Volume 12 Issue 3

To gain a better understanding of the effect of the interactions between two biomass components (cellulose-lignin and xylan-lignin) on lignin-derived phenolic products, two analysis methods are introduced. With 3:1, 2:1, and 1:1 ratios of cellulose and lignin, and xylan and lignin, the mixtures were subjected to fast pyrolysis, which was carried out in a fixed-bed tubular furnace at 450 to 600 °C. The phenolic content in the bio-oils was analyzed by gas chromatography-mass spectrometry. The product distributions showed that cellulose, xylan, and lignin were the main contributors to the mass of biomass bio-oil, gas, and char, respectively. The char yields decreased and the bio-oil and gas yields increased in the presences of cellulose and xylan. Comparative analyses of both the phenol content and peak area of the two methods suggest that in the case of cellulose and lignin co-pyrolysis, the formation of three kinds of phenolic products is promoted. The strength of this positive effect increased with increasing lignin content. However, the production of hydroxyphenols is promoted, while the productions of guaiacols and syringols are inhibited by the effect of xylan, which creates a different interaction between xylan and lignin.

A new kind of thermoplastic elastomer nanocomposite reinforced with cellulose nanofibers has been reported. The aim of this investigation was to study the interaction and dispersion of cellulose nanofibers into the Pebax matrix. These copolymers are considered as polyether-b-amide thermoplastic elastomers. They are from renewable resources, and their hydrophilic character allows them to interact with nanocellulose. The interaction and reinforcement effect of nanocellulose at 3 levels of nanocellulose, (1%, 3%, and 5%), were examined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and other mechanical tests. The results achieved from these tests indicated appropriate effects of cellulose nanofibers for the strong interaction and close contact with the polyamide phase of the Pebax polymer via strong hydrogen bonding.

The swelling of natural porous materials, including bleached pulp, as represented by mathematical descriptions, is influenced by a variety of different operating factors. The formerly used Generalised Hygroscopicity Model leads to either a disproportion between a model and a limit value of the sorption capacity or to noticeable deviation in the early swelling phase. Alternatively, the so-called Simple Bounded Growth model solely depends on the maximum sorption capacity, ignoring the physical properties that affect the fibre swelling rate. This research shows that the combination of the two models best describes the swelling process of bleached pulp – a rapid swelling phase and a slower swelling phase. The combined model was found to be useful in characterizing the well-known hornification process.

This study aimed to improve the flame-retardant properties of laminated bamboo lumber (LBL) using phosphorus-nitrogen-boron flame retardants (FRs). The combination of a 7:3 ratio of monoammonium phosphate (MAP) and boric acid/borax compounds (SBX), and 74.32 kg/m3 of FRs (10.3% weight gain), exhibited enhanced fireproofing performance for LBL materials. A commercial flame retardant (guanylurea phosphate) (GUP) was systematically studied as a comparison. A cone calorimeter and a thermal analyzer were used to characterize the combustion behavior and thermal stability, respectively. The flame retardants morphology in bamboo cell cavities was investigated using scanning electron microscopy (SEM) and an energy dispersive X-ray analysis (EDXA). The results showed that at a heat flux of 50 kW/m2, the heat release rate and the total heat release of LBL samples treated with MAP-SBX flame retardants decreased more considerably than that of the untreated samples. The use of MAP-SBX not only promoted carbonization of LBL greatly but also indicated a good performance of smoke and combustion suppression as well as for the GUP. Flame retardants were confirmed to penetrate into the cell cavities of the bamboo using SEM and EDXA.

A biocomposite manufactured from peroxide/silane crosslinked poly(lactic acid) reinforced with hybridized empty fruit bunch (EFB) oil palm and cotton fibers was investigated. Optimization of dicumyl peroxide (DCP) and the vinyltrimethoxysilane (VTMS) crosslink system by using the 2k factorial design of experiment (DOE), with k = 2 was preliminary employed. There was no significant effect of the designed parameters, DCP(A) and VTMS(B), on the properties of the biocomposite. Concerning the environmental and economical aspects, the DPC and VTMS ratio was important. A crosslink agent content from 0.5 phr of DCP with 1 phr to 2 phr VTMS was recommended to manufacture a biocomposite with high heat distortion temperature (HDT) at above 100 °C and reasonable flow and mechanical properties. Also, the direct addition of the DCP/VTMS crosslink agent onto the PLA/rubber compound mixture and fed into a twin screw extruder for producing crosslinked PLA/EFB/cotton hybrid biocomposites were the optimized mixing methods. Shorter process line/time, ease of process steps, and reasonable engineering properties were justified. A HDT above 100 °C with a better toughness property of the biocomposite material was obtained. The PLA/PLA and PLA/ENR crosslinks via silane/moisture condensation during the sauna incubation was the prime explanation.