Polymers of carbonic acid, 8. Linear polybiurets

• Published in: Die Makromolekulare Chemie
• Main Authors: Kricheldorf, Hans R., Meier‐Haack, Jochen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1992
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/macp.1992.021931012; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fmacp.1992.021931012; https://onlinelibrary.wiley.com/doi/pdf/10.1002/macp.1992.021931012

Abstract Linear polybiurets can be synthesized by polycondensation of chloroformyl isocyanate and N , N ′‐bis(trimethylsilyl)‐α,ω‐diaminoalkanes or silylated aromatic diamines. The polybiurets were characterized by elemental analyses, inherent viscosity measurements, IR spectroscopy, 1 H, 13 C, 15 N NMR spectroscopy in solution, differential scanning calorimetry (DSC) measurements, wide‐angle X‐ray scattering (WAXS) and thermogravimetric analyses. All polybiurets are semicrystalline materials with a low rate of crystallization and unexpectedly low melting points. 13 C and 15 N NMR cross‐polarization/magic angle spinning (CP/MAS) spectra of the solid polybiurets indicate different conformations for the amorphous and crystalline phase. All polybiurets gradually decompose upon heating above 200°C. Synthetic methods and properties of linear biurets were also checked by synthesis and characterization of N , N ′‐dioctylbiuret.