Volume 7 Issue 4

A cross-linked biomass-polymer composite with a lignin content of up to 60% was prepared by blending lignin with an epoxy resin and polyamine using a hot press molding process. The characteristics of the curing reaction of lignin with epoxy resin were studied using DSC and FTIR analysis. The effect of molding temperature and molding pressure on the mechanical properties and microstructure of the lignin/epoxy resin composite was also studied by SEM, DMA, and TG analyses. The results showed that the epoxy resin can be cured by lignin, and the curing temperature for the blends can be reduced by the introduction of a polyamine cure agent. The properties of the composite, such as bending strength, impact strength, glass-transition temperature, and thermal stability, were evidently influenced by the molding process. A good interfacial combination was formed between lignin and epoxy resin. Increasing the molding temperature and pressure proved beneficial to achieve a better interfacial combination for the composite, and the degree of ductile fracture was increased in the fracture surface of the composite.

Nanofibrillated cellulose, NFC, is an interesting wood fibre-based material that could be utilized in coatings, foams, composites, packages, dispersions, and emulsions, due to its high tensile strength and barrier properties, light weight, and stabilizing features. To improve applicability and properties of NFC, modification of its surface properties is often needed. In this study, the applicability of laccase-aided surface modification with hydrophobic dodecyl gallate (DOGA) on unbleached NFC was investigated. Also, laccase-catalyzed polymerization of DOGA and other phenolic compounds with lignin moieties was investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS). NFC modified with T. hirsuta-based laccase and DOGA showed decreased hydrophilicity, as compared with the native NFC, when coated on a paper surface. When dried as free-standing films, the surface properties of chemo-enzymatically modified NFC resembled those of the native NFC. The effect of modification was thus greatly influenced by different surface formation in differently prepared samples. Also, changing of the dispersion properties of DOGA by enzymatic polymerization affected the surface properties of the dried NFC samples. Covalent bonding between DOGA and NFC was not the main factor affecting the surface properties of the NFC in free-standing films or coatings.

Wavelet neural networks (WNNs) were used to investigate the influence of operational variables in the soda-ethanol pulping of oil palm fronds (viz. NaOH concentration (10-30%), ethanol concentration (15-75%), cooking temperature (150-190 ºC), and time (60-180 min)) on the resulting pulp and paper properties (viz. screened yield, kappa number, tensile index, and tear index). Performance assessments demonstrated the predictive capability of WNNs, in that the experimental results of the dependent variables with error less than 6% were reproduced, while satisfactory R-squared values were obtained. It thus corroborated the good fit of the WNNs model for simulating the soda-ethanol pulping process for oil palm fronds.

The byproducts of palm oil production (nut shells, fibers, and EFB) were combusted to obtain organic waste nanofillers. The prepared nano-filler was characterized by different techniques, viz. XRD for degree of crystallinity, particle size, morphology, and spectroscopic methods. The average diameter found was between 93.39 and 192.20 nm, and the width was between 18.17 and 43.45 nm. The SEM images revealed various morphological arrangements of particles. XRD studies exhibited crystalline nature of both the raw and ground nanofillers. The elemental analysis of nanofillers was carried out by EDX, and FT-IR was used to assign the degree of stretching of various functional groups. In addition to C, N, and O, elemental analysis revealed the presence of Al, Mg, Si, P, K, Ca, Fe, S, Ti, and Mn.

Microstickies in whitewater have caused serious deterioration of paper quality and low efficiency of paper machine runnability. To solve this problem it is necessary to master the characteristics of various aspects of microstickies. In this study, the physicochemical properties and size distribution of microstickies in whitewater of three typical kinds of waste papers, old newspaper (ONP), old book paper (OBP), and mixed office wastepaper (MOW), were investigated by conventional methods and a modified Flow Cytometry Method (FCM). The results showed that white water microstickies in different kinds of waste paper have different characteristics. This is a premise for analyzing stickies problems. Furthermore, in a certain kind of waste paper, the physicochemical properties and the direct determination of size and number of microstickies particle in whitewater can be combined together and taken as a whole to account for more phenomena or deduce more mechanisms, such as agglomeration and deposition, etc.

