Studies on adsorptive interaction between natural fiber and coupling agents

Abstract

Efficacy evaluation of various coupling-agent-treated sisal fibers was made by contact angle measurements and Fourier transform infrared spectroscopy. It was found that high contact angle and reduced hydroxyl groups on titanate-treated fibers favor its better hydrophobicity over the other treatments. The presence of adsorbed layer of coupling agent on the fiber surface was ascertained by appearance, shifting, and decreased intensity of absorption bands. The lowest polar component of surfacefree energy for N-substituted methacrylamide-treated fiber indicates the formation of ordered layers of its organofunctionality at the surface. The reason for enhanced interaction between sisal fiber and N-substituted methacrylamide is suggested by the formation of hydrogen bond, besides extracting a surface-active proton from the fiber surface by alkoxy group to form a covalent bond. An optimum treating condition of fiber for effective adsorptive interaction has been reported. The deposition of compound in the form of an aggregate on the fiber surface was also observed under scanning electron microscopy.

Materials in Automotive Application, State of the Art and Prospects

“…According to BMW, it is possible to manufacture bio-based composites that are as much as 40 percent lighter than equivalent injection-moulded plastic parts. [Singh 1998] One of the challenges posed by injection moulding natural-fibre composites is to produce pellets of a consistent quality. This has been explored by both North American and European injection moulding equipment suppliers through a process called direct long-fibre thermoplastic (D-LFT) moulding.…”

Natural Fiber Composites: A Review

“…By capping the hydroxyl groups this ratio can be reduced. There are several promising techniques that have been studied by various groups [4][5][6][10][11][12][13][14] . Among these treatments mercerization (alkaline) treatment has had the most reviews [4][5][6]10,11 .…”

“…Among these treatments mercerization (alkaline) treatment has had the most reviews [4][5][6]10,11 . Utilizing silanes as coupling agents is a treatment commonly used in glass composite production and is starting to find uses in natural fiber composites 4,6,10,12,13 . Acetylation is another treatment that is common with cellulose to form a hydrophobic thermoplastic and has the potential to have the same results on natural fibers 4,5,6,14 .…”

Hybrid polymer networks of unsaturated polyester–urethane as composite matrices for jute reinforcement

“…Typically, such composites are prone to micro‐cracking and secondary bond failures (delamination) because of poor toughness and high volume shrinkage during curing process of the polyester resins 4, 9, 10. Therefore, improvements in the physical and mechanical properties of polyester resin are highly desirable by making it tougher11, 12 and creating an optimum adhesion with the fibers 13, 14. In recent years, the hybrid polymer networks derived from unsaturated polyester and isocyanates have been recognized for this purpose to enhance the mechanical performance of the polyester resins 15–19.…”

“…4,9,10 Therefore, improvements in the physical and mechanical properties of polyester resin are highly desirable by making it tougher 11,12 and creating an optimum adhesion with the fibers. 13,14 In recent years, the hybrid polymer networks derived from unsaturated polyester and isocyanates have been recognized for this purpose to enhance the mechanical performance of the polyester resins. [15][16][17][18][19] It can be formed through the crosslink reactions, i.e., copolymerization of unsaturated polyester resin with styrene and polyaddition between terminal hydroxyl groups of polyester and isocyanate groups.…”