Silica Reinforced Organic-Inorganic Hybrid Polyurethane Nanocomposites From Sustainable Resource

Polyol/nanosilica organic-inorganic hybrids (Si/Lpol) were prepared through facile sol-gel chemistry. Tetraethoxyorthosilane (TEOS) and linseed polyol (Lpol) obtained by hydroxylation of linseed oil were used as inorganic and organic precursors, respectively. Si/Lpol was further treated with toluene-2,4-diisocyanate (TDI) to obtain silica embedded polyurethane (Si/LPU). The structure of the organic-inorganic hybrid was confirmed by FTIR, H-1 NMR, and C-13 NMR spectral analysis. The polyol/nanosilica network shows strong interaction with the remnant polyol backbone through hydrogen bonding, which also has bearing on T-g of polymers. Morphological studies of Si/LPU show the formation of uniform, spherical silica nanoparticles of 2-30 nm size embedded in the polymer matrix. Si/LPU was further reinforced with 2 and 5 wt.-% fumed silica (FS-Si/LPUs); their morphology revealed a carpet layer formation on top of Si/LPU. Thermogravimetric analysis showed improved thermal stability of Si/LPU and FS-Si/LPUs. The polymers exhibit mild to moderate antibacterial behavior against E. coli and S. aureus, respectively, and will pave way in plethora of biological and chemical applications as coating materials.