Sustainable High-Solids Bio-Based Core–Shell Latexes with Itaconic Acid for Tunable Mechanics and Ion Binding

The development of sustainable emulsion polymerization strategies that simultaneously achieve high solid contents and efficient incorporation of biobased monomers remains a central challenge in green polymer chemistry and scalable materials manufacturing. Herein, we report a facile one-pot emulsion polymerization approach for synthesizing high-solid-content core/shell latex nanoparticles composed of a complementary soft poly(methyl methacrylate-co-butyl acrylate) core and a hard, biobased poly(itaconic acid) (PIA) shell. Through formulation optimization, latexes with up to 50 wt % monomer loading, >90% conversion, and excellent colloidal stability were achieved. A high biomass itaconic acid (IA) content (up to 40 wt %) was critical, as IA acted synergistically as both a renewable monomer and an amphiphilic stabilizer (cosurfactant), promoting efficient micelle nucleation and interfacial localization under high-solids conditions and eliminating the need for conventional multistage core/shell synthesis. Transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), and tensile testing confirmed the formation of well-defined core/shell nanoparticles exhibiting distinct dual glass-transition temperatures and yielding cast films with mechanical properties readily tunable from ductile to stiff. Moreover, the IA-rich shell supplied abundant accessible carboxyl groups, enabling efficient Cu2+ coordination with uptake capacities of up to 167 mg g–1, ranking these materials among the most effective polymer-based Cu2+ sorbents reported. Overall, this work establishes a scalable and environmentally benign strategy for producing biobased core/shell latexes that integrate structural tunability with ion-chelating functionality, highlighting their potential for sustainable ion-exchange and separation applications.