Synthesis and properties of biodegradable waterborne polyurethane modified as castor oil

Castor-oil biobased foam: the effect of the composition on the physical and mechanical properties via a statistical mixture design

“…Only sample C2 exhibited a slightly stronger intensity of isocyanate vibration band compared to the other samples. 23 The disappearance of this band ( Fig. 12a ) serves as evidence that nearly all the isocyanate has reacted with the hydroxyl groups of the polyol during the polymerisation process, resulting in the formation of urethane bonds as described in the following chemical reaction mechanism pathways.…”

“…12a) serves as evidence that nearly all the isocyanate has reacted with the hydroxyl groups of the polyol during the polymerisation process, resulting in the formation of urethane bonds as described in the following chemical reaction mechanism pathways. 20,23,24…”

“…In addition, an asymmetric band and a shoulder band at 1702 cm −1 are observed in all samples, providing evidence of hydrogen bond formation between the polyurethane chains. 20,23 Stretching and deformation vibrations related to the CH 2 and CH 3 groups present in the starting materials are observed at 2922 and 2852 cm −1 and 1460-1370 cm −1 , respectively 20 (Fig. 14a).…”

“…12a) serves as evidence that nearly all the isocyanate has reacted with the hydroxyl groups of the polyol during the polymerisation process, resulting in the formation of urethane bonds as described in the following chemical reaction mechanism pathways. 20,23,24 (i) Autocatalyzed reaction between polyols and isocyanate. The mechanism of the autocatalyzed reaction between polyols and isocyanate involves several steps.…”