Wood Adhesives Based on Natural Resources: A Critical Review: Part IV. Special Topics

2021 ◽  
Vol 9 (2) ◽  
pp. 189-268
Author(s):  
Manfred Dunky
Keyword(s):  
Natural Resources ◽  
Phenol Formaldehyde ◽  
Direct Synthesis ◽  
Cellulose Nanofibrils ◽  
Raw Material ◽  
Poly Lactic Acid ◽  
Natural Polymers ◽  
Wood Adhesives ◽  
Cashew Nut ◽  
Wood Bonding

Various naturally-based chemicals can be used directly as wood adhesives or are precursors for the synthesis of adhesive resins. Liquefaction and pyrolysis of wood yield various smaller chemicals derived from the different wood components, which then are used in the preparation of adhesives by replacing mainly phenol as raw material. The possible replacement of formaldehyde in aminoplastic and phenolic resins would solve the question of the subsequent formaldehyde emission.<br/> The multiple unsaturations of the triglycerides in vegetable oils enable polymerization for the direct synthesis of thermosets, as well as bases for polyfunctionalization and crosslinking.<br/> Natural polymers, such as poly(lactic acid)s (PLAs), natural rubber, or poly(hyhydroxyalkanoate)s (PHAs) are thermoplastics and can be used for various special applications in wood bonding, in case they can also be crosslinked. For other thermoplastic wood adhesives, such as PUR or PA, chemicals based on natural resources can at least replace a part or even all synthetic raw materials (monomers); these monomers derive from targeted decomposition of the wood material in biorefineries.<br/> Cellulose nanofibrils (CNFs) can be used as as sole adhesives or as components of adhesives. Hydrogen bonding has a key function in binder applications related to adhesion between cellulose nanoparticles and other materials. CNFs are able to establish strong bonding between wood particles/fibres through flexible and strong films by a simple drying process.<br/> Cashew nut shell liquid (CNSL) is a by-product of the cashew nut processing with cardanol (CD) as main component. CD-formaldehyde resins show improved flexibility compared to phenol-formaldehyde (PF) resins; CD can replace up to 40% of the phenol.

Facile preparation of nanofiller-paper using mixed office paper without deinking

TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Cellulose Nanofibrils ◽  
Ash Content ◽  
Raw Material ◽  
Mechanical Grinding ◽  
Microscope Imaging ◽  
Facile Preparation ◽  
Electron Microscope Imaging ◽  
Thermal Stability Of ◽  
Scanning Electron ◽  
Office Paper

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.

scholarly journals Bio-Based Alternatives to Phenol and Formaldehyde for the Production of Resins

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim
Keyword(s):  
Raw Materials ◽  
Phenol Formaldehyde ◽  
Raw Material ◽  
Wood Industry ◽  
Suitable Material ◽  
The Past ◽  
Wide Range ◽  
Recent Developments ◽  
Sustainable Materials ◽  
Materials Used

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.

scholarly journals Effects of Water and Chemical Solutions Ageing on the Physical, Mechanical, Thermal and Flammability Properties of Natural Fibre-Reinforced Thermoplastic Composites

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4581
Author(s):  
Baljinder K. Kandola ◽  
S. Ilker Mistik ◽  
Wiwat Pornwannachai ◽  
A. Richard Horrocks
Keyword(s):  
Salt Water ◽  
Flexural Modulus ◽  
Moisture Sorption ◽  
Natural Fibre ◽  
Thermoplastic Composites ◽  
Wool Fibre ◽  
Poly Lactic Acid ◽  
Natural Polymers ◽  
Chemical Solutions ◽  
Pp Composites

