Access to nonisocyanate poly(thio)urethanes: A comparative study

Abstract

This article describes the synthesis of new cyclic compounds able to react with amines to get nonisocyanate polyurethanes (NIPUs). The contribution of the most studied five‐membered cyclic carbonate was compared to five‐membered cyclic dithiocarbonate analogous and to a six‐membered cyclic carbonate. Difunctional reactive species were obtained by a simple substitution reaction or an efficient thiol–ene coupling reaction. The products, obtained with high yields, were characterized by 1H NMR, 13C NMR, and Fourier tansform infrared spectroscopy analysis. The dicyclocarbonates were then used to synthesize NIPUs by step growth polymerization with several diamines. These materials exhibited glass transition temperatures from 19 to −29 °C, molar mass from 1800 to 20,400 g mol−1, and a 20% mass loss temperature (Td = 20%) between 249 and 296 °C. Such materials are interesting candidates for coating applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3284–3296

How to explain low molar masses in PolyHydroxyUrethanes (PHUs)

“…This compound 19 was selected because it has no ester bonds, which could have introduced additional side-reactions [19,24]. The formation of amide groups can indeed be observed when reacting primary aliphatic amines, or even cycloaliphatic amines with compounds bearing ester groups such as vegetable oils for instance [35,36].…”

“…A non-isocyanate polyurethane was synthesized at 80°C using 1,10-decanediamine and the bis-5-membered cyclic carbonate 19 (same conditions as model reactions, Scheme 8) [24].…”

“…Among cyclic carbonates, 5-membered cyclic carbonates (5CC) react with primary amines mainly at high temperature, or they need the use of a catalyst at room temperature. However, the synthesis of 5CC is very easy and inexpensive since the typical process involves the reaction of an epoxide with carbon dioxide (under pressure) in the presence of a catalyst to yield the desired product with almost a quantitative conversion and using very mild conditions [21][22][23][24][25][26]. Therefore these 5-membered derivatives are the most widely studied for the reaction with amines to produce b-hydroxyurethanes.…”

Syntheses of epoxyurethane polymers from isocyanate free oligo-polyhydroxyurethane

“…To solve these problems, many studies in the literature have been conducted to design PHUs from more reactive cyclic-carbonates, bearing electro-withdrawing substituent [15,17,22,24,30,31,[34][35][36][37][38][39] or by using sixmembered, seven-membered or thio-cyclic carbonate [23,26,31,40,41]. But, the preparation of these compounds involves phosgene or its derivatives for six-membered carbonates or carbon disulfides for thiocarbonates, which remain harmful reactants [23,26,31,33,40,41].…”

“…However, this reaction has two major drawbacks: the low reactivity of carbonate/amine reaction at room temperature [26] when compared to iscocyanate/alcool and the low molar masses of PHUs obtained (Mn between 1.800 and 28.000 g mol À1 ) [15,22,[30][31][32][33]. To solve these problems, many studies in the literature have been conducted to design PHUs from more reactive cyclic-carbonates, bearing electro-withdrawing substituent [15,17,22,24,30,31,[34][35][36][37][38][39] or by using sixmembered, seven-membered or thio-cyclic carbonate [23,26,31,40,41].…”