As a popular “green” engineering plastic, stereocomplex-type polylactide (SC-PLA) exhibits great application potential in various fields owing to its outstanding physicochemical performance and durability. However, the applications of SC-PLA still face formidable challenges mostly associated with its inferior melt-processability (i.e., the weak melt memory effect to motivate exclusive SC crystallization and extremely low melt viscosity) and the lack of necessary functional features (e.g., electrical conductivity) in some cases. Herein, we devise a facile and robust strategy to overcome these obstacles by incorporating carbon black (CB) into equimolar poly(L-lactide)/poly(D-lactide) (PLLA/PDLA) blend. It is interesting to find that the CB particles can adsorb many PLLA/PDLA chain segments on their surface and such strongly adsorbed PLA segments could interact with PLA chains outside the surface to form physical junctions capable of stabilizing the PLLA/PDLA chain assemblies in the melt, finally inducing the exclusive SC formation during subsequent crystallization. Meanwhile, the CB particles can substantially enhance the melt viscosity of the blend (from 3.9 Pa s to 844.1 Pa s when measuring at 250 °C and 50 Hz). Because of the greatly improved melt-processability, the PLLA/PDLA/CB composites have been successfully processed into highly crystalline products with exclusive SC crystallites and excellent thermomechanical performance by injection molding. Additionally, the CB particles can endow the composite products with fascinating electrical conductivity (19.0 S/m) and electromagnetic interference shielding effectiveness (26.6 dB). This work could open up a promising avenue towards high-performance and multifunctional PLA engineering Bioplastic.

立体复合型聚乳酸（SC-PLA）作为一种流行的“绿色”工程塑料，由于其出色的理化性能和耐用性，在各个领域都具有巨大的应用潜力。然而，SC-PLA的应用仍然面临着巨大的挑战，主要与它的熔融加工性差（即，弱的熔体记忆效应导致独有的SC结晶和极低的熔体粘度）以及缺乏必要的功能特性（例如，电学性能）有关。电导率）。本文中，我们设计了一种灵活而强大的策略来克服这些障碍，方法是将炭黑（CB）掺入等摩尔的聚（L-丙交酯）/聚（D-丙交酯）（PLLA / PDLA）共混物中。有趣的是，CB颗粒可在其表面吸附许多PLLA / PDLA链段，而这种吸附力强的PLA链段可与表面外的PLA链相互作用，形成能够稳定熔体中PLLA / PDLA链组件的物理连接。 ，最终在随后的结晶过程中诱导了独有的SC形成。同时，CB颗粒可以显着提高共混物的熔体粘度（在250°C和50 Hz下测量时，从3.9 Pa s到844.1 Pa s）。由于极大地改善了熔融加工性能，PLLA / PDLA / CB复合材料已成功通过注塑成型加工成具有独特的SC微晶和出色的热机械性能的高度结晶的产品。此外，CB颗粒可以使复合产品具有引人入胜的电导率（19.0 S / m）和电磁干扰屏蔽效果（26.6 dB）。这项工作可以为高性能和多功能的PLA工程生物塑料开辟一条有希望的途径。