Synthesis of Multilayer Core‐Shell Acrylic Impact Modifiers and Their Impact on the Performance Optimization of Poly (Methyl Methacrylate)

ABSTRACT This study investigates the toughening effects of three types of acrylic impact modifier (AIM) structures—bilayer, trilayer, and functionalized—on polymethyl methacrylate (PMMA). The melt blending technology was employed to examine how AIM structural variations influence the mechanical and optical properties of PMMA. First, bilayer AIMs with varying particle sizes were synthesized. The results showed that an optimal impact resistance was achieved when the particle size of P(BA‐co‐St) was 269 nm, with the optical properties remaining above 88%. Next, trilayer AIMs were prepared to assess the influence of different core materials on toughening performance. These trilayer AIMs enhanced the crack propagation resistance of PMMA but led to a slight decrease in optical properties. Finally, functionalized AIMs were developed by introducing acrylic acid (AA) functional groups into the shell layer, improving the interfacial adhesion between AIM and PMMA, which significantly enhanced the mechanical performance. The findings demonstrate that optimization of particle size, layer structure, and functionalization effectively improves the impact resistance and overall performance of PMMA. With excellent optical properties maintained, the impact strength is increased by four times, providing new solutions for its application in the construction, automotive, and electronics industries.