Photopolymerization and Optical Properties of Magnesium Phthalocyanine‐Acrylate Composites Modified With Copper Nanoparticles on Astralenes

ABSTRACT This study presents photopolymerized nanocomposites based on magnesium phthalocyanine and acrylates (MgPc‐Acr) modified with astralenes (Astr) or copper nanoparticles on astralenes (CuNPs/Astr) for optical recording. Infrared (IR) spectroscopy revealed that while MgPc retards initial polymerization via light competition and radical scavenging, Astr and CuNPs/Astr mitigate this effect. The CuNPs/Astr filler shortened the induction period, achieving 73.5% final conversion (neat reference: 78.7%), balancing processability and properties. Spectrophotometry and scanning electron microscopy (SEM) confirmed a morphology‐optics correlation: unlike MgPc aggregates or dense Astr agglomerates, CuNPs/Astr ensured uniform dispersion without macroscopic clustering. This facilitated an H‐ to J‐aggregate transition, yielding the smallest band gap (1.069 eV), Urbach energy (0.293 eV), and maximum light penetration (~450 μm). Mechanical testing showed balanced elasticity from improved filler distribution. Practical applicability was demonstrated via mask‐based periodic structure formation. Ultimately, the PBI‐MgPc‐CuNPs/Astr composite provides enhanced optical transparency and uniform dispersion, making it promising for fiber optics and additive manufacturing requiring uniform curing and near‐IR (NIR) response.