Well‐defined Biobased Segmented Polyureas Synthesis via a TBD‐catalyzed Isocyanate‐free Route

Abstract

Via an isocyanate-free route, a series of segmented polyureas (PUs) were synthesized from (potentially) renewable resources. To the best of our knowledge, the present work shows for the first time that the organic superbase guanidine 1,5,7-triazabicyclododecene (TBD) which was originally developed as a catalyst for the ring-opening polymerization of lactones, lactides or cyclic carbonates, is also a promising catalyst for the transurethanization between dicarbamates and diamino-terminated poly(propylene glycol) (PPGda) providing PUs via an isocyanate-free strategy. The renewable segmented PUs contain monodisperse hard segments (HSs). This well-defined structure was verified by the DMTA plots of the PUs, showing a sharp glass transition, a sharp flow transition and a flat rubbery plateau. The flow and maximum use temperature (Tfl ) of the PUs increases with the increasing number of urea groups in the corresponding dicarbamates. In addition, at constant HS length, the length of the soft-segment (SS) can be changed to adjust the properties of the PU materials, enabling their application as adhesives, soft elastomers, or rigid plastics.

Synthesis and properties of allyl terminated renewable non-isocyanate polyurethanes (NIPUs) and polyureas (NIPUreas) and study of their photo-crosslinking

“…In this respect, the transurethanization approach implying the reaction of a dicarbamate with a diamine can also be considered as a solution to prepare a broad range of polyurea materials. Indeed, Tang et al have recently used this approach to prepare polyurea materials exhibiting thermoplastic elastomer behavior [25].…”

Synthesis and evaluation of alkoxylated-ether diols of hydroquinone with different chain-lengths as extenders in segmented polyurethanes

“…[9,[19][20][21][22][23] Nevertheless, to our knowledge, all the methods reported so far have their drawbacks. Harthcock [20] and his co-workers had to use a cumbersome gel-permeation chromatogram process to isolate individual MDI-butanediol urethane extenders of uniform chain length from random product mixtures to demonstrate their effects.…”

“…The phenomenon of polar interactions helps induce their morphological development, which is consistent with Tang's conclusion in previous literature. [19] Moreover, through comparison of melting points and ΔH m values between PU3 (122°C; 16.7 J/ g) and PU4 (132°C; 25.0 J/g), the data clearly showed that longer and more precise extenders form tighter interactions between the PU hard segment chains.…”

“…[10][11][12][13][14] TPUs with a narrow dispersity in molecular weight generally show a higher and preferred elastic modulus, a less temperature-dependent modulus between the T g of the soft segment and the T m of the hard segments. [15][16][17][18][19] Electronic supplementary material The online version of this article (doi:10.1007/s10965-015-0812-5) contains supplementary material, which is available to authorized users.…”

Phosphorus-containing polymers from THPS.I. Design, synthesis, and characterization of novel monomer and polyureas

“…[37] Furthermore, many efforts have been made to synthesize directly polyurethanes and polyureas via polycondensation dicarbamates monomers with diols and diamines. [38][39][40][41] Inspired by these studies, we designed and synthesized a novel phosphorus-containing dicarbamates, di(N-carbomethoxyl-aminomethyl)benzyl phosphine oxide from THPS. Five phosphorus-containing polyureas were prepared by trans-ureation polycondensation of di-(N-carbomethoxylaminomethyl)benzyl phosphine oxide with five different diamines catalyzed by 1,5,7-triazabicyclododecene (TBD).…”