Optimization of curing agent amount and radiation absorbed dose for ethylene-propylene-diene rubber/natural rubber blends

Abstract

The optimal design of curing agent amount and radiation absorbed dose in application of radiation crosslinking technology for ethylene-propylene-diene rubber / natural rubber blends was discussed. By combining the amount of curing agent and radiation absorbed dose to form different crosslinking schemes, regression equations between the curing agent amount and radiation absorbed dose and modulus at 100%, tensile strength and elongation at break were obtained by regression analysis of test results of the blend properties under different crosslinking schemes. According to the regression equations, 2-dimensional contour diagram and 3-dimensional surface diagram were displayed through visual simulation, and the results of regression ana-lysis were verified by optimizing crosslinking combination schemes. The results showed that the increase of increment coefficient of curing agent and radiation absorbed dose could increase elastic modulus of the blend, leading to an increase in modulus at 100% and a decrease in elongation at break. With the increase of curing agent amount and radiation absorbed dose, tensile strength of the blend first increased and then gradually decreased. The scheme of high curing agent amount with low radiation absorbed dose was suitable for preparing rubber materials with high requirements on modulus and strength, while the low curing agent amount with high radiation absorbed dose scheme was suitable for materials with high requirements on elongation at break and aging resistance.

Keywords

• natural rubber
• ethylene-propylene-diene rubber
• blend; curing agent
• radiation absorbed dose
• tensile property
• regression analysis