The effect of hexamethylene diisocyanate modified ALCELL lignin as a coupling agent on the flexural properties of oil palm empty fruit bunch – polypropylene composites

Abstract

ALCELL lignin has been employed as a coupling agent in oil palm empty fruit bunch (EFB)–polypropylene (PP) composites. The lignin has been chemically modified with hexamethylene diisocyanate (HMDI). Evidence for the reaction between HMDI and lignin has been observed by using Fourier transform infrared (FTIR) analysis. The effect of lignin as a coupling agent on the flexural properties has been studied. The results show that the HMDI‐modified lignin is able to impart greater compatibility between EFB and PP. This is reflected in the greater flexural strength shown by the composites with HMDI‐modified lignin than those with the unmodified lignin. Scanning electron microscopy studies show that HMDI‐modification of lignin results in a better blending and compatibility between lignin and PP matrix. The glass transition temperature of lignin increases as the level of HMDI modification is increased. © 2001 Society of Chemical Industry

Flour rice husk as filler in block copolymer polypropylene: Effect of different coupling agents

“…Because of its low polarity, it can be used as a coupling agent. 10 However, its degradation tempera-ture and mechanical properties are distinctly lower than the other natural filler components. 11 As shown in Table I, flour rice husk (FRH) is a special lignocellulosic material.…”

Surface modification of lignin for applications in polypropylene blends

“…They observed a 15–35% maximum increase in the impact strength with blending up to 40 wt % alkylated lignin; however, this was accompanied by a decrease in the tensile and flexural properties. Esterified lignin, with phthalic anhydride as a coupling agent, and maleic anhydride grafted low‐density polyethylene were used by some researchers to further enhance the interfacial bonding between the filler and the polymer resin . Attempts to use modified lignin itself as a biobased coupling agent for polyolefin composites have also been reported .…”

“…Esterified lignin, with phthalic anhydride as a coupling agent, and maleic anhydride grafted low‐density polyethylene were used by some researchers to further enhance the interfacial bonding between the filler and the polymer resin . Attempts to use modified lignin itself as a biobased coupling agent for polyolefin composites have also been reported . More recently, a study done by Buono et al .…”

“…Esterified lignin, with phthalic anhydride as a coupling agent, and maleic anhydride grafted low-density polyethylene were used by some researchers to further enhance the interfacial bonding between the filler and the polymer resin. 14 Attempts to use modified lignin itself as a biobased coupling agent for polyolefin composites have also been reported. [14][15][16][17] More recently, a study done by Buono et al 18 on the silylation and acetylation of soda lignin showed enhanced hydrophobicity, thermal stability, and better compatibility in silylated lignin compared to neat or Additional Supporting Information may be found in the online version of this article.…”

“…14 Attempts to use modified lignin itself as a biobased coupling agent for polyolefin composites have also been reported. [14][15][16][17] More recently, a study done by Buono et al 18 on the silylation and acetylation of soda lignin showed enhanced hydrophobicity, thermal stability, and better compatibility in silylated lignin compared to neat or Additional Supporting Information may be found in the online version of this article. acetylated ones when it was blended with low-density polyethylene.…”