Ewurum Nnaemeka, McDonald Armando G
Department of Forest and Fire Sciences, University of Idaho, Moscow, ID 83844-1132, USA.
Polymers (Basel). 2025 Jan 14;17(2):194. doi: 10.3390/polym17020194.
This study investigated the valorization of industrial lignin for producing biodegradable polybutylene succinate (PBS)-lignin copolymers. PBS was blended with varying lignin contents (0-45 wt. %) and crosslinked/grafted using dicumyl peroxide (DCP). The preparation of the copolymers by reactive extrusion was successful, with mechanical, thermal, and morphological properties comprehensively analyzed. Lignin addition decreased tensile strength but improved stiffness (modulus) and thermal stability. Crosslinking with DCP improved the interfacial adhesion between PBS and lignin, resulting in better flexural performance at moderate lignin levels. Differential scanning calorimetry showed that lignin initially improved the crystallization temperature, but hindered it at higher concentrations due to its rigid, aromatic structure. Scanning electron microscopy analysis showed poor interfacial adhesion in PBS-lignin blends, but the surface morphology improved in crosslinked PBS-lignin copolymers, with less phase separation observed. An optimal lignin concentration appeared to depend on the property of interest. While 30% lignin provided the best improvement in flexural strength, 20% lignin offered a more balanced enhancement for most properties without the severe reduction in tensile strength observed at higher lignin contents.
本研究探讨了工业木质素在生产可生物降解聚丁二酸丁二醇酯（PBS）-木质素共聚物方面的价值。将PBS与不同木质素含量（0-45 wt.%）进行共混，并用过氧化二异丙苯（DCP）进行交联/接枝。通过反应挤出成功制备了共聚物，并对其机械、热学和形态学性能进行了全面分析。添加木质素会降低拉伸强度，但会提高硬度（模量）和热稳定性。用DCP交联改善了PBS与木质素之间的界面粘附性，在中等木质素含量下产生了更好的弯曲性能。差示扫描量热法表明，木质素最初提高了结晶温度，但由于其刚性芳香结构，在较高浓度下会阻碍结晶。扫描电子显微镜分析表明，PBS-木质素共混物中的界面粘附性较差，但交联的PBS-木质素共聚物的表面形态有所改善，相分离较少。最佳木质素浓度似乎取决于所关注的性能。虽然30%的木质素能使弯曲强度得到最佳改善，但20%的木质素对大多数性能的增强更为平衡，且不会像在较高木质素含量下那样导致拉伸强度严重降低。
