Synthesis and characterization of elastomeric, biobased, nonisocyanate polyurethane from natural rubber

Abstract

Linear and crosslinked polyhydroxyurethanes (PHUs) based on natural rubber (NR) were synthesized by a polyaddition reaction without a solvent or catalyst to exploit the reactivity of diamines or triamines with dicyclic carbonate groups. Oligoisoprenes were obtained from the controlled oxidative degradation of NR and successive modifications of the chain ends. The syntheses of linear PHU were carried out with two approaches. The first one consisted of a reaction between amino telechelic oligoisoprenes and aromatic or aliphatic dicyclic carbonates. The second approach proceeded through a reaction between oligo-isoprenes bearing cyclic carbonate chain ends and difunctional or trifunctional amines. The evolution of these reactions was studied by Fourier transform infrared spectrometry. The influence of the carbonate-to-amine molar ratio, the chain length of the oligo-isoprenes, and the reaction temperatures were investigated. The thermal properties of the PHUs were studied by differential scanning calorimetry and thermogravimetric analysis.

Novel high reactive bifunctional five- and six-membered bicyclic dicarbonate – synthesis and characterisation

“…8 Due to the increasing environmental concerns linked with the stringent regulations of the European Union to ensure a high level of protection of health and the environment and the limitations in the use of isocyanates as a raw materials for conventional polyurethanes synthesis, PHU based on fossil or bio-based raw materials have been gain on importance. [25][26][27][28] For the rst time, we report a one-step procedure for the synthesis of novel and unknown derivatives of diglycerol, bifunctional bicyclic dicarbonate bearing ve-membered and six-membered functional groups, a,b-diglycerol dicarbonate (56BCC). The described procedure allows the synthesis of bicyclic dicarbonate with good yields from an easily available starting material, commercially available diglycerol.…”

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO2 Utilization

“…[65d] To rkelson and co-workers, in astudy on the preparation of segmented PHUs, used TBAI as catalyst at 80 8Cu nder CO 2 bubbling for 24-36 h. The addition of N,N-dimethylacetamide (DMAc) during reactionp revented solidification of the mixture. [121] Additional aromatic rigid building blocks 4c and 4d were used by Torkelson and co-workers for preparing carbonate-based hard segmentsi nP HU thermoplastics. [119] TA derivative 4b was earlier synthesized by Endo and co-workersb yc oupling GD and terephthaloyl chloride (TC) followed by carbonation at 100 8Ci n NMP with LiBr as catalyst.…”

“…[120] In more recent studies on the preparation of isocyanate-free thermoplastics, 4b was prepared by couplingo fG Cand TC. [121] Additional aromatic rigid building blocks 4c and 4d were used by Torkelson and co-workers for preparing carbonate-based hard segmentsi nP HU thermoplastics. [118,122] These monomersw ere synthesized from the corresponding glycidyl bisepoxide by using TBAI as catalyst at 80 8C.…”

Perspective: green polyurethane synthesis for coating applications

“…The production of glycerol carbonate from glycerol represents an interesting valorization of this molecule, which is industrially available and often considered as a by‐product . In this context, glycerol carbonate has been transesterified with pripol (a dimer fatty acid), with modified oligoisoprenes derived from natural rubber and with undecanoic acid (a vegetable oil derivative) . The opening of five‐membered cyclic carbonates by amines is generally very slow, requiring several days at room temperature.…”

“…73 In this context, glycerol carbonate has been transesterified with pripol (a dimer fatty acid), with modified oligoisoprenes derived from natural rubber and with undecanoic acid (a vegetable oil derivative). [74][75][76] The opening of five-membered cyclic carbonates by amines is generally very slow, requiring several days at room temperature. This reactivity is increased at elevated temperatures but side reactions are observed.…”