Chemical, biological, and nanoclay treatments for natural plant fiber-reinforced polymer composites: A review

Abstract

Natural plant fiber-reinforced polymer composites have been in the limelight in the field of materials science for their mechanical properties, economy, and eco-friendliness. Properties of such novel composites depend on the adhesion and interaction between the fibers and the polymer matrix. Consequently, poor interaction can lead to declined mechanical properties, particularly strength. Surface modifications of fibers are carried out to enhance the bonding with the matrix by certain chemical treatments that remove hydroxyl groups in the amorphous cellulose region, making them hydrophobic and hence compatible with the matrix. Doing so also strengthens the composites, widening their scope of application. This review article provides comprehensive information about various surface modification techniques that include alkali, silane, acetylation, permanganate, peroxide, benzoylation, acrylation, acrylonitrile grafting, isocyanate, addition of maleated coupling agents, and fungal treatments. The working mechanisms and the effects of such treatments on mechanical strength are also elucidated. Furthermore, this review provides an overview of nanoclay inclusion in polymers, their addition techniques, and the augmentation of the mechanical properties of polymer matrix composites. The article concludes along with the field of applications, summary of pertinent challenges, and directions for future work.

A Review on Natural Fiber Reinforced Polymer Composite for Bullet Proof and Ballistic Applications

“…The amorphous part of cellulose consist of multiple hydroxyl groups which impart a polar nature to the fiber which lead to a poor bonding with polymer matrix. Therefore, surface modification was subjected with the purpose of reducing the polar nature of the fiber by reducing/removing the hydroxyl groups and help to increase the fiber-matrix adhesion and enhance its mechanical properties [ 27 ].…”

Modification of Fibers and Matrices in Natural Fiber Reinforced Polymer Composites: A Comprehensive Review

“…In this newly developed approach, specific enzymes comes in contact with fiber surfaces there by leading toward elimination of non-cellulosic substances like waxes, lignin, and hemicelluloses from fiber surface. [336,337] Enzymes produced from white rot fungi eliminates the lignin and hemicelluloses and induces the hydrophobic tendency of fibers. Hyphane produced from fungi induces fine micro pores over fiber surfaces and provides better interlocking among fiber and polymer matrix.…”

Effect of aluminosilicate nanoclay on polyester composites' static and dynamic mechanical properties

“…[8] The majority of articles published on large aspect ratio layered silicates (nanoclay) in the polymer show adverse effects which result in advantageous properties. [9][10][11] But the addition of clay at higher levels in the polymer matrix results in agglomeration/aggregation, which reduces the effectiveness of the nanosized particles in the matrix, resulting in the weak properties of the specimens. [12] A recent study clearly shows that the ultrasonication technique is an effective method to disperse the nanoclay uniformly in the polymer matrix in order to increase the filler level to a higher content so as to increase the properties of the material to a higher extent.…”