Titanosilsesquioxanes Embedded in Synthetic Clay as a Hybrid Material for Polymer Science

Abstract

Zwischen den Schichten: Ein neuartiges Hybridmaterial (siehe Bild) wurde durch die Interkalation eines difunktionellen Titanosilsesquioxans in synthetisches Natriumsaponit erhalten. Ein Nanokomposit aus einer Polystyrolmatrix und dem Hybrid als Additiv weist verbesserte thermooxidative Eigenschaften auf.

Organic–Inorganic Hybrid Saponites Obtained by Intercalation of Titano‐Silsesquioxane

“…TGA results suggest that the intercalation of Ti‐NH 3 POSS in both saponite materials resulted in a significant modification of the thermal degradation pathways of POSS molecules. Interestingly, both hybrid samples showed thermal decomposition of the organic chains of Ti‐NH 3 POSS at higher temperature (above 400 °C) than pure Ti‐NH 2 POSS (around 300 °C),20 thus indicating that when intercalated within the saponite interlayer space, the degradation was significantly delayed with respect to pure Ti‐NH 2 POSS. This behavior can be associated to the fact that the clay structure plays an active role in stabilizing and protecting Ti‐NH 3 POSS molecules by increasing their thermal stability.…”

“…As recently shown, after the acid activation, saponite samples contain two families of Brønsted acid sites with medium and high acidity 25. As far as the Ti‐NH 3 POSS/Na‐SAP (Ti‐NHM‐1)20 hybrid material is concerned, the exchange procedure resulted in a drastic decrease of sodium content (from 0.45 to 0.04 mmol g −1 ) suggesting that more than 90 % of Na + ions located in the interlamellar space of the saponite structure were replaced by protonated Ti‐NH 3 POSS ions. Materials with different Ti content were obtained depending on the type of saponite used for the exchange procedure (i.e., Na‐SAP or H‐SAP).…”

“…310 °C, Figure 5 B, curve b). In addition, the thermal profile of Ti‐NHM‐1 (Figure 5 A, curve b) showed a weight loss of about 10 wt % between 500 and 750 °C, which can be due to the formation of charring products during the degradation of the Ti‐NH 3 POSS organic chains 20. Ti‐NHM‐2 did not show a significant weight loss in the range from 500 to 750 °C (Figure 5 A I 5, curve b).…”

“…The catalytic dehydrogenation performances of Ti‐NH 3 POSS embedded in sodium saponite (Ti‐NHM‐1) should be exploited for applications in polymer science, for example, in the preparation of polymer composites with enhanced thermal properties, which have already been reported in the literature in the case of composite material based on polystyrene 20. In this case, the catalytic activity of Ti centers in combination with the physical barrier effects offered by the clay should be relevant for the formation of charring products, which have flame‐retardant effects, during combustion.…”

“…Recently, a novel hybrid material (named Ti‐NHM‐1) with improved thermal properties was prepared in our laboratories by the insertion of a novel functionalized M‐POSS (Ti‐NH 2 POSS)19 in a synthetic Na saponite. Its application as nanofiller for polystyrene matrix was suggested 20. Ti‐NH 2 POSS is a versatile silsesquioxane19 with a molecular structure containing two functionalities: a titanium metal center, which may display catalytic properties when dispersed or anchored on different silica materials21 and/or polymeric supports,22, 23 and a functional amino group suitable for the intercalation in clay‐like solids (Figure 1).…”