Effect of fiber treatment

Van Fo Fy, G.A. (1967). A study of the effect of fiber treatment on stress distribution in glass-reinforeed plastie struetures. Prikladuaya Makhanika 3, 106-112. 

Jawaid, M., Alothman, 0. Y, Paridah, M. T., Khalil, H. P. S. A. (2013]. Effect of fiber treatment on dimensional stability and chemical resistance properties of hybrid composites,... 

Herrera-Franco, P.J., Aguilar-Vega, M.J. Effect of fiber treatment on mechanical properties of LDPE-henequen cellulosic fiber composites. J. Appl. Polym. Sci. 65, 197-207 (1997)... 

Cantero G. Arbelaiz A. Mugika F. Valea A. Mondragon L Mechanical behavior of wood/polypropylene composites Effects of fiber treatments and ageing processes. Journal of Reinforced Plastics and Composites, vol. 22, (2003), pp. 37-50. 

Figure 20.15 Effect of fiber treatment level on shear and impact properties with Fortafil 41 fiber/ERLA 4617-DDM epoxy resin system. Source Reprinted from Goan JC, Martin TW, Prescott R, 28th Ann Tech Conf Reinf Plast/Comp Inst 28, 21B, 1-4, 1973.

Rong M, Zhang M, Liu Y, Yang G, Zeng H (2001) The effect of fiber treatment on the mechanical properties of unidirectional sisal-reinforced epoxy composites. Compos Sci Technol 61 (10) 1437-1447... 

Effect of fiber treatment (untreated and alkali treated), fiber size (1, 2, and 4 mm), and fiber content (5,10, and 15% by weight) was investigated for jute fiber composites... 

Effect of fiber treatment Chemical modification of fibers decreased the dielectric constant of OPF-sisal fiber-NR hybrid composites [59]. This was due to the decrease in orientation polarization of the composites upon treatment. Chemical treatment results in reduction of hydrophilicity of the fibers leading to lowering of orientation polarization and subsequently dielectric constant. Alkali treatment yielded higher dielectric constant comparing to silane treatment. However, higher concentration of alkali... 

Effect of fiber treatments The hydrophobicity of OPF-PP composites enhanced upon E-43 treatment to the fiber and the effect of treatment was further enhanced by chemical loading [4]. The ability of maleic anhydride residue of E-43 to interact with hydroxyl groups of OPF, blocking the hydroxyl group-water hydrogen bonding and the hydrophobicity imparted by the PP chain of E-43 are the reasons for enhanced hydrophobicity. 

Effect of fiber treatments Both TDI treatment and hexamethylene diisocyanate (HMDI) treatment improved the tensile strength of OPF-PU composites [29]. At a fiber loading of 40% and NCO/OH ratio of 1.1, tensile strengths of 26 MPa, 30 MPa, 28 MPa were exhibited by untreated fiber composite, TDI-treated fiber composites and HMDI-treated fiber composites, respectively. The introduction of isocyanates from TDI or HMDI has enhanced the interaction between OPFs and PU matrix. 

Effect of fiber treatments Alkali treatment on OPFs significantly improved its interfacial shear strength in polyester matrix [14]. Alkali treatment washed out the outer skin, better exposing fiber to the polyester matrix, leading to proper interaction between their surfaces. In addition, the fine holes created on alkali treatment allowed the polyester to penetrate into the fiber bundles in a better way. Acetylation treatment to the fibers improved impact strength of OPF-polyester composites due to improved fiber wettability and resulting fewer void spaces [71]. The tensile stress of OPF-polyester composites increased slightly upon both acetylation and silane treatments on fibers and decreased upon titanate treatment [14]. The flexural modulus of OPF-PP composites also increased considerably upon acetylation treatment on fibers. Similarly the abrasion resistance of OPF-polyester composites was enhanced upon alkali treatment to fibers [13]. Treated fibers enhanced the adhesion resistance of polyester resin by 75-85%, while untreated fibers enhanced the abrasion resistance only by 50-60%. 

Effect of fiber treatments Acetylation treatment on fibers reduced the water absorption (at 100°C) of untreated OPF-polyester composites from 15.8% to 5.7%. Good interfacial contact between fiber and matrix and increased hydrophobicity caused by the treatment lead to reduced water absorption. 

Effect of fiber treatments The rate of water uptake by OPF-PF composites upon different fiber treatments was in the order extracted (highest) > non-extracted > propionylated > acetylated (lowest) [73]. The variation between the lowest and highest was 30%. It is also observed that most of the fiber treatments increased water absorption of the composites except alkali treatment, however the treatments reduced water absop-tion of the fibers [45]. Alkali treatment removes the amorphous waxy cuticle layer of the fiber and activates hydroxyl groups leading to chemical interaction between the fiber and matrix. In case of PF, the trend was different as it is hydrophilic whereas most polymers used for composite fabrication is hydrophobic. Therefore the more hydro-phobic the fiber in OPF-PF composites, less the extent of fiber-matrix interaction, which facilitate sorption process [23]. For example, latex coating make the fibers most hydrophobic and the OPF-PF composites prepared from latex coated fibers exhibit maximum water absorption. 

Effect of fiber treatments Alkali treatment of fibers slightly increased the density of composites as a result of low void content indicating better interfacial adhesion between matrix and fiber [39]. AlkaH treatment considerably reduced the porosity, indicating better fiber-matrix adhesion. The principal cause of increase in porosity in composites is the presence of voids in the fiber-matrix interface due to lack of compatibility. Study on water absorption characteristics of OPF-LLDPE composites [53] indicated alkali treatment on fibers reduced water absorption at higher fiber loadings of 40 and 50 percent. Composites made from alkaH-treated fibers exhibited more swelling compared to untreated fiber composites except at 50% fiber loading. Alkali treatment caused more linear expansion. 

Effect of fiber treatment The flexural strength of oil palm fiber-LLDPE composites increased with fiber content up to 20 percent and thereafter decreased in case of... 

Effect of fiber treatment Alkali-treated fiber caused higher crystallinity to the OPF-LLDPE composites [16], Higher CTE was observed for imtreated fiber composites than alkali-treated ones. 

C. A.S. Hill, and H.P.S.A. Khafil, Effect of fiber treatments on mechanical properties of coir or oil palm fiber reinforced polyester composites. J. Appl. Polym. Scie. 78, 1685-1697 (2000). 

Figure 4.13 Effect of fiber treatment on the flexural properties of neat PLA and kenaf/PLA laminated biocomposites. FIB, untreated kenaf FIBNA, alkali-treated kenaf FIBSI, silane-treated kenaf and FIBNASI, alkali-F silane-treated kenaf. (After M.S. Huda et al. [51].)...

The mechanical properties of the natural-fiber-reinforced composites are dependent of certain parameters, such as volume fraction of the fibers, fiber aspect ratio, fiber-matrix adhesion, stress transfer at the interface, and fibers orientation. Several studies on natural-fiber-reinforced composites involve mechanical property characterizations, such as the function of fiber content, effect of fiber treatments, and the use of coupling agents. 

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