Synthesis And Epoxidation Of Hyperbranched Polyesters

This work is related with the synthesis and epoxidation of hyperbranched polyesters from the ring opening polymerization of multifunctional acid anhydride and epoxy compounds. Hyperbranched polyesters were synthesized in one pot from the polymerization of trimellitic anhydride(TMA) with epichlorohydrin(ECH), and TMA with propylene oxide (PO), at 70 ℃ and 100℃, respectively. Elemental reactions of the ring opening polymerization indicated that the two ring opening reactions of benzoic acid with epichlorohydrin (1) and Phthalic anhydride with propyl alcohol proceeded easily under the mild condition of polymerization, and the two - COOH groups on the monoester of trimellitic acid showed the same reactivity toward epoxy ECH. The direct reaction between carbonyl acid and hydroxyl was not detected at 70℃, but at 100℃ it was performedwith about 5.2% yield after 12h reaction. From the reaction products of benzoic acid and ECH, m/z 215 and 179, as well as 216 and ISOwere found on the mass spectra of HPLC-MSS. There were absorption peaks at 1662 cm-1 on the FTIR spectra, and resonance absorption at 6 5. 6-6. 2 ppm on the 1H-NMR spectra of the hyperbranched polyesters. These results indicated that there existed vinyl structures in the hyperbranched polyesters from the elimination side reaction during the polymerization. Factors including polymerization temperature, addition manners, have effects on the synthesis and molecular weight of hyperbranched polyester. The functional groups on the chain ends of polyesters can be adjusted by the ratio of TMA to epoxy. Thermal properties of the polyesters were greatly related with the composition of these functional groups. The a constant in the Mark-Houwink equation was 0. 29, as calculated from combined GPC and viscosity measurements, indicating the polyester chains were highly branched. The actual molecular weight of the polyester was not successively measured by MALDI-TOF MS, and was affected by eluent if measured using GPC.Hyperbranched polyesters from TMA and ECH with chain end - OH groups was deoxidized. The amount of base and temperature affected epoxy value of the polymers. The deoxidized hyperbranched polyesters were thermally cured with Phthalic anhydride and studied with DSC. Activate energy were calculated to be 64.35KJ/mol,91.12KJ/mol, and the corresponding frequency parameter InA are 21.8 and 26.8.