Thermal Protection of Polyamide 6/Acrylonitrile–butadiene Rubber Thermoplastic-Vulcanizates: Influence of Type and Content on Blend Properties

Abstract

Polyamide 6 (PA6)/NBR blends are interesting because of their supposed properties at elevated temperatures. The blend, however, has a critical problem in terms of processing stability, as a result of the thermal degradation of the NBR phase. We evaluate a system of dissimilar addition of antioxidant in each phase (a combination of Irganox®/Irgafos® for the PA phase, and Naugard 445® for the NBR phase) and study the influence of these antioxidants on the properties of the blend. The evaluation was performed through tensile strength, differential scanning calorimetry (DSC), thermogravimetric analysis, and X-ray diffraction analysis. The influence of the antioxidant system on the crystallization process of the PA phase was evaluated through isothermal DSC analysis. Results showed the best combination of antioxidant addition in master batches and during processing.

Thermal decomposition kinetics of dynamically vulcanized polyamide 6–acrylonitrile butadiene rubber–halloysite nanotube nanocomposites

“…Before the thermal degradation of TPE nanocomposites is studied, there is a need to assess the thermal degradation of the nanoclay and blends prepared at different compositions to postulate the contribution of ingredients to the thermal stability enhancement. It was apparent from previous studies that the removal of water molecules present in PA6 from an PA6–NBR blend was probable at low temperatures, whereas the butadiene and acrylonitrile portions of NBR could be thermally degraded at higher temperatures together with the amide linkage of PA6, which might need more energy . The considerable mass loss at elevated temperatures could also be ascribed to chain scission, as schematically illustrated in Figure .…”

“…It was apparent from previous studies that the removal of water molecules present in PA6 from an PA6-NBR blend was probable at low temperatures, whereas the butadiene and acrylonitrile portions of NBR could be thermally degraded at higher temperatures together with the amide linkage of PA6, which might need more energy. 57 The considerable mass loss at elevated temperatures could also be ascribed to chain scission, 58 as schematically illustrated in Figure 2.…”