Kraft lignin-based thermoplastics

Figure 5. Tensile behaviour to point of ftacture for 85% kraft lignin-based thermoplastic blends with poly(vinyl acetate) in presence of diethyleneglycol dibenzoate (1.6%) and indene (0.8%). Stress-strain a-e curves determined for material test pieces at strain rate of 4.5 x 10" sec" graphical data from reference 1.

Be that as it may, some important insight at the molecular level into the constitution of the 85% kraft lignin-based thermoplastics was furnished by a small modification to the formulation that had been developed for these blends. As already mentioned (see section 2.1), kraft lignin preparations are... 

The advent of 85% kraft lignin-based thermoplastics was an important development since it had been assumed until then that polymeric materials with such high lignin contents would be extremely weak — if, indeed, they were capable of retaining any measurable cohesiveness at all. However, the kraft lignin components in these new thermoplastics were still partially soluble in aqueous alkaline solution, and thus alternative formulations were sought to obviate dissolution in aqueous solutions of any kind. 

Li, Y., and Sarkanen, S., 2001, Kraft lignin-based thermoplastic polymer blends. In 11th International Symposium on Wood and Pulping Chemistry ATIP, Paris, Vol. I, pp. 75-78. 

---