Cellulose as made by plants is a complex material that mankind has used for all kinds of applications for millennia. Only in the 20th century synthetic materials increasingly replaced it, mainly because the plastics can be tailored to any material property required. Now, however, as plastic waste is becoming a global problem and sustainable solutions are in high demand, researchers are rediscovering cellulose and stripping down its complexity, resulting in so-called nanocellulose. With these structural building blocks of natural cellulose, they can then construct composite materials to rival the synthetic ones.
I've written a feature about nanocellulose which is out in the December issue of Chemistry & Industry:
Nature's building blocks
Chemistry & Industry December 2014, pp 18-21
(premium content, but I can send PDF "reprints" on request)
On page 51 of the same issue you'll find my review of the book "The economic competitiveness of renewable energy - pathways to 100% global coverage, by Winfried Hoffmann.