Preparation And Characterization Of Polybenzoxazine Spherical Resin

Three kinds of spherical polybenzoxazine, called P-P-B, G-A-B and P-A-B, were synthesized by changing amine and phenol resources. And three spherical polybenzoxazine resins, called S-P-P-B, S-G-A-B and S-P-A-B, were obtained by reverse-phase suspension solidification. Especially, the S-P-A-B resin was combined with a guanidine group after synthesized. What's more, the self-assembly mechanics and process in reverse-phase suspension solidification were deduced in detail. The spherical resins were identified by SEM (scanning electronic microscope), TGA (thermogravimetric analysis), DSC (differential scanning calorimetry) and IR. Finally, the adsorption property was studied base on the features of the three spherical resins.The study of reverse-phase suspension solidification of P-P-B indicated that the solidification medium, the volume ratio of precursor to medium, the solidification temperature and the agitation speed played important roles in synthesizing S-P-P-B resins. The appropriate solidification medium was silicone oil, and the volume ratio of precursor to medium was 5:50. When other conditions were fixed, the size of the resin became smaller with the increasing of stir speed. Compared with conventional solidification, the reverse-phase suspension technique reduced the polymerization time to 30-40min.The G-A-B precursor which had hydrophilic and hydrophobic moieties was distributed in silicone oil and formed micelle by agitating. However, this micelle had hydrophilic core and hydrophobic shell. When the system was heated at an appropriate temperature, the ring-open reaction of G-A-B precursor was carried out in hydrophilic core which was combined by intra-and/or intermolecular interactions of hydrogen bond, while the hydrophobic shell was not polymerized. And the self-assembly S-G-A-B resin was obtained. According to SEM photograph, the S-G-A-B resin was tight and had shape of completely and perfectly round. The high decomposition temperature showed in TGA figure indicated that the thermal stability of self-assembly resin was much better than the polybenzoxazine resin obtained by conventional solidification. And according to SEM photograph and TGA figure, the existence of self-assembly process was approved.The S-P-A-B-G was obtained after the S-P-A-B resin being combined with a guanidine group. And the IR spectrogram, TGA and DSC results approved the existence of guanidine group in S-P-A-B-G.The adsorption of the S-P-P-B resin on methylene blue and the adsorption of S-G-A-B resin on vitamin C were in line with Langmuir adsorption isotherm equation. The correlation coefficient had reached more than 0.9 which indicated that the two adsorption behaviors were monolayer adsorption. The saturated adsorptive capacity (As) were 0.137 mg·g^-1, 0.114mg·g^-1 respectively.