Sanaka Rajita, Sahu Santosh Kumar, Sreekanth P S Rama, Giri Jayant, Mohammad Faruq, Al-Lohedan Hamad A, Saharudin Mohd Shahneel, Ma Quanjin
School of Mechanical Engineering, VIT-AP University, Besides A.P. Secretariat, Amaravati 522237, Andhra Pradesh, India.
Department of Mechanical Engineering, Yeshwantrao Chavan College of Engineering, Nagpur 441110, Maharashtra, India.
Polymers (Basel). 2025 Jan 26;17(3):338. doi: 10.3390/polym17030338.
This study investigates the fabrication and characterization of heat-responsive PLA/PU/MXene shape memory polymer blend nanocomposites with varying PLA content (10, 20, 30, and 50%) and a fixed MXene content of 0.5 wt.%. The results indicate significant improvements in mechanical properties, with the 50% PLA/PU/MXene blend showing a 300% increase in ultimate tensile strength and a 90% decrease in % elongation compared to pure PU. Additionally, the 50% blend exhibited a 400% increase in flexural strength. Microstructural analysis revealed dispersed pores and sea-island morphology in pure PU and the 50% PLA/PU/MXene blend. Thermal analysis using DSC showed an increase in crystallinity from 33% (pure PU) to 45% for the 50% PLA/PU/MXene blend, indicating enhanced crystalline domains due to the semi-crystalline nature of PLA and MXene's influence on molecular ordering. TGA demonstrated a significant improvement in thermal stability, with the onset temperature rising from 185 °C (pure PU) to 212 °C and the degradation temperature increasing from 370 °C to 425 °C for the 50% blend, attributed to the rigid structure of PLA and MXene's stabilizing effect. Shape memory testing revealed that the 30% PLA/PU/MXene blend achieved the best shape fixity and recovery with optimal performance, whereas higher PLA content diminished shape memory behavior.
本研究调查了具有不同聚乳酸（PLA）含量（10%、20%、30%和50%）以及固定的0.5 wt.% 碳化钛铝碳（MXene）含量的热响应性聚乳酸/聚氨酯/碳化钛铝碳形状记忆聚合物共混纳米复合材料的制备与表征。结果表明，材料的机械性能有显著改善，与纯聚氨酯相比，50%聚乳酸/聚氨酯/碳化钛铝碳共混物的极限拉伸强度提高了300%，伸长率降低了90%。此外，50%的共混物弯曲强度提高了400%。微观结构分析显示，纯聚氨酯和50%聚乳酸/聚氨酯/碳化钛铝碳共混物中存在分散的孔隙和海岛形态。使用差示扫描量热法（DSC）进行的热分析表明，50%聚乳酸/聚氨酯/碳化钛铝碳共混物的结晶度从33%（纯聚氨酯）提高到了45%，这表明由于聚乳酸的半结晶性质以及碳化钛铝碳对分子有序性的影响，结晶区域得到了增强。热重分析（TGA）表明热稳定性有显著提高，50%共混物的起始温度从185℃（纯聚氨酯）升至212℃，降解温度从370℃升至425℃，这归因于聚乳酸的刚性结构和碳化钛铝碳的稳定作用。形状记忆测试表明，30%聚乳酸/聚氨酯/碳化钛铝碳共混物实现了最佳的形状固定性和恢复性能，而较高的聚乳酸含量会降低形状记忆行为。
