Studies on jute-reinforced composites, its limitations, and some solutions through chemical modifications of fibers

Abstract

Jute, unlike other natural fibers, absorbs moisture and its moisture regain property is quite high. Water migration and subsequent degradation of jute-based composites can be a problem. Because jute is hydrophilic and the matrix resins are mostly hydrophobic, wetting of the fibers with resins is poor, for which high resin consumption may occur that would increase the cost of composites. To reduce the moisture regain property of jute fiber, it is essential to pretreat the jute fiber so that the moisture absorption is reduced and the wettability of the resin is improved. Jute fiber in the form of nonwoven jute has been pretreated with precondensate like phenol formaldehyde, melamine formaldehyde, cashew nut shell liquid-formaldehyde, and polymerized cashew nut shell liquid. The moisture content of the pretreated nonwoven jute has been determined by conventional methods and by a differential scanning calorimetric technique. Treatment of jute with precondensate causes the reduction of water regain property in jute. Pretreated nonwoven jute has been impregnated with phenol formaldehyde resin, and the composite board has been prepared therefrom. The jute composite board has been tested for bending strength, tensile strength, thickness swelling, and water absorption. Thermal analyses, such as differential scanning calorimetry and thermogravimetry, have also been conducted on jute and pretreated jute fibers.

Environment Friendly Composite Materials: Biocomposites and Green Composites

“…These structures contain reactive functional groups that are capable of bonding to the reactive groups in the matrix polymer. Thus modification of natural fibers is attempted to make the fiber hydrophobic and to improve interfacial adhesion between the fiber and the matrix polymer [57][58][59][60][61][62][63][64][65][66][67][68][69][70][71] . Chemical treatment of natural fibers has been reviewed where it reported 58 that such as de-waxing (de-fatting), de-lignifications, bleaching, acetylation, cynoethylation 72 , and chemical grafting were used for modifying the surface properties of the fibers for enhancing its performance.…”

“…The treatment resulted in an increase in de-bonding stress and thus improved the ultimate tensile strength up to 30%. Basak 71 , et al have reported that treatment of jute with poly-condensates such as phenol-formaldehyde, melamine-formaldehyde, and cashew nut shell liquid-formaldehyde improved the wettavbility of jute fibers and reduced the water regain properties. Treatment with cardanol-formaldehyde was also found to reduce water absorption and improved the mechanical properties of jute/polypropylene composite 73 material.…”

Jute/polypropylene composites I. Effect of matrix modification

“…Various fibre surface treatments have been reported, such as: alkali [4][5][6][7][8], silane [9][10][11][12][13], combination of alkali and silane [14,15], monomer grafting under UV radiation [16][17][18], maleic anhydride grafted polypropylene [19][20][21][22], and others [23][24][25][26][27][28]. Among those commercial coupling agent maleic anhydride grafted polypropylene (MAHgPP) has been found to be the most efficient in improving interfacial adhesion of natural fibres and a PP matrix [29][30][31][32][33][34][35][36][37][38].…”

A brief review on the chemical modifications of lignocellulosic fibers for durable engineering composites

“…The details of these procedures are described in the following paragraphs. PF resins (melamine formaldehyde, cashew nut shell liquid-formaldehyde, and polymerized cashew nut shell liquid) when applied on jute felt led to enhanced tensile strength and water repellence of composites manufactured from treated felt [80]. Decreased water uptake is attributed to cross-linking of LCFs and resin matrix through hydrogen bonds and subsequent development of weakly bonded networks connected through secondary bonds (Scheme 11a).…”