Biocomposites comprising a combination of natural fibres and bio-based polymers are good alternatives to those produced from synthetic components in terms of sustainability and environmental issues. However, it is well known that water or aqueous chemical solutions affect natural polymers/fibres more than the respective synthetic components. In this study the effects of water, salt water, acidic and alkali solutions ageing on water uptake, mechanical properties and flammability of natural fibre-reinforced polypropylene (PP) and poly(lactic acid) (PLA) composites were compared. Jute, sisal and wool fibre- reinforced PP and PLA composites were prepared using a novel, patented nonwoven technology followed by the hot press method. The prepared composites were aged in water and chemical solutions for up to 3 week periods. Water absorption, flexural properties and the thermal and flammability performances of the composites were investigated before and after ageing each process. The effect of post-ageing drying on the retention of mechanical and flammability properties has also been studied. A linear relationship between irreversible flexural modulus reduction and water adsorption/desorption was observed. The aqueous chemical solutions caused further but minor effects in terms of moisture sorption and flexural modulus changes. PLA composites were affected more than the respective PP composites, because of their hydrolytic sensitivity. From thermal analytical results, these changes in PP composites could be attributed to ageing effects on fibres, whereas in PLA composite changes related to both those of fibres present and of the polymer. Ageing however, had no adverse effect on the flammability of the composites.

Preparation and characterization of tannin-based adhesives reinforced with cellulose nanofibrils for wood bonding

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Uasmim Lira Zidanes ◽  
Matheus Cordazzo Dias ◽  
Mário Sérgio Lorenço ◽  
Elesandra da Silva Araujo ◽  
Maryella Júnnia Ferreira e Silva ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Glue Line ◽  
Mechanical Resistance ◽  
Thermogravimetric Analyses ◽  
Humidity Resistance ◽  
Wood Bonding ◽  
Toona Ciliata ◽  
Solids Content ◽  
The One

AbstractAdhesives based on vegetable tannins are already a reality in the market. However, their use is still limited due to their low mechanical resistance and weak humidity resistance. Cellulose nanofibrils (CNFs) are being used as reinforcing materials in various composites, resulting in an improvement of mechanical proprieties in general. The objective of this work was to evaluate the incorporation of CNFs in adhesives made of tannins obtained from the Angico tree (Anadenanthera peregrine). Concentrations of nanofibrils at 1, 5, and 10% were added to the adhesives on a dry basis. Tests of viscosity, pH, solids content, and gel time were performed to determine the physical proprieties of the adhesives. The Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Raman spectra measurements were also determined to understand the interaction between tannins and CNFs. Thermogravimetric analyses (TGA) were carried out to determine the thermal resistance of the composite. The FTIR and Raman characterization identified some differences in the peaks in the chemical composition of the adhesives with different percentages of CNFs. The adhesives showed no different decomposition in the thermogravimetric analyses. The shear strength in the glue line of the adhesive with 5% of CNFs in Toona ciliata woods was determined. Among all the adhesives analyzed, the one with 5% of CNFs produced an improvement in the mechanical resistance and humidity resistance on the glue line.

scholarly journals Odor and Constituent Odorants of HDPE–Lignin Blends of Different Lignin Origin

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 206
Author(s):  
Bianca Lok ◽  
Gunnar Mueller ◽  
Johannes Ganster ◽  
Jens Erdmann ◽  
Andrea Buettner ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Raw Materials ◽  
Mineral Oil ◽  
Raw Material ◽  
Systematic Evaluation ◽  
Natural Polymers ◽  
Kraft Process ◽  
Global Demand ◽  
Reduction Strategies ◽  
Soda Lignin

The still-rising global demand for plastics warrants the substitution of non-renewable mineral oil-based resources with natural products as a decisive step towards sustainability. Lignin is one of the most abundant natural polymers and represents an ideal but hitherto highly underutilized raw material to replace petroleum-based resources. In particular, the use of lignin composites, especially polyolefin–lignin blends, is currently on the rise. In addition to specific mechanical property requirements, a challenge of implementing these alternative polymers is their heavy odor load. This is especially relevant for lignin, which exhibits an intrinsic odor that limits its use as an ingredient in blends intended for high quality applications. The present study addressed this issue by undertaking a systematic evaluation of the odor properties and constituent odorants of commercially available lignins and related high-density polyethylene (HDPE) blends. The potent odors of the investigated samples could be attributed to the presence of 71 individual odorous constituents that originated primarily from the structurally complex lignin. The majority of them was assignable to six main substance classes: carboxylic acids, aldehydes, phenols, furan compounds, alkylated 2-cyclopenten-1-ones, and sulfur compounds. The odors were strongly related to both the lignin raw materials and the different processes of their extraction, while the production of the blends had a lower but also significant influence. Especially the investigated soda lignin with hay- and honey-like odors was highly different in its odorant composition compared to lignins resulting from the sulfurous kraft process predominantly characterized by smoky and burnt odors. These observations highlight the importance of sufficient purification of the lignin raw material and the need for odor abatement procedures during the compounding process. The molecular elucidation of the odorants causing the strong odor represents an important procedure to develop odor reduction strategies.

