Thermoset rubber/layered silicate nanocomposites. Status and future trends

This paper surveys the recent achievements with thermoset rubber/layered silicate nanocorr.posites considering their production methods, cure characteristics, structure and basic properties (mechanical, thermal and barrier). It was shown that the properties of the "nanoreinforced" rubbers strongly depend on the dispersion state of the silicate. The latter can be influenced by various methods related to the production route (latex, solution or melt compounding), silicate type (natural and artificial origin mostly affecting the aspect ratio), surface modification of the silicate (chemical buildup Of the surfactant used for "organophilization"), recipe (curatives, activators, compatibilizers, etc.) and compounding parameters (temperature, time, shear rate, etc.). A peculiar skeleton-type reinforcing structure can be produced by latex compounding. Solution and melt intercalation techniques usually result in nanocomposites containing silicate layers in both intercalated and exfoliated forms. To detect the related structure the combined use of transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques is inevitable. Confinement and deintercalation of the organophilic layered silicates occurring during compounding can be circumvented by the proper selection of the surfactants. Based on the present praxis some tendencies for future R&D activities with rubber nanocomposites were deduced and a strong impetus was forecasted to them owing to the fast development with thermoplastic /layered silicate systems. (C) 2004 society of Plastics Engineers.