Thermoplastic polyurethane urea modified with ethylene glycol ricinoleate

Abstract

This work synthesized a polyurethane urea copolymer (PUU) and polyurethane urea modified with 5% molar of ethylene glycol ricinoleate (PUU5R). Ethylene glycol ricinoleate (REG) was synthesized, characterized, and introduced in the first stage of the PUU reaction. The characterization of the modified PUU5R product was carried out employing Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR), and mechanical tests in traction mode. Through FTIR, it was possible to identify characteristic modes for the PUU and PUU5R. The most relevant modifications of the modification on the -CO vibrational mode located at 1630 and 3440 cm–1 corresponding to the vibrational mode of the -NH group free of bonding hydrogen that indicates an increase in the hydrogen bonds of the urea group and a reduction in the urethane group of the modified product, and by NMR the -CH proton of the ricinoleate unsaturation in 5.4 ppm of the PUU5R was detected verifying its incorporation in the PUU. Through DSC thermal tests, a reduction in cold crystallization and an increase in the Tg of the product were established due to the structural change caused by the pendant group of ricinoleate. However, TGA thermograms do not show relevant changes in its thermal stability. Finally, the mechanical tensile tests for the modified PUU5R product show an increase in modulus and a reduction in elongation.