Structure-process-property relationships of acrylonitrile-based copolymers synthesized via emulsion and suspension polymerizations

Acrylonitrile-based copolymers were synthesized via emulsion and suspension polymerization using hydroxypropyl methacrylate (HPMA) and methyl methacrylate (MMA) as comonomers. The influence of polymerization route and comonomer composition on molecular architecture, thermal behavior, and mechanical performance was systematically investigated. Structural characterization was performed by FT-IR and 1H NMR spectroscopy, confirming successful comonomer incorporation and consistency between feed and copolymer compositions. Molecular weight distribution was determined by gel permeation chromatography (GPC), while thermal properties were evaluated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Intrinsic viscosity measurements were additionally conducted to assess solution behavior and processability. Thermal analyses revealed composition-dependent glass transition behavior and thermal stability, whereas single-fiber tensile testing demonstrated a tunable strength-ductility balance governed by comonomer type and composition. The comparative analysis of emulsion and suspension polymerization highlights the critical role of polymerization route in governing molecular architecture, thermal behavior, and mechanical performance. These findings establish clear structure-process-property relationships in acrylonitrile-based copolymers and provide insight into the rational design of PAN-based functional materials for advanced applications.