Finally, we set out to compare the mechanical properties of our BSE-based HDPE materials to commercial HDPE. We note that commercial HDPE typically has a much larger molar mass (e.g., 100-300 kDa) than our ~40 kDa PE mimics, and indeed, tensile tests of these samples revealed much lower Young's moduli (~5 MPa) and strain-at-break values (~125 %) compared to HDPE (Figures ). As noted above, however, by tuning the ROMP reaction conditions, a high molecular weight sample, i PrSi8-co-PE-50-HMW, with a number-average molar mass of 154 kDa (theoretical Mn ~160 kDa) (Table ) could be prepared. This polymer was subjected to the same acid-mediated Si-O bond cleavage and subsequent step-growth repolymerization conditions as described above to generate a recycled sample of nearly equivalent molar mass (Figure ). The original and recycled materials were then compared to commercial HDPE via shear rheology and tensile tests.