scholarly journals STUDI ETNOBOTANI SUKU DAYAK RIBUN DALAM PEMANFAATAN TUMBUHAN BERNILAI SENI DI DESA GUNAM KECAMATAN PARINDU KABUPATEN SANGGAU

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Arit Nggadas ◽  
M Idham ◽  
Lolyta Sisillia
Keyword(s):  
Data Collection ◽  
Natural Resources ◽  
Raw Materials ◽  
Musical Instruments ◽  
Raw Material ◽  
Survey Method ◽  
Snowball Sampling ◽  
Art Forms ◽  
Depth Interviews ◽  
Number Of Plant Species

The Dayak Ribun Tribe Society has natural resources that can be developed as a source of community income. Interaction with nature still exists today so there is a need for research on the types of plants that are used, the art forms that are made and the parts of the plants that are used by the Dayak Ribun Tribe of Gunam Village, Parindu District, Sanggau District as art crafts. The method used in this study is a survey method with interview techniques for taking respondents to snowball sampling. Retrieval of data or information is carried out directly by researchers on selected respondents, prospective respondents are determined by respondents who have been interviewed beforehand and continue to the next respondent. Respondents were obtained as many as 32 people. Data collection is done by observation, in-depth interviews, and documentation using a camera. The number of plant species used in Gunam Village as raw material for crafts and raw materials for musical instruments as many as 14 species from 9 families includes Areaceae, Gleicheniaceae, Poaceae, Thymelaeaceae, Apocynaceae, Dipterocarpaceae, Simaroubaceae, Fagaceae and Moraceae. The part of the plant that was used by the community in Gunam Village was found as many as 9 types of stems, 2 types of leaves, 2 types of seeds, 1 root, 1 type of fruit and 1 bark. There were two types of plants that were used by more than one plant organs namely Kemenyan or Aquilaria sp and keraci or Lithocarpus sp. Art forms that are used in the form of crafts and musical instruments. Crafts include key chains, clothes racks, chairs, rings, bracelets, takin, mats, hats, necklaces, drinking glasses, plates, clothes, bags, ropes, while musical instruments are sapeKeywords: Dayak Ribun, Ethnobotany, Utilization of plant

scholarly journals Uso da argila no processo produtivo da cerâmica vermelha: Um estudo de caso no município de Paudalho, Pernambuco

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Y. M. Paz ◽  
R. M. Holanda ◽  
S. G. El-Deir
Keyword(s):  
Natural Resources ◽  
Production Process ◽  
High Availability ◽  
Raw Material ◽  
Renewable Natural Resources ◽  
Ceramic Blocks ◽  
Renewable Natural Resource ◽  
The City ◽  
Red Ceramics