The maximum deformation and the stress state of furniture doors with different configurations of hinges were analyzed using finite element analysis with the ultimate purpose of optimizing the hinge configuration. The results showed that the maximum deformation decreased when the end distance ratio (Tp) also decreased. It was concluded that the end distance ratio (Tp) should not be greater than 1/8 when two hinges are mounted. The maximum deformation decreased when the number of mounted hinges was more than two. It is suggested that the number of mounted hinges is three when the dimensions of a furniture door are within normal values, considering the limitations in precision of processing and location. The maximum deformation was least when the middle hinge spacing ratio (Sp) was 1/3 and the mounting hinge number was four. The von Mises stress distribution was uniform within the door, and stress concentration only occurred in the vicinity of the mounted hinges. A material with high modulus of elasticity could contribute to minimizing the maximum deformation.

Two hemicellulose fractions were obtained by extraction of one-month- old young bamboo (Phyllostachys pubescens Mazel). The fractionation procedure employed 2% NaOH as extractant, followed by filtration, acidification, precipitation, and washing with 70% ethanol solution. The total yield was 26.2%, based on the pentosan content in bamboo. The physicochemical properties were determined and sugar composition analysis showed that the hemicelluloses consisted mainly of xylose, arabinose, galactose, and a small amount of uronic acid. Furthermore, based on FT-IR and NMR spectra analyses, the structure of hemicelluloses was determined to be mainly arabinoxylans linked via (1→4)-β-glycosidic bonds with branches of arabinose and 4-O-methyl-D-glucuronic acid. The molecular weights were 6387 Da and 4076 Da, corresponding to the hemicelluloses HA and HB. Finally, the thermal stability was elucidated using the TG-DTG method. The obtained results can provide important information for understanding young bamboo and the hemicelluloses in it.

This paper deals with the product design, engineering, and material selection intended for the manufacturing of an eco-friendly chair. The final product is expected to combine design attributes with technical and legal feasibility with the implementation of new bio-based materials. Considering the industrial design, a range of objectives and trends were determined after setting the market requirements, and the final concept was proposed and modeled. The product geometry, production technology, and legal specifications were the input data for product engineering. The material selection was based on the technical requirements. Polypropylene (PP) composite materials based on coupled-fiberglass, sized-fiberglass, and coupled-stone ground wood reinforcements were prepared and characterized. Final formulations based on these PP composites are proposed and justified.

High-density wood is required in wood flooring, especially in engineered wood flooring (EWF) designed for heavy-duty applications. However, high-density wood resources are limited and their cost is high. A densification treatment makes it possible for low- or moderate-density woods to replace harder species by modifying them into high-performance and high-value products, such as engineered wood flooring for heavy-duty applications. The general objective of this study was to develop a prototype of engineered wood flooring using sugar maple hygro-thermally densified surface layers. The results showed that thin sugar maple lumber densified at 200 °C under the combined effects of steam, heat, and pressure with a heat-resistant fabric had great potential for the manufacturing of engineered wood flooring for heavy-duty use. As a result of treatment, it acquired high density, improved mechanical properties, and it had a relatively high dimensional stability and an attractive color. Tests in conditioning rooms showed that the EWF with a densified sugar maple (Acer saccharum March.) surface layer presented the lowest amplitude distortion between the dry and humid conditions compared with the standard EWF (0.15 mm vs. 0.17 mm and 0.25 mm).

In this study, the impact bending strengths and specific impact bending strengths were determined for solid wood and laminated veneer lumber (LVL) produced from eucalyptus (Eucalyptus grandis W. Hill ex Maiden), poplar (Populus x euramericana I-214), and beech (Fagus orientalis L.) woods using urea formaldehyde (UF), melamine urea formaldehyde (MUF), and phenol formaldehyde (PF) adhesives. The tests were conducted in the flatwise and edgewise directions. In addition, specific impact bending strengths were calculated. Three-way ANOVA test results indicated that the effects of the species of tree and the direction of the load on the impact bending and specific impact bending were statistically significant. The type of adhesive was found to be insignificant. In addition, the results showed that impact bending strengths of solid beech and eucalyptus woods were greater than those of LVLs made of beech and eucalyptus, and no statistical differences were determined between solid poplar wood and LVL made of poplar.