Impact of different types of treated nanoclays on physico-mechanical, thermal and antibacterial properties of EPDMgMA nanocomposites

Fabricating superior crosslinked nanocomposites from ethylene propylene diene rubber-grafted maleic anhydride (EPDMgMA) and artificial nanoclays is of highest priority; it is important for catering to the market tire needs, and for ensuring vehicle safety and a clean environment. Therefore, the wider aim of this research was to prepare two different kinds of treated nanoclays to be incorporated inside purified EPDMgMA rubber; the resulting high compact networks (EP nanocomposites) can be applied for sustainable automotive tires and other promising applications. Inorganic montmorillonite (MMT) was progressively treated by hexadecyltrimethylammonium bromide (C19TAB) to obtain OMMT1 and OMMT4, and thoroughly investigated by XRD, FTIR, and TGA/DTG techniques. Their outcomes manifested that the d-spacing distance increased to 1.98 nm and 4.40 nm for OMMT1 and OMMT4, respectively, compared to pristine MMT (i.e. 1.62 nm). The TGA/DTG results for OMMT4 revealed that the chemisorbed species (C19TA+) were more thermally stable than the physiosorbed species (C19TAB) in the clay galleries. Pristine and treated clays were incorporated inside EPDMgMA at a fixed quantity of 5 wt.% in the presence of dicumyl peroxide (DCP). The net produced mixes were subjected to various tests like XRD, DSC, TEM, DMA, mechanical, and thermogravimetric analysis. DSC revealed that the crosslinking degree was suppressed in the EP-MMT-5% because of the acidic character of pristine MMT compared to other nanocomposite matrices. However, in all cases, the use of EP matrices-based OMMT1 and OMMT4 improved the morphological and physico-mechanical properties of EP nanocomposites; the exception was thermal stability as measured from TGA analysis, which significantly increased for EP-OMMT4-5%, particularly the degradation onset temperature (T0.5). EP-OMMT4-5% also showed strong antibacterial activity against E. coli compared to other networks.