Effects of EPDM‐g‐MAH compatibilizer and internal mixer processing parameters on the properties of NR/EPDM blends: An analysis using response surface methodology

Abstract

ABSTRACTThis study evaluates the effects of ethylene‐propylene‐diene‐monomer grafted maleic anhydride (EPDM‐g‐MAH) and internal mixer melt compounding processing parameters on the properties of natural rubber/ethylene‐propylene‐diene rubber (NR/EPDM) blends. Using Response Surface Methodology (RSM) of 25 two‐level fractional factorial, we studied the effects of NR/EPDM ratio, mixing temperature, Banbury rotor speed, mixing period, and EPDM‐g‐MAH contents in NR/EPDM blends. The study found that the presence of EPDM‐g‐MAH in NR/EPDM blends had a predominant role as a compatibilizing agent, which affected the processability and properties of the final material. We also determined the model fitting with constant determination, R2 of 99.60% for tensile strength (TS) response with a suggested combination of mixing process input parameters. The reproducibility of the proposed mixing strategy was then confirmed through model validation with a minor deviation at +2.303% and higher desirability of 0.960. This study is essential in providing a process design reference for NR/EPDM blends preparation by melt‐blending and the role of a compatibilizer from the systematic Design of Experiment (DOE) approach. The experimental findings were further supported with swelling and cross‐link density measurements, differential scanning calorimetry analysis, and observation of fracture morphology using a scanning electron microscope. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42199.