Synthesis and characterization of N,N-(pyromellitoyl)-bis-L-phenylalanine diacid ester butynediol

N,N-(pyromellitoyl)-bis-L-phenylalanine diacid ester butynediol (PBDCB) from pyromellitic dianhydride (PMDA), butynediol (2-butyne-1,4-diol) and DL-phenylalanine (DLP) was synthesized. The PBDCB can be used as chain extender for thermoplastic polyurethane. The starting material of N,N-(pyromellitoyl)-bis-L-phenylalanine diacid (PBD) was synthesized through addition reaction between PMDA and DLP. Then, PBD was esterified using triethylamine as catalyst and attached antacids as well as dimethylacetamide (DMAc) as solvent. The obtained PBDCB was characterized using Fourier transformed infrared spectroscopy (FTIR), nuclear magnetic resonance (¹H NMR) spectroscopy, mass spectrometry (MS), thermal gravimetric (TG), and differential scanning calorimetry (DSC). The results showed that the PBDCB was highly thermal stable.