ABSTRACT
The authors cited in the introduction have used and continue to use a limited number of products. The physical properties of casting agents and their chemical properties determine the field of application of the technique and the quality of the casts. The room temperature vulcanizable (RTV) range of Rhone-Poulenc, France, is composed of liquid polysiloxanes produced for various industrial uses. The product RTV 141 consists of two components, A and B. The first is a polysiloxane with long chains, bearing vinyl and methyl radicals, supplemented by a catalyst. The second is a polysiloxane with short chains and H radicals. The hardened elastomer is transparent with a refractive index of 1.40. The elastic limit of elastomer filaments constituted by the vascular casts seems to vary inversely with their diameter, as if the passage through the network of the finest pores has the effect of increasing the number of covalent bonds between the chains and, thus, the elasticity of the hardened elastomer.
