Materials of cellulose derivatives and fiber-reinforced cellulose-polypropylene composites: Characterization and application*
Peter Zugenmaier
Institute of Physical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Strasse 4, D-38678 Clausthal-Zellerfeld, Germany
Abstract: Cellulose is a biodegradable polymer produced sustainably in large quantities by nature. It has been used by mankind for centuries because of its favorable properties, but suffers disadvantages such as the high cost of production and limited processibility. For example, it cannot be melted and is only soluble in less common solvents. The latter limitation can be overcome through appropriate derivatization of cellulose, which increases the solubility range and may generate thermoplastic materials. This paper will review three new developments leading to enhanced utilization of cellulosics.
Firstly, an overview is given of the progress in the formulation of fiber-reinforced thermoplastic cellulose composites to facilitate extrusion processing. Cellulose-polypropylene composites show enhanced properties in comparison with neat polypropylene, and offer scope for replacing composites containing glass fibers, owing to resultant advantages in weight, recyclability, and ease of disposal. Progress is also reported in improving the predictability of essential physical quantities and melt flow in cellulose esters. Finally, an account is given of the successful development of microcrystalline cellulose (CFM) derivatives, synthesized in a heterogeneous manner, as chiral recognition agents in liquid chromatography. The structural features of these materials are decisive for their use. A model is proposed for the morphology of the cellulosic fibrils.
Keywords: cellulose-polypropylene composites; cellulose mixed esters; chiral recognition; model of cellulosic fibrils; DMTA; conformation and packing of cellulose tribenzoate.
*Paper based on a presentation at the 15th International Symposium on Fine Chemistry and Functional Polymers (FCFP-XV) and the 1st International Symposium on Novel Materials and Synthesis (NMS-I), 17-20 October 2005, Shanghai, China. Other presentations are published in this issue, pp. 1803-1896.