Percolation-type growth of branched polymers near gelation threshold

We present experimental results to illustrate the percolation model, and use this model to describe the structure and mass distribution of clusters, the increase of the connectivity as the percolation threshold is approached, as well as transport properties of electrical percolating networks. We discuss results obtained from neutron and light scattering and from mechanical measurements. A good agreement between theory and experiment allows the growth of polymer clusters during the gelation process to be understood. Results obtained from mechanical measurements are quite similar to the behaviour of electrical properties of percolating networks, but are not yet understood completely.