Impact of Layer-by-Layer Self-Assembly Clay-Based Nanocoating on Flame Retardant Properties of Sisal Fiber Cellulose Microcrystals

Abstract

The renewable cationic polyelectrolyte chitosan (CH) and anionic nanomontmorillonite (MMT) layers were alternately deposited on the surface of sisal fiber cellulose microcrystals (SFCM) via layer-by-layer (LBL) self-assembly method. The structure and properties of the composites were characterized by zeta potential, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectrometer (FTIR), microcalorimeter (MCC), and so forth. The zeta potential results show that the cellulose microcrystalline surface charge reversed due to the adsorption of CH and MMT nanoplatelets during multilayer deposition. MMT characteristic diffraction peaks appear in XRD patterns of SFCM(CH/MMT)5and SFCM(CH/MMT)10composites. Additionally, FESEM reveals that the SFCM(CH/MMT)10surface is covered with a layer of material containing Si, which has been verified by elemental analysis. TGA results show that the initial decomposition (weight loss of 5%) temperature of SFCM(CH/MMT)5is increased by 4°C compared to that of pure SFCM. On the other hand, carbon residue percentage of SFCM(CH/MMT)10is 25.1%, higher than that of pure SFCM (5.4%) by 19.7%. Eventually, it is testified by MCC measurement that CH/MMT coating can significantly reinforce the flame retardant performance of SFCM.

A review on the extraction of pineapple, sisal and abaca fibers and their use as reinforcement in polymer matrix

“…The coated LbL thus acts as interphase and improves the fiber/matrix interaction. LbL technique was found to improve the properties of natural fibers such as its strength [84,85], wettability [86], flame retardant efficiency [87], antibacterial property etc. Battegazzore et al [85] modify the surface of hemp fibers using chitosan and sepiolite (CH/SEP) and found significant improvement in the mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/hemp fibers biocomposites.…”

Applications of Lamellar Membranes Reconstructed from Clay Mineral-Based Nanosheets: A Review

“…131 Wei et al also reported improvements in the thermal properties of highly flammable cellulose microcrystals (sisal fiber) after coating of chitosan and MMT layers. 132 Furthermore, the flame retardant properties of the MMT and rGO (MMT-rGO) membrane prepared by the vacuumassisted self-assembly process were reported by Liu et al 133 As shown in Figure 20a, when the MMT-G was subjected to an open flame, it burned in a flash due to the presence of residual oxygen groups. However, the flash was instantly selfextinguished with very slight deformations (Figure 20b).…”

“…Song et al observed that thinner MMT nanosheet membranes were more efficient in terms of the flame retardancy of PU foam . Wei et al also reported improvements in the thermal properties of highly flammable cellulose microcrystals (sisal fiber) after coating of chitosan and MMT layers …”