SOME ATTEMPTS TO FORCE POLY(DIMETHYLSILOXANE) CHAINS THROUGH ZEOLITE CAVITIES TO IMPROVE ELASTOMER REINFORCEMENT

The reinforcing effects of zeolites in poly(dimethylsiloxane) (PDMS) elastomers were characterized using two preparalive approaches. In the first, end-functionalized polymer chains were blended into the zeolite, and were then endlinked into the required network structure. The second approach represented an attempt to force some chains through the cavities, by blending the monomer itself into the zeolite and then polymerizing it to obtain the PDMS elastomer. The two types of zeolitc-filled PDMS were characterized using stress-strain measurements in elongation, equilibrium swelling, and small-angle X-ray scattering. The second synthetic approach did seem to give improvements in mechanical properties, particularly when the average cavity size of the zeolite particles was relatively large. Ascribing the observed improvements in rcinforcement at least partly to the threading of some PDMS chains through the zeolites was supported by the results obtained in the swelling and scattering experiments.