Synthesis and characterization of N‐phenylated aromatic polyureas from dianilino compounds and aromatic diisocyanates

Abstract

SynopsisN-phenylated aromatic polyureas were synthesized by the polyaddition of dianilino compounds to aromatic diisocyanates in sym-tetrachloroethane at around 100°C. Factors that influence the reaction, such as monomer concentration, reaction solvent, catalyst, temperature, and time, were studied to optimize the conditions for the preparation of high molecular weight polymers. Compared with the analogous unsubstituted aromatic polyureas, the N-phenylated polyureas were almost amorphous and soluble in a variety of solvents and had low glass transition temperatures. Some of the polymers could be cast into transparent flexible films from chloroform solutions.

Synthesis and characterization of soluble aromatic polyurea‐amides from new N,N′‐‐dimethyl‐N,N′‐bis(aminophenyl)ureas and aromatic dicarboxylic acid chlorides

“…In our previous article, we have reported the synthesis of N-phenylated aromatic polyureas from dianilino compounds and aromatic diisocyanates, which exhibited good solubility in organic solvents such as tetrahydrofuran. 2 We have also demonstrated the synthesis of N-phenylated polyureas from N,N'-diphenyl substituted polyurea was stable up to a temperature as high as 45OoC, despite the low inherent vis~osity.~ On the other hand, the fully Nmethylated or N-phenylated polyamides have good thermal stability and good solubility at the same time. However, their glass transition temperatures (T,) were too low for high-performance materials because of the absence of hydrogen From these results, we designed new polyurea-amides for the present study having both good solubility based on N,N'-dimethylated urea units and good thermal properties based on amide units starting from new diamines.…”

Design, Synthesis, and Photodegradation of Silicon‐Containing Polyureas

“…(Bromomethyl)diphenylmethylsilane (2 c), (bromomethyl)triphenylsilane (2 d), dianilino-p-xylene (15), 2,2-dimethyl-N,N'-diphenyl malonamide (13), and N-(trimethylsilylmethyl) cyclohexylamine were prepared according to literature methods. [23][24][25][26][27] The experimental details for compounds 6, 11, and 19 will be reported elsewhere. The spectroscopic data and melting points of silicon-containing products 3 a-d, [28,29] 4 a-d, and 8 a-c are listed in Table 3.…”

Isocyanate‐ and Solvent‐Free Route to Thermoplastic Poly(amide‐urea) Derived from Renewable Resources

“…It is well recognized that hydrogen bonding between urea groups in the polymer back bone accounts for high polyurea melting and glass temperatures together with high melt and solution viscosities. Reducing intermolecular hydrogen bonding by varying the N ‐substitution pattern of the urea groups lowers polyurea phase transition temperatures but frequently adversely affect mechanical properties . Among the family of N ‐substituted polyurea, bulky N ‐substituents were reported to enable self‐healing .…”