Synthesis and Characterization of Poly (2-Butyne-1,4-Diol-co-Malic Acid) as an Inert Binder and Crosslinking with Glycidyl Azide Polymer

Unsaturated polyesters have several applications in organic chemistry such as click reaction, radical reaction, etc. In this research, in the first step, a new and inert type of unsaturated binder containing internal alkyne groups was synthesized. For this purpose, condensation polymerization of 2-butyne-1,‌4-diol, and DL-malic acid was performed at 130 °‌C without solvent. Thermal properties were studied by DSC and TGA analyses. All synthesized structures were confirmed by 1H NMR, 13C NMR, FT-IR, and GPC analyses. The synthesized poly (2-butyne-1,4-diol-co-malic acid) can be used as a binder and contains internal alkyne groups with a molecular weight is 1818 g.mol-1 and its polydispersity index of 1.75. According to the DSC study, the glass transition temperature of poly (2-butyne-1,4-diol-co-malic acid) was -38 °C, and its degradation temperature was 299 °C. Then, crosslinking and curing of poly (2-butyne-1,4-diol-co-malic acid) with glycidyl azide polymer was performed at 60 °C for 72 hours, and the tensile strength was obtained 5.63 MPa.