This folder contains post-processed data extracted from Fig. 4 found in Mullins & Tobin (1957). The data has been reproduced with permission from "Theoretical model for the elastic behavior of filler-reinforced vulcanized rubbers". Copyright © 2026, Rubber Division, American Chemical Society, Inc. 

The original publication presents its data in unconstrained uniaxial extension as nominal stress over engineering strain. We have converted the engineering strains to stretches. The original units of stress are given as "kilogramm per centimeter squared" and the load is force-controlled by application of weights. We have converted the units to "pascal", i.e., "kilogramm per second squared per meter", by multiplying the original stress values by an gravitational acceleration of 9.81 meters per second squared. 

All files are given as comma-separated values in two columns: (i) the stretch and (ii) the nominal stress. This is also made clear by the header in each file. There are six csv-files in total:
- primary_loading.csv
- unloading_1.csv
- unloading_2.csv
- unloading_3.csv
- unloading_4.csv
- unloading_5.csv
The numbers indicate the corresponding cycle.

Reference:
L. Mullins and N. R. Tobin. Theoretical model for the elastic behavior of filler-reinforced vulcanized rubbers. Rubber Chem. Technol., 30(2):555–571, 1957. doi: 10.5254/1.3542705.