Materials, Methods & Technologies, Volume 13, 2019

Abstract: This paper presents studies on the development and characterization of nanocomposites based on natural rubber, plasticized starch, precipitated silica and layered clay such as organically modified montmorillonite (OMMT). Mixtures were made containing 0, 3 and 6 phr (parts per 100 parts rubber) OMMT, respectively. They were obtained by melt intercalation in a Brabender mixer at 12/80 rotations/min and 100-150ºC, for 10 minutes. Curing agents (sulfur and curing accelerators) were embedded on a laboratory roller at 90ºC, friction 1:1.1, processing time 5 minutes. Rubber specimens were obtained by compression, using a hydraulic press at 165ºC and a pressing force of 300 kN. Curing time, determined using the Monsanto rheometer, decreases with the increased amount of OMMT in the mixtures. At the same time, it was noticed that mixtures containing OMMT show improvement in physical-mechanical properties and resistance in various working environments specific to the food and pharmaceutical industry. Permanent compressive deformation 25%, 24hx70°C shows very good values for mixtures containing OMMT. The new types of nanocomposites may be used to obtain O-rings for the sugar industry or for other areas of application.