As frações granulométricas do solo são consideradas recursos naturais não renováveis, devido a escala de tempo necessária para sua formação. A argila possui elevada disponibilidade na natureza, e por isso seu uso ainda é indiscriminado. É a matéria-prima principal para as indústrias de cerâmica vermelha pulverizadas em todo o território brasileiro. O objetivo do trabalho foi realizar uma discussão acerca do recurso natural não renovável argila e seu uso no processo produtivo da Indústria de cerâmica vermelha. Este foi desenvolvido através de pesquisa bibliográfica, e estudo de caso com realização de visitas técnicas a uma indústria de cerâmica vermelha localizada no município de Paudalho no estado de Pernambuco. No ano de 2013 a Indústria X adquiriu para estoque e consumo 70.161 toneladas, para uma produção de 35.806.268 blocos de cerâmica. De todo o quantitativo produzido houve uma perda de 7,5%, que reflete em 4.768 toneladas de argila e num prejuízo aproximado de R$ 845.835,52. Através do trabalho realizado percebe-se que há uma necessidade de planejamento da exploração e uso dos recursos naturais não renováveis, pois estes podem se tornar escassos e inviabilizar determinados processos produtivos. Isso pode acarretar em conflitos sociais e econômicos, pela valoração dos recursos e diminuição de disponibilidade para uso, ocasionando redução dos lucros por parte dos empresários e por consequência diminuição na oferta de empregos.Use of clay in the production process of the Red Ceramics: A case study in the city of Paudalho, Pernambuco Abstract: The fractions of soil are considered non-renewable natural resources, because the time scale required for its formation. Clay has high availability in nature, and therefore its use is still indiscriminate. It is the main raw material for the manufacture of red ceramic sprayed throughout the Brazilian territory. The objective was to conduct a discussion of non-renewable natural resource clay and its use in industry's production process of red ceramic. It was developed through literature review and case study of technical a red ceramic industry in the municipality of Paudalho in Pernambuco state visits. In 2013 the X Industry acquired for stock and consumption 70,161 tons, for a production of 35,806,268 ceramic blocks. The entire quantity produced there was a loss of 7.5%, which reflects in 4,768 tons of clay and an approximate loss of R $ 845,835.52. Through work is noticed that there is a need for planning of exploration and use of non-renewable natural resources, as they may become scarce and derail certain production processes. This can lead to social and economic conflicts, the valuation of resources and reduced availability for use, resulting in lower profits for entrepreneurs and consequently decrease in the supply of jobs.

scholarly journals Who is Responsible for Instability in the Democratic Republic of Congo?

2014 ◽  
pp. 29-36
Author(s):  
G. M. Sidorova
Keyword(s):  
Natural Resources ◽  
Democratic Republic ◽  
Central Government ◽  
Democratic Republic Of Congo ◽  
Raw Material ◽  
Political Crisis ◽  
Armed Groups ◽  
Long Time ◽  
The Usa ◽  
Republic Of The Congo

The research focuses on the problem of military-political instability in the Democratic Republic of the Congo experiencing continued armed conflict for a long time. Dozens of illegal armed groups both Congolese and foreign origin continue to destabilize situation in the eastern part of the country causing humanitarian disasters. Due to governmental weakness, economic backwardness, chronical lack of finance resources, interethnic conflicts, all-round and widely spread corruption of the authorities, the Congolese government at the moment is not able to overcome scores of problems including the problem of security. Assistanceprovided to the DRC by itspartnerssuch as, first of all, the former metropolitan country Belgium, as well as the USA, Great Britain, the Europe Union and China works only in favourof these country-donors. They are attracted by rich Congolese natural resources which the DRC remaining one of the poorest countries in the world cannot turn to advantage to the full extent because of its economic backwardness. In exchange for so-calleddevelopment programmes, expensive strategic raw material (such as coltan, wolfram, casseterit, cooper, gold, niobium, and other) is being extracted and exported from the country, in addition, often on the inequivalent basis. This is taking place for the reason that numerous mines and open-cast mines are being controlled by different illegal armed groups and not by the central government. Therefore, it turns out that in the context of a military-political crisis, for so-called partners it is more beneficial to pursue their own interests. Furthermore, western ideologists arouse "separatism-oriented" theories similar to "balkanization", in other words, a breakdown of this giant country into several independent states. The Congolese are tremulous to this issue, they try to counter such approachs and defend the territorial integrity of the DRC. However, it is not an easy task. The impediment is unsettled relations with neighbouring countries - Rwanda, Uganda and Burundi which for tens of years exploit illegally natural resources of the DRC and try to lay hold of frontier Congolese territories.

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