Modification of the Filler based on Kaolin and its Use in the Polymer Composites

Abstract

Light mineral fillers are the natural inorganic materials of various compositions that have been used in a practical way since the beginning of the rubber industrial processing. Depending on the application, the natural kaolin is often modified by physical processes or by chemical processes (pillaring, adsorption, intercalation, functionalization, acid activation, etc.). It is important to modify kaolin due to improvement of its properties in order to adsorb the inorganic as well as organic molecules. In the introduced study, kaolin from Kaznějov deposit was modified by potassium acetate or dimethylsulphoxide and subsequently functionalized by accelerator dibenzothiazyldisulphide and its last modification was performed by silane treatment. Different techniques, such as the thermal (DTA) and spectral (FTIR) analysis were used to characterize modified kaolin samples. The main aim of the article is to observe the influence of modified kaolin forms on the physico-mechanical properties and structural changes of rubber mixtures. Combined with the carbon black, the given modified kaolin was mixed into a rubber blend in a particular ratio, which was5, 10, 24 phr. The effect of the modified kaolinite on the cure characteristics (minimum torque – ML, maximum torque – MH, optimal cure time – t90, scorch time ts2) and mechanical properties (tensile strength at break – TSb, elongation at break – Eb and hardness)in sulphur-cured rubber composites was investigated. In images from a scanning electron microscope (SEM), we observed the incorporation of modified forms of kaolin into the matrix of the rubber mixture.

Combination effect of ADP‐intercalated kaolinite and ammonium polyphosphate on simultaneously enhancing the flame retardancy and smoke suppression of epoxy resins

“…Figure 2B presents the pyrolysis curves of Kaol and K‐ADP. The TG curve of Kaol displays a major mass loss during 500–650°C with a peak at 597°C in the DTG curve, attributing to the dehydroxylation process 28 . As for K‐ADP, the release of deamination and water of ADP results two decomposition stages before 300°C 29 .…”

“…The TG curve of Kaol displays a major mass loss during 500-650 C with a peak at 597 C in the DTG curve, attributing to the dehydroxylation process. 28 As for K-ADP, the release of deamination and water of ADP results two decomposition stages before 300 C. 29 Meanwhile, K-ADP owes a lower dehydroxylation temperature of 570 C compared to that of Kaol, indicating that the increased interlayer spacing enlarges the contact area between the hydroxyl group and the external heat. 25 The SEM images of Kaol and K-ADP are shown in Figure 3.…”