Interaction between silicone and EPDM rubbers through functionalization and its effect on properties of the blend

Abstract

Silicone rubber was functionalized with acrylamide (AM) to effect interaction with sulfonated EPDM. I.r. spectroscopic studies confirm the dipole-dipole interactions between this graft copolymer (AM- g-silicone) and sulfonated EPDM (S-EPDM) through the splitting of the carbonyl stretching and NH stretching peaks. Physical property measurements show that the functionalized blend has a higher tensile strength, modulus and swelling resistance and lower elongation at break. The thermal stability and ageing behaviour of the new blends are improved owing to an increase in the activation energy of degradation. Finally, dynamic measurements show that the transition temperatures are all increased by 8–10°C and the storage modulus in the temperature range 25–125°C is higher, owing to strong interspecies interactions between the components in the functionalized blends.