Interfacial interactions between urea formaldehyde and cellulose nanofibrils (CNFs) of varying chemical composition and their impact on particle boards manufacture (PBs)

2021 ◽  
Author(s):  
Maria C. Iglesias ◽  
Philip S. McMichael ◽  
Osei A. Asafu-Adjaye ◽  
Brian K. Via ◽  
Maria S. Peresin
Keyword(s):  
Chemical Composition ◽  
Building Materials ◽  
Colloidal Stability ◽  
Low Cost ◽  
Urea Formaldehyde ◽  
Cellulose Nanofibrils ◽  
Global Market ◽  
Modulus Of Rupture ◽  
Superior Performance ◽  
Interfacial Interactions

Abstract Wood-based panels are commonly used as building materials for interior and exterior purposes. Their production and utilization have increased over the past decades due to the useful properties they present. Adhesive-bonded products make up to 80% of the wood alternatives on the global market, and of that, urea-formaldehyde (UF) makes up approximately 81% of the resins used. Formaldehyde-based resins are used due to their effectiveness and low cost, as well as their ease of application and lack of color. Nevertheless, their main disadvantages are the lack of tackiness and the emission of formaldehyde over time. To improve UF performance, the utilization of microfibrillated cellulose, has been demonstrated to be effective. However, more understanding on the mechanisms of the interactions is of relevant importance. In this work, we studied interfacial interactions between UF with bleached (BCNF) and unbleached (LCNF) cellulose nanofibrils using Quartz Crystal Microbalance with dissipation monitoring (QCM-D) technique observing the superior performance of lignin-containing CNF. Additionally, the surface free energies were investigated using Contact Angle Measurements (CA) showing a decrease of the values mainly when utilizing LCNF, which was later correlated with the wettability properties of the particle boards (PBs). PBs with different adhesive/CNF formulations were produced showing larger improvements when adding LCNF in terms of modulus of elasticity (MOE), modulus of rupture (MOR), and internal bonding (IB). To gain a better understanding on the interactions between CNF and UF, CNF was fully characterized in terms of morphology, chemical composition, charge density, as well as thermal and colloidal stability.

scholarly journals Coconut Fibre and Sawdust as Green Building Materials: A Laboratory Assessment on Physical and Mechanical Properties of Particleboards

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 256
Author(s):  
Dg Normaswanna binti Tawasil ◽  
Eeydzah Aminudin ◽  
Nor Hasanah Abdul Shukor Lim ◽  
Nik Mohd Zaini Nik Soh ◽  
Pau Chung Leng ◽  
...  
Keyword(s):  
Physical Properties ◽  
Building Materials ◽  
Mechanical Performance ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Green Building ◽  
Modulus Of Rupture ◽  
Laboratory Assessment ◽  
Press Temperature ◽  
Coconut Fibre

This paper evaluates, via a laboratory assessment, the physical properties (BS EN 323:1993, BS EN 324) and mechanical performance (BS EN 310: 1993) of hybrid particleboards using agricultural wastes, namely coconut fibre and sawdust. The process begins with the preparation of the materials where they are sieved and retained with the 5-mm sieve and then oven-dried. The hybrid particleboard mixed with the addition of resin (urea formaldehyde) was sprayed and hot pressed. The hot press temperature was set at 180 °C, with the resin content of 8 wt.% and the design density of 650 kg/m3 used in producing the particleboard. The percentage/ratio of the composition of sawdust (SD) to coconut fibre (CF) varied ranging from 100SD:0CF to 70SD:30CF, 50SD:50CF, 30SD:70CF, and 0SD:100CF. Meanwhile, as for the thickness of the boards, it was categorised into three groups which are 16 mm, 20 mm, and 32 mm. The particleboards were conditioned to the room temperature for seven days before being tested for physical properties and mechanical performances. The results show that the most optimum composition of sawdust to coconut fibre is 0% sawdust to 100% coconut fibre (0SD: 100CF) and the optimum thickness is 20 mm, where its density is 761.99 kg/m3, swelling thickness is 11.98%, and water absorption at 37.64%. With the modulus of elasticity of 1510 N/mm2, the modulus of rupture of 17.8 N/mm2, and the internal bonding of 1.08 N/mm2, they satisfied the universal standard of Particleboard Type P3 of BS EN 312:2010.

