Abstract Poly(propylene carbonate) (PPC) is a new attractive biodegradable polymers synthesized from inexhaustible carbon dioxide and propylene epoxide, but shows low glass transition temperature (Tg) and poor mechanical properties, which greatly limits its practical applications and industrialization development. To improve Tg and the practicability of PPC, in this work, graphite nanoplates-spherical nanocrystalline cellulose (GNP-SNCC) hybrids, which were bonded by both physical and chemical forces, were prepared by ball milling from graphite and microfibrillated cellulose, and the structure formation as well as properties of PPC/GNP-SNCC composites were studied. The results showed that the improved interfacial interactions between GNP-SNCC and PPC, and the rigid two-dimensional structure of GNP-SNCC were beneficial for the constraint of PPC molecular chains, thus significantly improving Tg and the mechanical properties of PPC matrix, e.g. Tg increased from 34.0 °C of neat PPC to 51.3 °C, and the yield strength increased from 27 MPa to 52.8 MPa. Moreover, facilitated by SNCC, a conductive pathway of GNP was effectively constructed, leading to the great increase in the electrical conductivity of PPC/GNP-SNCC composite. The composite with 10 wt% (5.71 vol%) graphite showed 9 orders of magnitude higher than that of PPC/graphite composite with the same graphite content, and the percolation threshold was drastically decreased from 15 to 5 wt% (8.56–2.85 vol%).

中文翻译：

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具有改进玻璃化转变温度和电导率的聚（碳酸丙二酯）/石墨纳米片-球形纳米晶纤维素复合材料的制备

摘要 聚碳酸亚丙酯（PPC）是一种以取之不尽的二氧化碳和环氧丙烷为原料合成的新型有吸引力的可生物降解聚合物，但其玻璃化转变温度（Tg）低、力学性能差，极大地限制了其实际应用和产业化发展。为了提高Tg和PPC的实用性，在这项工作中，石墨和微纤化纤维素通过球磨制备了通过物理和化学力结合的石墨纳米片-球形纳米晶纤维素（GNP-SNCC）杂化物，其结构研究了 PPC/GNP-SNCC 复合材料的形成和性能。结果表明，GNP-SNCC 和 PPC 之间改善的界面相互作用，GNP-SNCC 的刚性二维结构有利于 PPC 分子链的约束，从而显着提高了 PPC 基体的 Tg 和力学性能，例如 Tg 从纯 PPC 的 34.0°C 增加到 51.3°C，并且屈服强度从 27 MPa 增加到 52.8 MPa。此外，在 SNCC 的促进下，有效地构建了 GNP 的导电通路，导致 PPC/GNP-SNCC 复合材料的电导率大大提高。含有 10 wt% (5.71 vol%) 石墨的复合材料比具有相同石墨含量的 PPC/石墨复合材料高 9 个数量级，并且渗透阈值从 15 wt% (8.56–2.85 vol%) 急剧下降）。3 °C，屈服强度从 27 MPa 增加到 52.8 MPa。此外，在SNCC的促进下，有效地构建了GNP的导电通路，导致PPC/GNP-SNCC复合材料的电导率大大提高。含有 10 wt% (5.71 vol%) 石墨的复合材料比具有相同石墨含量的 PPC/石墨复合材料高 9 个数量级，并且渗透阈值从 15 wt% (8.56–2.85 vol%) 急剧下降）。3 °C，屈服强度从 27 MPa 增加到 52.8 MPa。此外，在SNCC的促进下，有效地构建了GNP的导电通路，导致PPC/GNP-SNCC复合材料的电导率大大提高。含有 10 wt% (5.71 vol%) 石墨的复合材料比具有相同石墨含量的 PPC/石墨复合材料高 9 个数量级，并且渗透阈值从 15 wt% (8.56–2.85 vol%) 急剧下降）。