Alkoxylation Polyfunctional

Reactions of alkoxylated lignin with diisocyanates produce thermoset materials because the lignin polyol is always polyfunctional with a functionality greater than 2. The isocyanate-alcohol reaction produces a urethane linkage that when repeated creates a crosslinked, nonreformable polyurethane. This is shown in Fig. 6. A broad spectrum of lignin-based urethanes have been made and tested. The data show that these materials match if not exceed the properties of synthetic polyurethanes made without lignin [60]. 

Generally, the polymerisation conditions for polyfunctional polyol alkoxylation, with KOH as catalyst, to rigid polyether polyols are ... 

Chem. Descrip. Amine-based polyfunctional alkoxylate Ionic Nature Nonionic... 

---

See also in sourсe #XX -- [ ]

---