A Comparative Study on the Morphology, Structure, and Thermal Behavior of Polybutylene Succinate and Polycaprolactone Biopolymer Blends with Eucomis autumnalis Cellulose

Abstract

Development of biodegradable polymer composites provides a sustainable alternative to conventional plastics. This study systematically investigates the effect of <i>Eucomis autumnalis</i> (EA) cellulose on the morphological, structural, and thermal behavior of polybutylene succinate (PBS) and polycaprolactone (PCL) blends. EA cellulose was extracted via delignification and hemicellulose removal, yielding 38% cellulose from the leaf biomass. A series of PBS/PCL/EA cellulose composites were prepared using a solution-casting method. Fourier-transform infrared spectroscopy (FTIR) confirmed retention of characteristic functional groups, with spectra dominated by PCL features, indicating the absence of new chemical bond formation between EA cellulose and the polymer matrix. X-ray powder diffraction (XRPD) revealed that EA cellulose acted as a nucleating agent, enhancing the crystallinity, especially in PCL, while slightly affecting PBS crystallization. A scanning electron microscopy (SEM) analysis demonstrated preferential localization of EA cellulose within the PBS phase, contributing to improved phase dispersion and interfacial interaction at the morphological level. Differential scanning calorimetry (DSC) showed enhanced crystallization behavior of PCL at higher EA cellulose loading (5 wt.%), with minimal influence on PBS thermal transitions. A thermogravimetric analysis (TGA) indicated that the thermal stability depends on the polymer composition and cellulose content, with higher PCL fractions contributing to an improved stability. This study provides insight into the structure-property relationships governing PBS/PCL/EA cellulose systems and highlights the potential of EA cellulose as a bio-based additive for tailoring morphological and thermal characteristics of biodegradable polymer blends. A mechanical performance evaluation is recommended for future studies to correlate structural modifications with macroscopic properties.