Mechanical and thermal properties of coal gasification fine slag reinforced low density polyethylene composites

Coal gasification fine slag (CGFS) was processed via a grading technique. The CGFS products (CGFS‐S1, CGFS‐S2, CGFS‐S3) with different sizes were obtained. Effects of particle size and unburned carbon on tensile properties of filled low density polyethylene (LDPE) were studied within the CGFS weight fractions ranging from 10 to 50 wt %. The tensile strength was found to increase with decreasing CGFS size, and the tensile properties exhibited good performance, owing to unburned carbon. The tensile strength of the composites increased with increasing CGFS‐S3 weight fraction. The analysis of mathematical model and SEM revealed that the firm improvement of tensile strength resulted from the strong interactions between LDPE polymer chains and CGFS‐S3 particles, and good dispersion of CGFS‐S3 in resin. Thermogravimetric analysis proved obvious reinforcement in thermal‐oxidative stability by incorporation of CGFS‐S3. The degree of crystallinity of LDPE/CGFS‐S3 showed the first increased and then decreased variation tendency. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46203.