非晶固体高分子表面的低温流动特性

高分子低温加工是材料领域重大挑战。相较于本体分子，位于材料表面高分子链的玻璃化转变温度降低、黏度减小、塑性增强，为高分子材料低温加工提供了可能途径。本文总结了近年来对非晶固体高分子表面分子运动的研究成果，从表面分子动力学的角度阐述了高分子表面低温流动性的起源及其影响因素，举例介绍了表面低温流动特性在高分子材料低温粘结、自愈合以及加工成型等方面的应用，并对未来研究及前景进行了展望。希望通过本文加深对高分子表面低温流动行为的认识和理解，促进高分子材料加工和成型新方法和新概念的发展。

Low-Temperature Mobility at Surfaces of Amorphous Polymeric Solids

Low-temperature processing of polymer materials is a technological challenge in the field of materials science and engineering. Compared with the molecules in the bulk, polymers chains at the surfaces have depressed glass transition temperature, reduced viscosity, enhanced plasticity, as well as increased ability to be deformed and flow at reduced temperatures, thus providing unique insights into low-temperature processing of polymer materials. In this paper, we summarized the recent research advances on the surface molecular motion of amorphous polymer materials and discussed the origin of the enhanced surface mobility at a low temperature. Moreover, we elaborated the exploration of exploiting the enhancement of low-temperature mobility at polymeric surfaces to enhance cold bonding, self-healing and low-temperature processing of polymer materials. This paper is helpful in deepening our understanding of the polymer surface chain dynamics and could inspire further works to enhance the processability of polymer materials at a reduced low-temperature through well harnessing of the surface mobility.