Preparation of Novel, Nanocomposite Stannoxane-Based Organic–Inorganic Epoxy Polymers containing Ionic bonds

Abstract

Polymer nanocomposites of epoxies with a novel filler, amino-functional butyltin oxide cage (stannoxane), were prepared and characterized. The nanofiller displays a promising antioxidizing effect, besides mechanical matrix reinforcement. The reinforcement can be assigned to physical interactions among the polymer bonded nanofiller. Moreover, the stannoxane cage undergoes a rearrangement to larger poly amino-functional nano-objects at higher temperatures, which highly reduces its extractability: it is practically not extractable from the nanocomposites in most cases. This, together with the fact that only a few weight percent are needed to achieve an optimal effect, makes it attractive as an antioxidative stabilizer. Epoxy–stannoxane nanocomposite synthesis, stannoxane reactivity and dispersion (morphology via TEM and SAXS), as well as the nanofiller effect on mechanical properties (DMTA) and on thermal stability are discussed. A brief comparison is drawn between the stannoxanes and the previously investigated POSS nanofiller.

Super-porous nanocomposite PNIPAm hydrogels reinforced with titania nanoparticles, displaying a very fast temperature response as well as pH-sensitivity

“…Nanometer-sized fillers are known to very efficiently reinforce polymeric matrices, due to the high specific surface of the former [44][45][46][47][48][49][50][51]52,53,26]. In their previous work, some of the authors of this paper studied PNIPAm hydrogels reinforced by siloxane-based inorganic nano-phases [54].…”

Reactivity of the tin homolog of POSS, butylstannoxane dodecamer, in oxygen-induced crosslinking reactions with an organic polymer matrix: Study of long-time behavior

“…The elastic matrix and the linearly bonding Sn2 cage were chosen for the study of the oxidative crosslinking because of the very strong anti-oxidizing effect found in this system [59] by the authors. Hybrid networks with the following weight loadings of Sn2 were prepared: 0% Sn2 (neat matrix) and 0.05e100 mol% Sn2 (^0.1e40 wt%, see Table 1).…”

“…the procedure published in Ref. [64], using the molten and supercooled epoxide DGEBA, the liquid Jeffamine D2000 and a 50 wt% stannoxane "Sn2" cage solution in toluene. (This solvent was removed just after gelation of the reaction mixture, it served to ensure good compatibility in the early stages of the reaction blending of the epoxide with Sn2).…”

“…A specific property is also the rearrangement into larger structures at elevated temperature [55,58] (Scheme 2b). A very attractive property of the Sn-POSS cage is its ability to undergo oxidative debutylation and crosslinking reactions (Scheme 2a) which can counteract the oxidative degradation of polymeric matrices [59].…”

“…Recently, the authors of this work prepared and investigated several Epoxy/Sn-POSS hybrids [58,59,64,65] (see example in Scheme 4), in which Sn-POSS displayed a distinct anti-oxidative effect, even at very low concentrations.…”