Influence of Filler from a Renewable Resource and Silane Coupling Agent on the Properties of Epoxidized Natural Rubber Vulcanizates

Table 3

Chemical compositions of RHA.

Chemical composition	Concentration (%)
Silicon dioxide (SiO2)	91.04
Potassium oxide (K2O)	3.70
Phosphorus pentoxide (P2O5)	1.36
Calcium oxide (CaO)	1.96
Magnesium oxide (MgO)	0.45
Alumina (Al2O3)	0.52
Iron oxide (Fe2O3)	0.60
Manganese oxide (MnO)	0.32
Barium oxide (BaO)	0.03
Lead oxide (PbO)	0.05
Rubidium oxide (Rb2O)	0.02