In this work, 3D printed polylactic acid (PLA)/polycaprolactone (PCL) nanocomposites with favorable thermo-responsive cyclic shape memory effects (SMEs) and crystallization and mechanical properties were fabricated using a two-step method. First, an isocyanate-terminated PCL diol (PCL-NCO) was synthesized through the reaction between isocyanate groups of hexamethylene diisocyanate and active hydroxyl groups of PCL diol, and its physicochemical properties were characterized. A PLA/PCL blend with a PCL content of 50 wt% was fabricated via fused filament fabrication (FFF) 3D printing, and the influence of the PCL-NCO on the SME of the PLA/PCL blend was studied. The results indicated that the PCL-NCO significantly improved the cyclic shape memory performance of 3D printed PLA/PCL blends and was proved to be an effective interface compatibilizer for the blend system. Subsequently, the structure and properties of 3D printed PLA/PCL nanocomposites were investigated in detail by adding cellulose nanocrystal-organic montmorillonite (CNC-OMMT) hybrid nanofillers with different contents. It was found that the hybrid nanofillers greatly enhanced crystallization and mechanical properties of the nanocomposites due to adequate dispersion. The modification of the PLA/PCL blend and the preparation of the 3D printed nanocomposite can not only prolong the service life of a shape memory polymer product, but also broaden its application scope in advanced fields.

中文翻译：

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具有良好热响应循环形状记忆效应、结晶和机械性能的 3D 打印聚乳酸/聚己内酯纳米复合材料的制备

在这项工作中，使用两步法制造了具有良好热响应循环形状记忆效应 (SME) 以及结晶和机械性能的 3D 打印聚乳酸 (PLA)/聚己内酯 (PCL) 纳米复合材料。首先，通过六亚甲基二异氰酸酯的异氰酸酯基团与PCL二醇的活性羟基之间的反应合成了异氰酸酯封端的PCL二醇（PCL-NCO），并对其理化性质进行了表征。通过熔丝制造 (FFF) 3D 打印制造 PCL 含量为 50 wt% 的 PLA/PCL 共混物，并研究了 PCL-NCO 对 PLA/PCL 共混物 SME 的影响。结果表明，PCL-NCO 显着提高了 3D 打印 PLA/PCL 共混物的循环形状记忆性能，并被证明是共混体系的有效界面增容剂。随后，通过添加不同含量的纤维素纳米晶体-有机蒙脱石 (CNC-OMMT) 杂化纳米填料，详细研究了 3D 打印的 PLA/PCL 纳米复合材料的结构和性能。结果发现，由于充分分散，混合纳米填料极大地增强了纳米复合材料的结晶和机械性能。PLA/PCL共混物的改性和3D打印纳米复合材料的制备不仅可以延长形状记忆聚合物产品的使用寿命，还可以拓宽其在先进领域的应用范围。通过添加不同含量的纤维素纳米晶体-有机蒙脱石 (CNC-OMMT) 杂化纳米填料，详细研究了 3D 打印的 PLA/PCL 纳米复合材料的结构和性能。结果发现，由于充分分散，混合纳米填料极大地增强了纳米复合材料的结晶和机械性能。PLA/PCL共混物的改性和3D打印纳米复合材料的制备不仅可以延长形状记忆聚合物产品的使用寿命，还可以拓宽其在先进领域的应用范围。通过添加不同含量的纤维素纳米晶体-有机蒙脱石 (CNC-OMMT) 杂化纳米填料，详细研究了 3D 打印的 PLA/PCL 纳米复合材料的结构和性能。结果发现，由于充分分散，混合纳米填料极大地增强了纳米复合材料的结晶和机械性能。PLA/PCL共混物的改性和3D打印纳米复合材料的制备不仅可以延长形状记忆聚合物产品的使用寿命，还可以拓宽其在先进领域的应用范围。结果发现，由于充分分散，混合纳米填料极大地增强了纳米复合材料的结晶和机械性能。PLA/PCL共混物的改性和3D打印纳米复合材料的制备不仅可以延长形状记忆聚合物产品的使用寿命，还可以拓宽其在先进领域的应用范围。结果发现，由于充分分散，混合纳米填料极大地增强了纳米复合材料的结晶和机械性能。PLA/PCL共混物的改性和3D打印纳米复合材料的制备不仅可以延长形状记忆聚合物产品的使用寿命，还可以拓宽其在先进领域的应用范围。