This study concerns the effect of ultraflow (UTF) content on the thermal property; thermo-oxidation and photo thermal-humidity stability of composites based on high density polyethylene (HDPE) and modified fly ash (MFA). The different scanning calorimeter analysis (DSC) results show that the relative crystallinity of HDPE/MFA and HDPE/MFA/UTF composites is lower than that of HDPE. The thermal properties of HDPE/MFA/UTF composites were studied by using thermogravimetric analysis (TGA) characteristic. | Vietnam Journal of Chemistry, International Edition, 55(6): 709-714, 2017 DOI: Thermal properties, thermo-oxidation and UV-thermo-humidity complex stability of polyethylene/modified fly ash/ultraflow composites Nguyen Thuy Chinh, Nguyen Thi Thu Trang, Tran Thi Mai, Nguyen Vu Giang, Tran Huu Trung, Mai Duc Huynh, Thai Hoang* Institute for Tropical Technology, Vietnam Academy of Science and Technology Received 3 October 2016; Accepted for publication 29 December 2017 Abstract This study concerns the effect of ultraflow (UTF) content on the thermal property; thermo-oxidation and photo thermal-humidity stability of composites based on high density polyethylene (HDPE) and modified fly ash (MFA). The different scanning calorimeter analysis (DSC) results show that the relative crystallinity of HDPE/MFA and HDPE/MFA/UTF composites is lower than that of HDPE. The thermal properties of HDPE/MFA/UTF composites were studied by using thermogravimetric analysis (TGA) characteristic. Thermal stability of HDPE/MFA/UTF composites is higher than HDPE and HDPE/MFA composite. The tensile properties (tensile strength, elongation at break and Young’s modulus) of the composites after thermal aging test had a tendency to reduce with increasing the UTF contents. The retention of tensile strength and Young’s modulus of HDPE/MFA/UTF composites is larger than that of HDPE/MFA composite while the elongation at break of HDPE/MFA/UTF composites is less than that of HDPE/MFA composite. The results of accelerated weathering test showed that the tensile strength, elongation at break and Young’s modulus of HDPE/MFA/UTF composites after 168 hour accelerated weathering test were increased much higher than those of HDPE/MFA composites. Keywords. Ultraflow, thermal property, thermal oxidation, accelerated weathering test, HDPE composite. 1. INTRODUCTION Annually, the thermal power plants have discharged large amounts of fly ash (FA), which caused environmental pollution,
