Synthesis and characterization of dimethacrylate monomer with high molecular weight for root canal filling materials.

A new dimethacrylate monomer 9,9'-bis[4-(2'-hydroxy-3'-methacryloyloxy-propoxy)phenyl] fluorene (3) with a molecular weight of 634 was synthesized in 51.4% yield by addition of a glycidyl ether group to 9,9'-bis(4-hydroxyphenyl) fluorene (1) by the reaction of compound 1 with epichlorohydrin, and then introducing the methacrylate moiety by the reaction of the epoxy group with methacrylic acid. The structure of monomer 3 was confirmed by FT-IR, (1)H-NMR, mass spectra and elemental analysis.

[Syntheses and spectral characterization of low-molecular-weight chitosan-Ce(III) complexes].

The low-molecular-weight chitosan-Ce(III) complexes were synthesized at pH value 1-2 and characterized by UV spectrum, fluorescence spectrum, FTIR spectrum and 1H NMR spectrum. Its coordination mechanism was also investigated. The results showed that Ce(III) was coordinated with -OH group instead of -NH2 group of low-molecular-weight chitosan.