Designing heterogeneity into bimodal elastomeric PDMS networks

Bimodal poly(dimethylsiloxane) (PDMS) networks prepared using a dual-step p rocess have been studied. It is shown that these networks exhibit a signifi cant increase in equilibrium modulus. This reinforcement can be obtained by adjusting a process parameter, the "heterogeneity time", during network pr eparation. The increase in modulus is attributed to the clustering of the s hort chains that is effected through proper use of heterogeneity time.