Effect of Soft Segment Structures on the Properties of Self‐Healing Photopolymerizable Thiocarbamate‐Based Polyurethanes

ABSTRACT Three self‐healing photopolymerizable thiocarbamate‐based polyurethane oligomers were synthesized using different macromolecular chain extenders: polypropylene glycol (PPG‐1000), polytetrahydrofuran (PTMG‐1000), and polycaprolactone glycol (PCL‐1000). The variations in the soft segment structures had minimal impact on the double bond conversion and gel fraction of the light‐cured self‐healing thiocarbamate‐based polyurethane materials, achieving double bond conversion rates and gel fractions exceeding 87%. Incorporating polycaprolactone diol as the soft segment improved heat resistance and tensile stress but reduced the material's self‐healing ability. Conversely, utilizing polytetrahydrofuran as the soft segment resulted in outstanding overall performance, notably lowering the glass transition temperature to −48.4°C, increasing tensile strain to 1280%, achieving a self‐healing efficiency of up to 90%, and exhibiting good degradation properties.