Suitability of man made cellulose fibers as reinforcement for bio-based polymer composites

It has been demonstrated that natural fibers, such as flax and hemp for example, have mechanical properties competitive to those of glass fibers. This makes such fibers very goodpotential reinforcement for polymer composites. However, there are certain difficulties to utilize those properties on the extent that composites based on these fibers become alsocompetitive with synthetic materials in terms of mechanical performance. One of the problems is poor adhesion between matrix and fibers, which can be improved by additionalfiber treatment or by use of more compatible polymers (for example bio-based resins).Another issue is related to the length or the fibers and their orientation. Normally natural fibers are fairly short and thus it is difficult to maintain their pre-define orientation in thecomposite. Finally, maybe one of the biggest drawbacks of natural fibers is variability of their properties: quality of fibers will differ depending on location of growth and time of harvest.Moreover, large variability of properties can be observed even within the same batch of fibers. Sometimes these disadvantages can overshadow the main advantage of these materials– they are environmentally friendlier than synthetic materials and they are sustainable.Due to these concerns, the other type of reinforcement with plant origin (and high cellulose content, similar to flax and hemp fibers) has recently caught an attention as alternativereinforcement for bio-based composites - regenerated cellulose fibers. Although these are manmade fibers, they are made out of the natural polymer directly in contrary to the fibersmade out materials with fossil origin. These fibers are continuous and it is easy to arrange them into fabrics with stable orientation and geometry. These fibers have been discovered for more than a century ago but until now they have not been seriously considered for use in high performance polymer composites. At present the main application of these fibers is within textile industry and in tire processing.The current study focuses on characterization of regenerated cellulose fibers (namely Cordenka fibers) in order to evaluate them as perspective reinforcement for bio-based polymer composites. General mechanical performance, statistical strength distribution as well as viscoelastic behaviour of the Cordenka fibers are presented. Influence of moisture andtemperature on mechanical properties is also examined. Suitability of regenerated cellulose fibers as reinforcement for bio-based polymer composites is discussed.Godkänd; 2010; 20111005 (joffe