Pineapple leaf fiber: A high potential reinforcement for green rubber and plastic composites

Pineapple is grown worldwide and after every second or third fruit, the field is “knocked down,” and a new growing cycle begins. The residues left in the field are pineapple leaves and stems. Pineapple leaves are sources of high quality natural fiber which has long been used in crafts and textile but are still left underutilized. Considering the present situation, its availability and mechanical properties, pineapple leaf fiber (PALF) has many potential applications. Recently our research group has developed a method to extract short and fine PALF from leaf waste. PALF was used to reinforce different types of rubbers to produce rubber composites with very high stretching stress at low elongations. Rubber reinforcements using hybrid or combination of PALF/silica and PALF/carbon black were also studied and very promising results were obtained. For plastic reinforcement, both PALF and non-fibrous material (NFM) were tested on polypropylene in order to fully utilize the leaf waste. The use of PALF and NFM also offers a new way to ‘greening’ plastic composites for performance and cost effectiveness. In the last part, it is shown that nonwoven mats made from either whole ground pineapple leaves or PALF can be used as reinforcements for unsaturated polyester and acrylic resin.