scholarly journals Potential of Brewer’s Spent Grain as a Potential Replacement of Wood in pMDI, UF or MUF Bonded Particleboard

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 319
Author(s):  
Marius Cătălin Barbu ◽  
Zeno Montecuccoli ◽  
Jakob Förg ◽  
Ulrike Barbeck ◽  
Petr Klímek ◽  
...  
Keyword(s):  
Internal Bond ◽  
Mechanical Performance ◽  
Animal Feed ◽  
Urea Formaldehyde ◽  
Modulus Of Rupture ◽  
Brewer’S Spent Grain ◽  
Beer Brewing ◽  
Removal Of Heavy Metals ◽  
Dry Conditions ◽  
Spent Grain

Brewer’s spent grain (BSG) is the richest by-product (85%) of the beer-brewing industry, that can be upcycled in a plentiful of applications, from animal feed, bioethanol production or for removal of heavy metals from wastewater. The aim of this research is to investigate the mechanical, physical and structural properties of particleboard manufactured with a mixture of wood particles and BSG gradually added/replacement in 10%, 30% and 50%, glued with polymeric diisocyanate (pMDI), urea-formaldehyde (UF) and melamine urea-formaldehyde (MUF) adhesives. The density, internal bond, modulus of rupture, modulus of elasticity, screw withdrawal resistance, thickness swelling and water absorption were tested. Furthermore, scanning electron microscopy anaylsis was carried out to analyze the structure of the panels after the internal bond test. Overall, it was shown that the adding of BSG decreases the mechanical performance of particleboard, due to reduction of the bonding between wood and BSG particles. This decrease has been associated with the structural differences proven by SEM inspection. Interaction of particles with the adhesive is different for boards containing BSG compared to those made from wood. Nevertheless, decrease in the mechanical properties was not critical for particleboards produced with 10% BSG which could be potentially classified as a P2 type, this means application in non-load-bearing panel for interior use in dry conditions, with high dimensional stability and stiffness.

scholarly journals Recent Findings in Azaphilone Pigments

2021 ◽  
Vol 7 (7) ◽  
pp. 541
Author(s):  
Lúcia P. S. Pimenta ◽  
Dhionne C. Gomes ◽  
Patrícia G. Cardoso ◽  
Jacqueline A. Takahashi
Keyword(s):  
Water Solubility ◽  
Biological Activities ◽  
Low Cost ◽  
Scale Up ◽  
Structural Diversity ◽  
Downstream Processing ◽  
Global Market ◽  
Yield Improvement ◽  
Potential Applications ◽  
New Compounds

Filamentous fungi are known to biosynthesize an extraordinary range of azaphilones pigments with structural diversity and advantages over vegetal-derived colored natural products such agile and simple cultivation in the lab, acceptance of low-cost substrates, speed yield improvement, and ease of downstream processing. Modern genetic engineering allows industrial production, providing pigments with higher thermostability, water-solubility, and promising bioactivities combined with ecological functions. This review, covering the literature from 2020 onwards, focuses on the state-of-the-art of azaphilone dyes, the global market scenario, new compounds isolated in the period with respective biological activities, and biosynthetic pathways. Furthermore, we discussed the innovations of azaphilone cultivation and extraction techniques, as well as in yield improvement and scale-up. Potential applications in the food, cosmetic, pharmaceutical, and textile industries were also explored.

