A series of ternary thermotropic liquid crystalline copolyesters was synthesized through a simple one-pot melt condensation based on 4-hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA) and 4-hydroxy-2-naphthoic acid (4-HNA). The structures were modified via the introduction of the asymmetric 4-HNA unit. High glass transition temperature values (>80 C) and relatively low melting temperature values (<265 C) were achieved with 4-HNA molar fraction of over 0.5%, and the copolymer exhibited 5% degradation temperatures of 442-453 C and the char yields of 35.80%-36.74% at 800 C. This indicated that the introduction of asymmetric 4-HNA blocks into the backbone provides a "torsion axis" to regulate the dense stacking between different main-chains, which was crucial for the mobility of polyester during thermal processes. Moreover, crystallinity decreased with the increase of 4-HNA content. The incorporation of 4-HNA also endowed the obtained copolyester fiber with a skin-core structure and microfiber morphology. Due to the excellent temperature resistance and fibrous morphology of P-HBA/HNA/4-HNA. This work provided a novel strategy to synthesize aromatic thermotropic liquid crystalline copolyesters, which can be promising candidates for processing additives or reinforcing materials with improved processing properties, and potential application in processing, personal protection, and other extreme temperature environments.

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China has entered into a light aging society and is gradually moving into the moderate aging society stage. A portion of the elderly with indoor transferring difficulties has become the core user of mobility aid design. In order to construct a persona for this relevant population, the data of the elderly in various fields in the CHARLS database from 2018 was sorted, and a hierarchical clustering analysis was conducted using 12 variables of 119 samples. Based on the overall variability of sample variables, the elderly with indoor transferring difficulties in China were classified according to the similarity of their characteristic data. The results of the hierarchical clustering analysis indicated that the elderly with indoor transferring difficulties in China can be divided into seven clusters. By sorting and refining the data of each cluster, seven data-driven personas containing their characteristic labels were obtained. By utilizing the cluster characteristics, the design direction of the mobility aid was determined, and a summary was made of the mobility aid 's functional features and corresponding interactive solutions for the physical needs of the elderly with indoor transferring difficulties in China.