Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5181154 | Polymer | 2014 | 18 Pages |
â¢n-butylstannoxane dodecamer cages were incorporated into an epoxy matrixâ¢The cages were incorporated as linear unitsâ¢The cages display a strong anti-oxidative effect via crosslinking reactionsâ¢The cages can additionally reinforce the matrix via cage oligomerizationâ¢The ionic-bonded cages display an unusual mobility in the matrix at 180 °C
A novel tin-based POSS analogue, butylstannoxane dodecamer, was incorporated as chemically active nanofiller in epoxy resins and achieved a considerable anti-oxidative activity already near 0.05Â wt% and very high activity near 1Â wt%. The amino-functional nanofiller, which bonds as a linear segment, displayed a high reactivity towards the resin components during cure and was very poorly extractable. Interestingly, at elevated temperatures, the stannoxane nanofiller, whose functional substituents are attached by ionic bonds, displays a considerable short-range mobility in the matrix, and in course of a nano-phase-separation process, rearranges and polymerizes to needle-like nano-domains. This effect leads to additional crosslinking in the nanocomposite. This “solid-phase nano-precipitation” does not occur under oxidative conditions, where the nanofiller preferentially undergoes crosslinking with matrix chains and is thereby immobilized. Nanocomposite synthesis, characterization and the concentration dependence of the nanofiller effect are presented.
Graphical abstractDownload high-res image (200KB)Download full-size image