The Research of Iron Containing Wastes Modification Process of Leninabad Rare Metals Plant

2021 ◽  
Vol 410 ◽  
pp. 778-783
Author(s):  
Pavel V. Matyukhin ◽  
Daler I. Mirzoev
Keyword(s):  
Chemical Composition ◽  
Building Materials ◽  
Raw Material ◽  
Filling Material ◽  
Rare Metals ◽  
X Ray ◽  
Modification Process ◽  
Before And After ◽  
The Republic ◽  
Enrichment Process

The paper presents the results of ferriferous wastes modification process research carried on the basis of JCS “Leninobad rare metals Plant” located in the Republic of Tajikistan. The wastes for the study were taken from the western tailing. The article presents the justification of the chosen wastes as a filling material in the development of new radiation protective composite building materials. The data on the initial ferriferous chemical composition of the tailing wastes and the chemical composition of the material that passed the enrichment process is presented. The study contains microphotos of ferriferous haematite raw material particles surface before and after completing the modifying process. The paper presents and describes the study of X-ray phase analysis diffractograms of enriched iron-containing wastes before and after the modification process. The current research proves that the enrichment ferriferous wastes particles modification process is possible and as a result it can be used as a filling for the development of new kinds of radioprotective composite materials.

INFLUENCE OF LOW-COST BUILDING MATERIALS ON HOUSING PROJECT IN REDUCTION OF HOUSING DEFICIT IN NAIROBI CITY COUNTY, KENYA

2019 ◽  
Vol 4 (2) ◽  
pp. 23-37
Author(s):  
Kamau Maina ◽  
Dr. Samson Nyang’au Paul
Keyword(s):  
Transformational Leadership ◽  
Real Estate ◽  
Building Materials ◽  
Low Cost ◽  
New Technology ◽  
Labour Productivity ◽  
Reliability And Validity ◽  
Value Theory ◽  
Modern Technology ◽  
Primary Data

Purpose: The purpose of the study was to explore the influence of low cost building materials on reduction of housing deficit in Nairobi County, Kenya.Methodology: The study adopted four theories: open innovations theory, the value theory, transformational leadership theory, and institutional theory. Methodologically, the study adopted a descriptive research design, while the population of this study was all the real estate firms registered by Kenya Property Developers Association (KPDA). Census technique was employed to collect data from all 69 real estate firms using questionnaires. Questionnaires were applied to collect primary data, where the researcher trained research assistants to aid the data collection procedure. A pilot-test was conducted as an approach to establishing both the reliability and validity assessments of the questionnaire. Statistical packages for social sciences (SPSS) was used to undertake both descriptive and inferential statistical computations.Results: The findings of the study established that the use of technology enhances the capability and capacity of construction firms to use an array of building materials. The study found that use of modern technology defined skilled labour because most organizations are leveraging technology as a basis of realizing competitive advantage. It also established that real estate firms utilize competent based human resource management firms to hire qualified personnel. In addition, it was evident that personality traits influenced adoption of new technology in the construction of low cost housing, whereas knowledge and attitudes, and skills were significantly attributed to adoption of new technology.Unique contribution to theory, practice and policy: In light of the research findings, the study recommends that organizations should leverage modern technology as a basis of realizing efficiency, effectiveness, and sustainability of projects. The study likewise recommends that organizations should build capacities to enhance labour productivity. In addition, the study recommends that organizations should adopt transformational leadership approaches as a basis of enhancing performance. The study recommends the need to revise the legal framework with a view to ensure that it reflects the changing needs of the project requirements.

scholarly journals Particleboards from Recycled Thermally Modified Wood

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1462
Author(s):  
Ján Iždinský ◽  
Zuzana Vidholdová ◽  
Ladislav Reinprecht
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Brown Rot ◽  
Decay Resistance ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Negative Effect ◽  
Serpula Lacrymans ◽  
Thermally Modified Wood ◽  
Modified Wood

