Investigating the Crystallization Kinetics and Mechanical Properties of Poly(Butylene Succinate): The Dual Role of Polyoxymethylene Blending and MWCNT Heterogeneous Nucleation

This study investigates the crystallization behavior of poly(butylene succinate) (PBS) through blending with highly crystalline polyoxymethylene (POM) to address the inherently slow crystallization rate of PBS. The non-isothermal crystallization kinetics of the individual constituents within the blend systems were systematically investigated to elucidate their crystallization behavior under cooling conditions. In addition, the influence of multi-walled carbon nanotube (MWCNT) incorporation on the mechanical, thermomechanical, and morphological properties of PBS/POM blends was evaluated. The crystallization behavior was analyzed using kinetic approaches under non-isothermal conditions. Spherulite morphology was observed via polarized optical microscopy equipped with a controlled heating–cooling stage to elucidate spherulitic development. Scanning electron microscopy (SEM) revealed no obvious micron-scale phase separation in the PBS/POM blends, while the distinct crystallization behavior of the PBS and POM phases observed by differential scanning calorimetry (DSC) indicated that the two components retained their individual crystalline phases, supporting the partial miscibility of the blends. In the ternary systems, SEM observations showed a relatively uniform distribution of MWCNTs at the spatial scale accessible by SEM, with no pronounced micron-scale agglomerates readily discernible within the examined regions. Mechanical analyses demonstrated that the incorporation of MWCNTs enhanced the properties of the blends, particularly the elastic modulus and tensile strength. Kinetic analysis further indicated that MWCNTs influenced the crystallization behavior of the PBS and POM phases through nucleation effects, with their influence depending on the PBS/POM blend composition.