Radiation‐Induced Property Enhancement in Peroxide‐Cured VMQ Elastomers Using Divinylbenzene as Coagent

ABSTRACT This study indicates how the combination of divinylbenzene (DVB) and ionizing radiation impacts the curing kinetics, cross‐link density, and mechanical and energy‐damping properties of peroxide‐cured vinyl methyl siloxane (VMQ) elastomers. The addition of DVB extended the optimal cure time from 1.70 to 3.42 min at 180°C and increased ΔTorque from 6.59 to 10.50 dNm, signifying improved cross‐link density. Kinetic analysis conducted using the Isayev–Deng model indicated that the activation energy for the DVB‐modified system was lower (187.8 kJ/mol) compared to the unmodified VMQ (224.1 kJ/mol). Cross‐link density measurements revealed that DVB enhanced the chemical cross‐link density from 29.3 to 76.6 mol/cm 3 . Moreover, the presence of DVB resulted in an increase in tensile modulus (from 2.97 to 3.41 MPa) and Shore A hardness (from 46 to 56). After irradiation at 100 kGy, the elastic modulus of the DVB‐containing elastomers increased to 5.92 MPa, and their energy absorption capacity improved from 575.1 to 896.7 mJ/cm 3 . The relative hysteresis loss (tan δ ) stabilized across cycles, indicating improved damping stability. These results affirm DVB's multifunctional role as a coagent and emphasize the synergistic benefits of ionizing radiation, making VMQ‐DVB elastomers suitable for advanced damping applications.