Kumalo Fisokuhle Innocentia, Malimabe Moipone Alice, Mosoabisane Mafereka Francis Tyson, Gumede Thandi Patricia
Department of Chemistry, University of the Free State, QwaQwa Campus, Private Bag X13, Phuthaditjhaba 9866, South Africa.
Department of Life Sciences, Central University of Technology, Bloemfontein 9301, South Africa.
Polymers (Basel). 2025 Apr 2;17(7):971. doi: 10.3390/polym17070971.
This study investigates the effect of (EA) cellulose on the structural, thermal, and crystallization behaviour of polybutylene succinate (PBS) and polycaprolactone (PCL) composites. X-ray diffraction (XRD) results showed that in both matrices, EA cellulose promoted nucleation, as indicated by increased peak intensity, while differential scanning calorimetry (DSC) showed reduced melting enthalpy, suggesting the formation of smaller, less perfect crystals. In PBS composites, EA cellulose acted as a crystallization disruptor, reducing crystallinity and enthalpy. Moreover, it slightly lowered the melting temperature. This is because EA cellulose contains β-(1→4) glycosidic bonds, which introduce -O- (ether) linkages along its polymer backbone. These linkages allow for a degree of rotational flexibility. When the cellulose is incorporated into PBS, this structural characteristic may contribute to a reduction in , likely by disrupting the crystallization of PBS chains. At 1 wt.% EA cellulose, broader, more intense melting peaks indicated imperfect crystal formation, while higher loadings (3 and 5 wt.%) resulted in narrower, less intense peaks, reflecting reduced crystallinity. These results are consistent with cooling-curve results and SEM images showing structural irregularities. In PCL composites, EA cellulose similarly reduced crystallinity and enthalpy without significantly affecting melting or crystallization temperatures. The decrease in the melting enthalpy from 55.6 J/g to 47.6 J/g suggested the formation of thinner lamellae and less organized crystals, a conclusion supported by stable crystallization temperatures and declining peak intensities in cooling curves. The combination of XRD and DSC data highlighted the dual role of EA cellulose: it enhances nucleation while hindering crystal growth, leading to the formation of more amorphous structures in both PBS and PCL matrices. These findings offer valuable insights into the potential use of EA cellulose as a functional modifier to tailor the properties of biopolymer composites for environmentally friendly, biodegradable applications.
本研究考察了（EA）纤维素对聚丁二酸丁二醇酯（PBS）和聚己内酯（PCL）复合材料的结构、热性能及结晶行为的影响。X射线衍射（XRD）结果表明，在两种基体中，EA纤维素均促进了成核，表现为峰强度增加；而差示扫描量热法（DSC）显示熔融焓降低，表明形成了更小、更不完善的晶体。在PBS复合材料中，EA纤维素起到了结晶破坏剂的作用，降低了结晶度和焓。此外，它还略微降低了熔融温度。这是因为EA纤维素含有β-(1→4)糖苷键，这些键沿其聚合物主链引入了-O-（醚）键。这些键允许一定程度的旋转灵活性。当纤维素掺入PBS中时，这种结构特征可能有助于降低结晶度，可能是通过破坏PBS链的结晶来实现的。在1 wt.%的EA纤维素含量下，更宽、更强的熔融峰表明形成了不完善的晶体，而更高的含量（3 wt.%和5 wt.%）导致峰变窄、强度降低，反映出结晶度降低。这些结果与冷却曲线结果和显示结构不规则的扫描电子显微镜（SEM）图像一致。在PCL复合材料中，EA纤维素同样降低了结晶度和焓，而对熔融或结晶温度没有显著影响。熔融焓从55.6 J/g降至47.6 J/g表明形成了更薄的片晶和组织性更差的晶体，冷却曲线中稳定的结晶温度和下降的峰强度支持了这一结论。XRD和DSC数据的结合突出了EA纤维素的双重作用：它增强成核同时阻碍晶体生长，导致在PBS和PCL基体中形成更多的非晶结构。这些发现为EA纤维素作为功能改性剂用于定制生物聚合物复合材料的性能以实现环境友好、可生物降解应用提供了有价值的见解。