In recent years, the production and consumption of thermally modified wood (TMW) has been increasing. Offcuts and other waste generated during TMWs processing into products, as well as already disposed products based on TMWs can be an input recycled raw material for production of particleboards (PBs). In a laboratory, 16 mm thick 3-layer PBs bonded with urea-formaldehyde (UF) resin were produced at 5.8 MPa, 240 °C and 8 s pressing factor. In PBs, the particles from fresh spruce wood and mixed particles from offcuts of pine, beech, and ash TMWs were combined in weight ratios of 100:0, 80:20, 50:50 and 0:100. Thickness swelling (TS) and water absorption (WA) of PBs decreased with increased portion of TMW particles, i.e., TS after 24 h maximally about 72.3% and WA after 24 h maximally about 64%. However, mechanical properties of PBs worsened proportionally with a higher content of recycled TMW—apparently, the modulus of rupture (MOR) up to 55.5% and internal bond (IB) up to 46.2%, while negative effect of TMW particles on the modulus of elasticity (MOE) was milder. Decay resistance of PBs to the brown-rot fungus Serpula lacrymans (Schumacher ex Fries) S.F.Gray increased if they contained TMW particles, maximally about 45%, while the mould resistance of PBs containing TMW particles improved only in the first days of test. In summary, the recycled TMW particles can improve the decay and water resistance of PBs exposed to higher humidity environment. However, worsening of their mechanical properties could appear, as well.

scholarly journals Mechanical Properties of Commercial Particleboard from Rubberwood (Hevea Brasiliensis) and Recycle Mix-Tropical Wood with Different Board Density

2021 ◽  
Vol 3 (1) ◽  
pp. 41-44
Author(s):  
Nur Wafa Amalina Amali ◽  
Nor Yuziah Mohd Yunus ◽  
Wan Mohd Nazri Wan Abdul Rahman
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Hevea Brasiliensis ◽  
Urea Formaldehyde ◽  
Wood Particle ◽  
Modulus Of Rupture ◽  
Internal Bonding ◽  
Board Density ◽  
Tropical Wood ◽  
Minimum Requirements

In this study, mechanical properties of commercially manufactured hybrid particleboard from mix-tropical wood and rubberwood with four different densities at 25mm thickness have been investigated. The particleboard sample cutting and testing was in accordance to EN312:2013. The density of particleboard is identified with interval of 10kg/m3 for different densities which include 660kg/m3, 670kg/m3, 680kg/m3 and 690kg/m3. Particleboards were made with the ratio of 40:60 for mix-tropical wood particle and rubberwood particle respectively. The particleboards were prepared with urea formaldehyde (UF) with E1 formulation with addition of wax and hardener.  Increment of 10kg/m3 density for each particleboard led to increase in internal bonding (IB), bending testing include modulus of rupture (MOR) and modulus of elasticity (MOE), surface soundness (SS) and screw edge (SE) withdrawal. It was found that with board increment of 10kg/m3, the improvement was not statically significant except that for MOR. All panels met the minimum requirements of standard.

scholarly journals Green Synthesis of Silver Nanoparticles Using Raw Fruit Extract of Mimusops elengi and their Antimicrobial Study

2020 ◽  
Vol 11 (3) ◽  
pp. 10040-10051
Keyword(s):  
Green Synthesis ◽  
Colloidal Stability ◽  
Low Cost ◽  
Antimicrobial Activities ◽  
Health Food ◽  
Ag Nps ◽  
Fruit Extract ◽  
Silver Nps ◽  
Mimusops Elengi ◽  
Bacteria And Fungi

These days, nanoparticles are being considered as nano-antibiotics because of their execution of antimicrobial activities towards a broad range of microbes. Nanoparticles are used in industrial products, health, food, space, and cosmetics;thus, researchers need for a green, ecofriendly, and low-cost approach to synthesize it. Green synthesis is such an approach of synthesizing NPs using microorganisms and plants, which is free of additional impurities. We used Mimusops elengi Linn. raw fruit extract in water to reduce the silver nitrate salt to produce silver NPs. The samples were characterized using various instrumental techniques. Broadband known as Surface Plasmon Resonance found near 450 nm in the absorption spectrum shows the formation of Ag NPs. NPs with average hydrodynamic diameters in the ranges 20-300 nm were detected from DLS study having negative zeta potential value (varies between - 25.8 to 15.8 mV), which suggests that as NPs surface is charged, it provides colloidal stability to the NPs in a liquid medium. FTIR study reveals that an increase in the intensity of some of the vibrational band with NP-content is due to the adsorption of some molecules on the surface of NPs. XRD pattern shows that NPs have an fcc structure. Samples were tested to have capabilities to kill both bacteria and fungi.

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