Simulation, Synthesis, and Degradation of Thioester-Engineered Polyacrylate Latex

Polyacrylate latex (PA) is widely applied in waterborne inks, but the stable C–C backbone of conventional PA hinders deinking efficiency in paper recycling. To address this challenge, we incorporated dibenzo[c,e]oxepane-5(7H)-thione (DOT) into the PA backbone via radical ring-opening polymerization (rROP), creating a degradable polymer system. Density functional theory (DFT) simulations revealed that butyl acrylate (BA) facilitates ternary copolymerization by bridging DOT and methyl methacrylate (MMA), enabling a statistical distribution of cleavable groups. Emulsion polymerization yielded high-molecular-weight degradable PA (Mn ∼ 300 kg·mol–1) with embedded thioester bonds. The yielded degradable PA polymer cleaved into low-molecular-weight fragments (Mn < 5 kg·mol–1) under mild oxidative conditions, while possessing satisfactory mechanical strength with a maximum tensile strength of up to 7.55 MPa. The resultant ink from the as-prepared degradable PA demonstrated exceptional degradability (95.3% degradation ratio) using only H2O2 treatment, enabling efficient fiber–ink separation. This work establishes a strategy for synthesizing high-performance degradable polymers through facile conventional emulsion polymerization techniques.