Arrieta Alvaro A, Calabokis Oriana Palma, Mendoza Jorge Mario
Department of Biology and Chemistry, Universidad de Sucre, Sincelejo 700001, Colombia.
Faculty of Engineering and Basic Sciences, Fundación Universitaria Los Libertadores, Bogota 111221, Colombia.
Polymers (Basel). 2023 Oct 19;15(20):4150. doi: 10.3390/polym15204150.
This study evaluates the effect of lithium salts on the structural, electrochemical, and thermal properties of cassava starch solid biopolymer electrolytes (SBPEs). Films of SBPEs were synthesized using plasticizing agents and lithium salts (LiCl, LiSO, and CFLiSO) via thermochemical method. The SBPEs with lithium salts exhibited characteristic FTIR bands starch, with slight variations in the vibration oxygen-related functional groups compared to salt-free biopolymer spectra. The R index (short-range crystallinity) was higher in the films synthesized without lithium salt and the lowest value was established in the films synthesized with LiSO. Thermal degradation involved dehydration between 40 to 110 °C and molecular decomposition between 245 to 335 °C. Degradation temperatures were close when synthesized with salts but differed in films without lithium salt. DSC revealed two endothermic processes: one around 65 °C linked to crystalline structure changes and the second at approximately 271 °C associated with glucose ring decomposition. The electrochemical behavior of the SBPEs varied with the salts used, resulting in differences in the potential and current of peaks from the redox processes and its conductivity, presenting the lowest value (8.42 × 10 S cm) in the SBPE films without salt and highest value (9.54 × 10 S cm) in the films with LiSO. It was concluded that the type of lithium salt used in SBPEs synthesis affected their properties. SBPEs with lithium triflate showed higher molecular ordering, thermal stability, and lower redox potentials in electrochemical processes.
本研究评估了锂盐对木薯淀粉固体生物聚合物电解质（SBPEs）的结构、电化学和热性能的影响。通过热化学方法，使用增塑剂和锂盐（LiCl、LiSO和CFLiSO）合成了SBPEs薄膜。含锂盐的SBPEs呈现出淀粉特有的傅里叶变换红外光谱（FTIR）谱带，与无盐生物聚合物光谱相比，与氧相关的振动官能团略有变化。不含锂盐合成的薄膜中R指数（短程结晶度）较高，而含LiSO合成的薄膜中该值最低。热降解包括40至110℃之间的脱水以及245至335℃之间的分子分解。用盐合成时降解温度相近，但无锂盐的薄膜降解温度不同。差示扫描量热法（DSC）显示有两个吸热过程：一个在65℃左右，与晶体结构变化有关；另一个在约271℃，与葡萄糖环分解有关。SBPEs的电化学行为随所用盐的不同而变化，导致氧化还原过程中峰电位和电流及其电导率存在差异，无盐的SBPE薄膜电导率最低（8.42×10 S cm），含LiSO的薄膜电导率最高（9.54×10 S cm）。得出的结论是，SBPEs合成中所用锂盐的类型影响其性能。含三氟甲磺酸锂的SBPEs在电化学过程中表现出更高的分子有序性、热稳定性和更低的氧化还原电位。
