The Influence of Cure System and Crosslink Density on Various Properties

By selecting the dosage of components within a sulfur cure system, one can influence both the crosslink density and the crosslink type (length). When a high sulfur dosage is used to achieve a conventional vulcanization (CV) system, even the cure temperature significantly impacts these two parameters. To achieve optimal properties, one of the most critical factors is determining the cure system and optimizing the cure temperature. The table below presents the influence of the two parameters—crosslink density and crosslink length—on various properties.

Property CLD incresing CL length incresing
Tensile Strength  initially increases and then decreases. Increases
Elongation @ Break Decreases -
Flex Life Decreases Increases
Modulus Increases -
Resilience Increases Decreases
Set Decreases Increases
Abrasion Resistance Increases Increases
Rolling Resistance Decreases -
Hystersis Decreases Increases
Dimensional Stability - Decreases
Oxidation Stability - Decreases
Tear Strength  initially increases and then decreases. Increases