The effect of a micro-crystalline ZnO with columnar structure on the crystallization behavior and mechanical properties of poly(ethylene 2,6-naphthalate)

Abstract

In this study, we synthesized a type of microcrystalline H-ZnO_c with columnar structure by controlling the solubility of the reaction solution. Poly(ethylene 2,6-naphthalate) (PEN) and hexagonal zinc oxide column (H-ZnO_c) composite materials were prepared by a twin screw extruder and the properties of the composites were characterized. The results showed that H-ZnO_c has a remarkable nucleation effect on PEN, especially when the loading amount of H-ZnO_c is 1.5 wt%; the nucleation efficiency is as high as 52.28%, and the crystallization temperature increased by nearly 23 °C. The crystal morphology changed, with the disappearance of the cold crystallization peak after the addition of H-ZnO_c, the size of spherulites decreased and the number of spherulites increased. During the isothermal crystallization process, H-ZnO_c significantly reduced the crystallization time of PEN. The impact strength of PEN increased from 1.86 kJ m⁻² to 2.73 kJ m⁻². Our results showed that H-ZnO_c can be used as an effective nucleating agent for PEN, effectively improving the crystallization ability and mechanical properties, and its performance is comparable to the proprietary polymer nucleating agents NX8000, HPN68L, and TMB-5, etc.