Bujok Sonia, Hodan Jiří, Beneš Hynek
Institute of Macromolecular Chemistry, CAS, Heyrovského nám. 2, 162 06 Prague 6-Břevnov, Czech Republic.
Nanomaterials (Basel). 2020 May 18;10(5):969. doi: 10.3390/nano10050969.
The high capacity of calcinated layered double hydroxides (LDH) to immobilize various active molecules together with their inherent gas/vapor impermeability make these nanoparticles highly promising to be applied as nanofillers for biodegradable polyester packaging. Herein, trihexyl(tetradecyl)phosphonium decanoate ionic liquid (IL) was immobilized on the surface of calcinated LDH. Thus, the synthesized nanoparticles were used for the preparation of polycaprolactone (PCL)/LDH nanocomposites. Two different methods of nanocomposite preparation were used and compared: microwave-assisted in situ ring opening polymerization (ROP) of -caprolactone (CL) and melt-blending. The in situ ROP of CL in the presence of LDH nanoparticles with the immobilized IL led to homogenous nanofiller dispersion in the PCL matrix promoting formation of large PCL crystallites, which resulted in the improved mechanical, thermal and gas/water vapor barrier properties of the final nanocomposite. The surface-bonded IL thus acted as nanofiller surfactant, compatibilizer, as well as thermal stabilizer of the PCL/LDH nanocomposites. Contrary to that, the melt-blending caused a partial degradation of the immobilized IL and led to the production of PCL nanocomposites with a heterogenous nanofiller dispersion having inferior mechanical and gas/water vapor barrier properties.
煅烧层状双氢氧化物（LDH）固定各种活性分子的能力很强，且具有固有的气体/蒸汽不渗透性，这使得这些纳米颗粒作为可生物降解聚酯包装的纳米填料具有很大的应用前景。在此，将癸酸三己基（十四烷基）鏻离子液体（IL）固定在煅烧LDH的表面。因此，所合成的纳米颗粒被用于制备聚己内酯（PCL）/LDH纳米复合材料。使用并比较了两种不同的纳米复合材料制备方法：己内酯（CL）的微波辅助原位开环聚合（ROP）和熔融共混。在具有固定化IL的LDH纳米颗粒存在下CL的原位ROP导致纳米填料在PCL基体中均匀分散，促进了大尺寸PCL微晶的形成，这使得最终纳米复合材料的机械、热和气体/水蒸气阻隔性能得到改善。因此，表面键合的IL充当了PCL/LDH纳米复合材料的纳米填料表面活性剂、增容剂以及热稳定剂。与此相反，熔融共混导致固定化IL部分降解，并导致制备出纳米填料分散不均匀、机械和气体/水蒸气阻隔性能较差的PCL纳米复合材料。
