Modification of Coconut Fibers by Chemical Treatment

As mentioned previously, three different procedures for surface modification were applied to coconut fiber. According to Mohanty [23], chemical modification of coconut fiber can increase the compatibility (adhesion) between the fibers and the PP. By optimization of the interface between the fibers and the matrix, composites with good properties can be obtained. 

After treatment with water, there was a weight loss of 9.27% for the non-treated fiber, indicating that a small amount of soluble extractives is removed with water. The soluble extractives removed by water are typically carbohydrates, gums, proteins and inorganic salts. Santiago [24] shows that hot water treatment removes part of the waste material in the coconut fiber, without removing the internal components of the fiber, thus avoiding alterations of the fiber properties. 

After treatment with NaOH 2% (w/v), a weight loss of 17.93% was observed with respect to the initial weight of the fiber. Lignin and hemicellulose were partially removed from the fiber, promoting better packing of the cellulose chains. This leads to increased crystallinity of the fiber [1]. 

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