Mankind currently produces polymers in amounts similar to cast iron, steel, and colour metals all together if calculating production of polymers not by weight, but by volume. One can say, that mankind currently lives in a Polymer Age. Special emphasis should be given to biopolymers since they can offer properties similar to those of oil-based polymers with the added value of their extraordinary ability to be introduced in biological cycles with production of new raw materials for new polymers. This book presents current research in the area of bio-based polymers and sustainable composites.