Electrostatically Assembled Composite Filler for Enhanced Strength and Heat Resistance of
PA6
Rongrong Shen, Junjie Ge, Jing Zhou, Haihong Ma, Zhengfa Zhou, Weibing Xu, Fengmei Ren ABSTRACT
Owing to its high strength and lightweight characteristics, polyamide 6 (PA6) is widely used in the field of engineering plastics. However, the relatively low heat deflection temperature (HDT) of PA6 constrains its application in high‐temperature environments, particularly in electric vehicle charging infrastructure and related functional components. In this study, a composite filler with high surface roughness was prepared by combining sepiolite (SEP) fibers and nano‐montmorillonite (MMT) via a simple, environmentally friendly physical electrostatic adsorption method. Modified composite filler was prepared via surface treatment with the silane coupling agent. The composite materials were prepared through melt compounding with PA6, with a maleic anhydride grafted ethylene‐based elastomer used as a compatibilizer. Compared with composites reinforced with the modified single SEP filler, those prepared with the modified composite filler exhibited significantly improved thermal and mechanical properties. When the nano‐montmorillonite content was 1.5 wt%, the HDT of the composite containing SEPM‐1.5 reached 172°C, which was 24°C higher than that of the composite containing only SEP, while the flexural strength and flexural modulus reached 145 and 5200 MPa, which increased by 31% and 38%, respectively. Non‐isothermal crystallization kinetics analysis revealed that the micro‐nano composite structure of SEP and MMT accelerated the ordered arrangement of PA6 molecular chains through heterogeneous nucleation, significantly increased the crystallization rate, and thus improved the material properties.