Predicting the properties of carbon black/silica-filled natural rubber-based compound by specifying the protein and lipid contents of natural rubber, before compounding

Nowadays, the protein and lipid contents of natural rubber are not included in most of the rubber’s data sheet. This study investigates the effects of the mentioned parameters on the cure and some physico-mechanical features of natural rubber based compounds, filled with carbon black/silica as a dual filler. Kjeldahl and extraction methods are applied to measure the protein and lipid contents of different types of natural rubber, respectively. The first and second-order fitting models show the correlations between the protein, lipid, and protein+lipid contents with cure and some physicomechanical characteristics. The introduced models are used to estimate the features in the case study. Results are presented that, by applying the correlations between lipid content and torque difference, cure rate index, scorch time, optimum cure time, and modulus 100%, these properties can be estimated by less than 10% error. Using the correlations between the protein content with compression set and resilience make it possible to predict these properties with less than 10% and 15% errors respectively. The outcomes present the importance of clarity of the protein and lipid contents of natural rubber for preparing well-designed, high-performance products before compounding.