Preparation and Evaluation of Green Composites Using Modified Ammonium Lignosulfonate and Polyethylenimine as a Binder

Abstract

Modified ammonium lignosulfonate (MAL) and polyethylenimine (PEI) were combined and used as a binder in the manufacture of a woodbased green composite. The effects of hot pressing temperature (150 ºC to 190 ºC), hot pressing time (3 min to 11 min), binder content (10 wt.% to 30 wt.%), and MAL/PEI weight ratio (1:1 to 1:9) on the physicomechanical properties of the composites were investigated. The composites met the mechanical property requirements for furniture grade medium density fiberboard (MDF-FN REG) under the following parameters: hot pressing temperature of 170 ºC, hot pressing time of 7 min, binder content of 20 wt.%, and MAL/PEI weight ratio of 7:1. Under optimum processing, although the X-ray diffraction analysis showed that the addition of either unmodified ammonium lignosulfonate (UMAL) or MAL did not change the crystalline structure, this addition markedly improved the relative crystallinity of the composites in comparison to that of pure wood fiber. The DMA results indicated that the MAL/PEI composites had higher storage modulus and tanδ values than did the UMAL/PEI composites. Moreover, SEM analysis showed that the MAL/PEI composites had better bonding strength characteristics than did the UMAL/PEI composites.

Preparation of Biocomposites using Sawdust and Lignosulfonate with a Culturе Liquid of Levan Producer Azotobacter vinelandii as a Bonding Agent

“…As can be seen in Fig. 1a (vibrations of carboxyl group and -C=C bond in the benzene ring); 1400 cm -1 (belonging to CH3); and 2926 and 2860 cm -1 (aliphatic bonds) (Mohamad Ibrahim et al 2003;Savitsky et al 2012;Ahmed-Haras et al 2013;Klapiszewski et al 2013;Yuan et al 2014).…”

“…Taking into account earlier studies and scientific data (Semochkin and Pashkov 2002;Kadimaliev et al 2012;Privas and Navard 2013;Yuan et al 2014;Kadimaliev et al 2015), the following ratios of LGS to sawdust were chosen: 30:70; 50:50; 60:40; and 70:30 g/g. For monitoring, we used biocomposites derived without the addition of LGS as a control sample.…”

“…A number of authors suggest carrying out a preliminary modification of the LGS and sawdust by oxidation, adding other materials along with LGS, or using other polymers that have adhesive properties to both wood particles and LGS (Liu and Li 2006;Hu et al 2011;Hu and Guo 2013;Klapiszewski et al 2013;Yuan et al 2014) for this purpose. However, these methods demand a great amount of preliminary work and are labor-intensive.…”

“…At high temperatures, lignosulfonates are capable of participating in condensation polymerization reactions (Brovko et al 2009;Dumitrescu et al 2013;Akchurina 2014). These properties enable LGS to be used as a bonding agent in the production of various materials derived from vegetable waste (Laemsak and Okuma 2000;Privas and Navard 2013;Yuan et al 2014). However, the technology to use LGS to derive woodchip boards possessing high durability and humidity resistance has not yet been developed.…”

“…This structure, in the form of polyaromatic chains that include functional groups, defines the oil and water sensitive character of lignosulfonates and their surface, adsorption and adhesion activity. The surface activity is shown at high concentrations of LGS (Wu et al 2010;Vishtal and Kraslawski 2011;Peng and Zhang 2012;Savitsky et al 2012;Privas and Navard 2013;Yuan et al 2014).…”