Pal Akhilesh Kumar, Bhasney Siddharth Mohan, Bhagabati Purabi, Katiyar Vimal
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Kamrup, Assam, India.
ACS Omega. 2018 Oct 16;3(10):13298-13312. doi: 10.1021/acsomega.8b00907. eCollection 2018 Oct 31.
Nanobiocomposites with balanced mechanical characteristics are fabricated from poly(lactic acid) (PLA)/poly(butylene succinate) (PBS)blend at a weight ratio of 80/20 in association with varying concentrations of functionalized chitosan (CH) through reactive extrusion at a temperature of 185 °C. The combined effect of CH and dicumyl peroxide (DCP) showed insignificant change in tensile strength with a remarkable increase in % elongation at break (∼45%) values. Addition of DCP also caused increase in the molecular weight ( ∼ 22%) of the PLA/PBS/1DCH nanobiocomposite, which is attributed to the cross-linking/branching effect of CH on the polymers. The interfacial polymer-filler adhesion is also improved, which is observed from the field-emission scanning electron microscopy images of PLA/PBS/1DCH. For PLA/PBS/1DCH, the crystallization rate and nucleation density of PLA are increased because of cross-linked/branched structures are developed, which acted as nucleating sites. Therefore, the present work facilitates a simple extrusion processing with a combination of balanced thermal and mechanical properties, improved hydrophobicity (∼27%), and UV-C-blocking efficiency, which draw the possibility for the utilization of the ecofriendly nanobiocomposite in the packing of UV-sensitive materials on a commercial level.
通过在185°C的温度下进行反应挤出，以80/20的重量比由聚乳酸（PLA）/聚丁二酸丁二醇酯（PBS）共混物与不同浓度的功能化壳聚糖（CH）制备出具有平衡机械性能的纳米生物复合材料。CH和过氧化二异丙苯（DCP）的联合作用使拉伸强度变化不显著，但断裂伸长率（约45%）值显著增加。DCP的添加还导致PLA/PBS/1DCH纳米生物复合材料的分子量增加（约22%），这归因于CH对聚合物的交联/支化作用。从PLA/PBS/1DCH的场发射扫描电子显微镜图像可以观察到，聚合物与填料之间的界面粘附性也得到了改善。对于PLA/PBS/1DCH，由于形成了交联/支化结构作为成核位点，PLA的结晶速率和成核密度增加。因此，目前的工作促进了一种简单的挤出加工，该材料具有平衡的热性能和机械性能、改善的疏水性（约27%）以及紫外线C阻挡效率，这为在商业层面将这种环保纳米生物复合材料用于包装对紫外线敏感的材料提供了可能性。
