El-Taweel Safaa H, Sanad Sherif M H, Mekky Ahmed E M
Chemistry Department, Faculty of Science, Cairo University Orman-Giza 12613 Egypt
Engineering and Materials Science Department, German University in Cairo New Cairo City Egypt.
RSC Adv. 2025 Apr 28;15(17):13539-13551. doi: 10.1039/d5ra00368g. eCollection 2025 Apr 22.
This study evaluates the modification of biodegradable poly(l-lactide) (PLLA) using a novel organic nucleating agent, 2,2'-(butane-1,4-diylbis(oxy))di(benzohydrazide) (BDOBH) with a low concentration range from (0.3-3 wt%). The novelty of this work lies in the development and application of BDOBH as a highly efficient, low-loading organic nucleator tailored to improve PLLA's crystallization behavior and thermal properties-key limitations in its broader industrial use. The evaluation is conducted through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and polarized optical microscopy. FTIR analysis reveals the presence of H-bonding interaction between BDOBH and PLLA. DSC results significantly improve PLLA's crystallization rate, with BDOBH in a concentration range from 0.3 to 0.7 wt%. The total crystallinity of PLLA increases from 12% to 56-60% without a change in PLA's crystallography; moreover, the maximum temperature of the cold crystallization peak shifts to a lower value by 35 °C after incorporating BDOBH-0.7 into PLLA. POM results reveal a drastic decrease in the spherulitic size of PLLA. Furthermore, the presence of BDOBH enhances the thermal stability of PLLA. The nonisothermal cold crystallization behavior of PLLA nucleated by BDOBH is evaluated using the modified Avrami and Mo models. Multiple indicators of nonisothermal crystallization, including the crystallization half-time and crystallization rate constant, indicate that BDOBH greatly expedites the crystallization process. The activation energy values of the plain PLLA and PLLA-BDOBH, as computed using the Kissinger-Akahira-Sunose (KAS) model, decrease when BDOBH is incorporated. These findings highlight BDOBH's potential as a cost-effective and scalable additive to tailor PLLA crystallization, supporting its use in environmentally friendly packaging, biomedical devices, and other high-performance biodegradable applications.
本研究评估了使用新型有机成核剂2,2'-(丁烷-1,4-二基双(氧基))二(苯甲酰肼)(BDOBH)对生物可降解聚(l-丙交酯)(PLLA)进行改性，其浓度范围较低，为(0.3 - 3 wt%)。这项工作的新颖之处在于开发并应用了BDOBH，它是一种高效、低负载的有机成核剂，旨在改善PLLA的结晶行为和热性能，而这正是其在更广泛工业应用中的关键限制因素。通过差示扫描量热法(DSC)、热重分析(TGA)、傅里叶变换红外光谱(FTIR)和偏光显微镜进行评估。FTIR分析揭示了BDOBH与PLLA之间存在氢键相互作用。DSC结果表明，当BDOBH浓度在0.3至0.7 wt%范围内时，PLLA的结晶速率显著提高。PLLA的总结晶度从12%增加到56 - 60%，而PLA的晶体结构没有变化；此外，在将BDOBH - 0.7加入PLLA后，冷结晶峰的最高温度降低了35°C。偏光显微镜结果显示PLLA的球晶尺寸急剧减小。此外，BDOBH的存在增强了PLLA的热稳定性。使用改进的Avrami和Mo模型评估了由BDOBH成核的PLLA的非等温冷结晶行为。包括结晶半衰期和结晶速率常数在内的多个非等温结晶指标表明，BDOBH极大地加速了结晶过程。使用基辛格 - 赤平 - ose (KAS)模型计算的纯PLLA和PLLA - BDOBH的活化能值在加入BDOBH后降低。这些发现突出了BDOBH作为一种经济高效且可扩展的添加剂来调控PLLA结晶的潜力，支持其在环保包装、生物医学设备和其他高性能生物可降解应用中的使用。
