIs below 1.2. In the OSE process

bio-based and environmentally safe anisole was utilized as the oil phase instead of toluene

enhancing the safety and eco-friendliness of the material preparation process

eliminating potential harmful residues

and facilitating large-scale production and application. PMMA-based structural color pigments are anticipated to demonstrate outstanding weather resistance and offer significant potential for applications like automotive paint coatings.