Direct Synthesis of Polyurea Thermoplastics from CO₂ and Diamines

Abstract

The transformation of CO2 into polymeric materials is an important and hot research topic from the viewpoint of renewable resources and environmental effects. Herein, a series of polyureas have been synthesized by polycondensation from CO2 with diamines of 1,12-diaminododecane (DAD) and/or 4,7,10-trioxa-1,13-tridecanediamine (TTD). The properties of polyureas synthesized were characterized by FTIR, 1H NMR, 13C NMR, XRD, DSC, TGA, and DMA. The polyureas synthesized from CO2 with a mixture of diamines presented high performances compared to those of polyureas synthesized from CO2 with a single diamine. The thermal and mechanical properties were improved largely by the variation in the crystallization and the chain flexibility depending on the changes in the density and/or intensity of hydrogen bonds. With increasing amounts of TTD from 0 to 100% in weight, the melting (T m), crystallization (T c), and glass transition (T g) temperatures decreased from 207 to 116 °C, from 181 to 54 °C, and from 66 to −34 °C, respectively. When the TTD content was increased from 0 to 50 wt %, the Young’s modulus decreased from 1170 to 406 MPa, and the tensile strength decreased from 53.3 to 42.9 MPa. However, the elongation at break increased from 13 to 330%. Furthermore, the chain length of aliphatic diamines and polyetheramines had a significant effect on the mechanical properties. The initial decomposition temperature (T d,5%) is >295 °C, about 110 °C higher than the T m (116–207 °C), which is advantageous for the postprocessing. The mechanical properties of the polyureas synthesized herein are superior to those of polycarbonate and polyamide 6. Thus, polyureas synthesized from the renewable and cheap resources, CO2 and diamines, will find wide potential applications in the field of polymeric materials.

A self-healing and recyclable polyurethane-urea Diels–Alder adduct synthesized from carbon dioxide and furfuryl amine

“…(Scheme S1 †). 36 The FTIR spectrum of PUa was similar to that of OUa; the absorption bands of the CvO stretching vibration at 1610 cm −1 and the N-H bending vibration at 1587 cm −1 were ascribed to the strong and ordered hydrogen bonded urea groups of PUa (Fig. S3 †).…”

“…PUa could not dissolve in DMF. 36 Therefore, OUa was used to react with BCCFA to synthesize PUUa. The reaction was detected by FTIR (Fig.…”

“…S4 †). 25,36 When TTD was reacted with BCCFA, the viscous liquid product obtained was further reacted with BIM and the TTD-DA so produced was a fragile gel, as a result, its mechanical properties cannot be measured, in which short TTD segments led to a very high crosslinking density of the DA adduct. To get a tough and strong material, we prepared PUUa.…”

“…23 CO 2 is reacted with appropriate reagents and catalysts to produce polyureas. [24][25][26][27][28][29][30][31][32][33][34][35][36] CO 2 -derived monomers such as cyclic carbonate, [37][38][39][40] carbamate, 41,42 and urea [43][44][45] are used to synthesize polyurethanes and polyureas. To date, a few types of self-healing and recyclable CO 2 -based polymeric materials have been reported.…”

Direct synthesis of polyureas from the dehydrogenative coupling of diamines and methanol

“…The first one is based on the synthesis of polyureas from the polycondensation of diamines with CO 2 . [2][3][4][5][6][7] Although the use of CO 2 for the synthesis of polyureas is attractive, the use of harsh reaction conditions such as reaction temperature of 170-180 1C, and CO 2 pressure of 40-110 bars, in order to overcome the high thermodynamic barriers, present a bottleneck to utilize this methodology on an industrial level. Another approach is based on the polycondensation of diamines with CO 2 derivatives -organic carbamates, [8][9][10][11][12] organic carbonates [13][14][15] and urea (NH 2 CONH 2 ).…”