Titanium tetrapropoxide

Long-chain esters of pentaerythritol have been prepared by a variety of methods. The tetranonanoate is made by treatment of methyl nonanoate [7289-51-2] and pentaerythritol at elevated temperatures using sodium phenoxide alone, or titanium tetrapropoxide in xylene (12). PhenoHc esters having good antioxidant activity have been synthesized by reaction of phenols or long-chain aUphatic acids and pentaerythritol or trimethyl olpropane (13). 

In one example, the colloidal structure, is made by sedimentation of polystyrene beads, giving voids in the range 120-1000 mn, and the voids are filled with TiO generated from titanium tetrapropoxide. The polystyrene bead lattice is then removed by calcining to give an iridescent material, but not with a full photonic band gap. In this case one of the controlling factors is the refractive index of the matrix, which needs to be greater than 2.8. 

In addition, REX processing was used to chemically modify PLA via an alcoholysis mechanism for blown film applications. In this case, intensive alcoholysis reactions from a diol solution or from functionalized alcohol promoted by titanium tetrapropoxide were carried out to tune the PLA chain length and rheology. It was found that under certain alcoholysis conditions, the resulting PLA blends were suitable for melt-blown non-woven processing. 

Que et al. have reported the fabrication of optical channel wavegides and gratings made from composites of titania and organically modified silane (Que et al., 2002). The composite is prepared using 3-glycidoxypropyltrimethoxysilane and titanium tetrapropoxide stabilized with acetylacetone as precursors. Dense and porosity-free waveguide film is obtained... 

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