Effect of partial delignification of kenaf bast fibers for radiation graft copolymerization

Abstract

Malaysian kenaf bast fiber was treated by acidic chlorite to be applied for a trunk polymer radiation-induced graft copolymerization. The delignification conditions such as temperature, reaction time, and sodium chlorite (NaClO 2 ) loading were optimized from the viewpoints of density, tensile strength, and reactivity of grafting. It was found that delignification condition at 80 C for 6 h with 0.5% NaClO 2 gave 91% of lignin removal from the kenaf bast fibers. In this case, the density, fineness, and tensile strength of the kenaf fiber decreased about 46, 44, and 87%, respectively. Reactivity of grafting was evaluated using 4-chloromethyl styrene to obtain widely available precursor materials. The partial delignified kenaf with residual lignin less than 2% resulted in degree of grafting of 134%, which is enough for precursor materials.

Radiation-induced modifications in natural fibres and their biocomposites: Opportunities for controlled physico-chemical modification pathways?

“…10). Mohamed et al have also confirmed these results when they attempted to graft 4-chloromethyl styrene onto delignified kenaf fibres (Mohamed et al, 2013). However, Ali Ayoub et al have shown that lignin can be grafted by styrene monomer at low doses (Ayoub et al, 2014).…”

“…Khan and Khan reported that γ-irradiated jute fibres are better dispersed into PP (macro) molecule to be grafted is then added. The grafting occurs thanks to the radicals already formed on the fibre during irradiation (Mohamed et al, 2013;Sharif et al, 2013); (ii) the second pathway is known as the mutual grafting and can be used for "grafting-from" method: the fibre is impregnated with the molecule and then irradiated, leading to the grafting of the molecule on the fibre and its possible free radical polymerization (Kaur et al, 2010;Kodama et al, 2014;Sonnier et al, 2015). Desmet et al (Desmet et al, 2011) consider that mutual grafting is less detrimental for cellulose because solvent and monomer can act as stabilizers during irradiation.…”

Influence of lignocellulosic substrate and phosphorus flame retardant type on grafting yield and flame retardancy

“…Fiber micrographs were obtained using a scanning electron microscope (FE I Quanta 200). The fibers w ere o bserved u sing a vertical sample holder under high vacuum at a voltage of 12.5 kV and a working contradiction with literature, and especially works of Sharif et al [29] and Mohamed et al [30]. Nevertheless, these authors carried out preirradiation method while the mutual radiation grafting was chosen in the present work.…”

“…Mohamed et al [30] also studied the inhibitory effect of lignin with kenaf fibers. The kenaf fibers were delignified with sodium chlorite solution NaClO 2 before radiation grafting.…”

Radiation Processing of Polymer-based Nanomaterials

“…In general, the materials processing methods with the aid of physical effects, chemical effects and biology effects between high-energy radiation (such as gamma ray and electron beam) and matter is called radiation processing. At present, although the radiation processing obtain the very good application in many fields of polymwric materials [1][2][3][4][5][6][7][8][9][10][11][12][13], while the parathion of polymer-based nanocomposites via radiation technology is still a new field of polymer radiation processing.…”