Lignin-based polymeric materials

The advent of lignin-based polymeric materials as putative engineering plastics represents one of several technological... 

Lignin utilization studies have been conducted in several fields. However, no practical, commercial process has yet emerged for the manufacture of lignin-based polymeric materials. This is undoubtedly related to such factors as product inhomogeneity, reactivity differences, and also with lack of familiarity with this type of raw material. It should be also stressed that lignins are only by-products from pulp manufacture. However, the utilization of lignins in polymeric materials seems to be possible. 

Figure 7. Progressive plasticization of methylated higher molecular weight kraft lignin-based polymeric material by poly (butylene adipate). Stress-strain o-s curves determined for blends at strain rate of 9.3 x 10 sec. ...

Two papers point to the use of renewables in the production of interesting polymeric materials based on renewables. The contribution from Kelley describes a model compound study on the reactivity of pyrolysis oils, and how this information can be used in the formulation of new renewables based adhesives. Glasser describes the use of steam explosion technology to facilitate the simultaneous production of lignin and cellulose esters, useful in the production of thermoplastic structural polymers from wood. 

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. 

Biodegradable Hybrid Polymeric Materials Based on Lignin and Synthetic Polymers... 

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