scholarly journals Suitability and Modification of Different Renewable Materials as Feedstock for Sustainable Flame Retardants

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5122
Author(s):  
Stefan Gebke ◽  
Katrin Thümmler ◽  
Rodolphe Sonnier ◽  
Sören Tech ◽  
Andre Wagenführ ◽  
...  

Due to their chemical structure, conventional flame retardants are often toxic, barely biodegradable and consequently neither healthy nor environmentally friendly. Their use is therefore increasingly limited by regulations. For this reason, research on innovative flame retardants based on sustainable materials is the main focus of this work. Wheat starch, wheat protein, xylan and tannin were modified with phosphate salts in molten urea. The functionalization leads to the incorporation of phosphates (up to 48 wt.%) and nitrogen (up to 22 wt.%). The derivatives were applied on wood fibers and tested as flame retardants. The results indicate that these modified biopolymers can provide the same flame-retardant performances as commercial compounds currently used in the wood fiber industry. Besides, the flame retardancy smoldering effects may also be reduced compared to unmodified wood fibers depending on the used biopolymer. These results show that different biopolymers modified in phosphate/urea systems are a serious alternative to conventional flame retardants.

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 335 ◽  
Author(s):  
Stefan Gebke ◽  
Katrin Thümmler ◽  
Rodolphe Sonnier ◽  
Sören Tech ◽  
André Wagenführ ◽  
...  

Biopolymer-based flame retardants (FR) are a promising approach to ensure adequate protection against fire while minimizing health and environmental risks. Only a few, however, are suitable for industrial purposes because of their poor flame retardancy, complex synthesis pathway, expensive cleaning procedures, and inappropriate application properties. In the present work, wheat starch was modified using a common phosphate/urea reaction system and tested as flame retardant additive for wood fibers. The results indicate that starch derivatives from phosphate/urea systems can reach fire protection efficiencies similar to those of commercial flame retardants currently used in the wood fiber industry. The functionalization leads to the incorporation of fire protective phosphates (up to 38 wt.%) and nitrogen groups (up to 8.3 wt.%). The lowest levels of burning in fire tests were measured with soluble additives at a phosphate content of 3.5 wt.%. Smoldering effects could be significantly reduced compared to unmodified wood fibers. The industrial processing of a starch-based flame retardant on wood insulating materials exhibits the fundamental applicability of flame retardants. These results demonstrate that starch modified from phosphate/urea-systems is a serious alternative to traditional flame retardants.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2747
Author(s):  
Erfan Oliaei ◽  
Tom Lindström ◽  
Lars A. Berglund

Low-porosity materials based on hot-pressed wood fibers or nanocellulose fibrils (no polymer matrix) represent a new concept for eco-friendly materials with interesting mechanical properties. For the replacement of fossil-based materials, physical properties of wood fiber materials need to be improved. In addition, the carbon footprint and cumulative energy required to produce the material also needs to be reduced compared with fossil-based composites, e.g., glass fiber composites. Lignin-containing fibers and nanofibers are of high yield and special interest for development of more sustainable materials technologies. The present mini-review provides a short analysis of the potential. Different extraction routes of lignin-containing wood fibers are discussed, different processing methods, and the properties of resulting fiber materials. Comparisons are made with analogous lignin-containing nanofiber materials, where mechanical properties and eco-indicators are emphasized. Higher lignin content may promote eco-friendly attributes and improve interfiber or interfibril bonding in fiber materials, for improved mechanical performance.


2006 ◽  
Vol 102 (5) ◽  
pp. 4759-4763 ◽  
Author(s):  
Alinaghi Karimi ◽  
Saleh Nazari ◽  
Ismaeil Ghasemi ◽  
Mehdi Tajvidi ◽  
Ghanbar Ebrahimi

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2648 ◽  
Author(s):  
Kuruma Malkappa ◽  
Jayita Bandyopadhyay ◽  
Suprakas Ray

Polylactide (PLA) is one of the most widely used organic bio-degradable polymers. However, it has poor flame retardancy characteristics. To address this disadvantage, we performed melt-blending of PLA with intumescent flame retardants (IFRs; melamine phosphate and pentaerythritol) in the presence of organically modified montmorillonite (OMMT), which resulted in nanobiocomposites with excellent intumescent char formation and improved flame retardant characteristics. Triphenyl benzyl phosphonium (OMMT-1)- and tributyl hexadecyl phosphonium (OMMT-2)-modified MMTs were used in this study. Thermogravimetric analysis in combination with Fourier transform infrared spectroscopy showed that these nanocomposites release a smaller amount of toxic gases during thermal degradation than unmodified PLA. Melt-rheological behaviors supported the conclusions drawn from the cone calorimeter data and char structure of the various nanobiocomposites. Moreover, the characteristic of the surfactant used for the modification of MMT played a crucial role in controlling the fire properties of the composites. For example, the nanocomposite containing 5 wt.% OMMT-1 showed significantly improved fire properties with a 47% and 68% decrease in peak heat and total heat release rates, respectively, as compared with those of unmodified PLA. In summary, melt-blending of PLA, IFR, and OMMT has potential in the development of high-performance PLA-based sustainable materials.


Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1038
Author(s):  
Muhammad Maqsood ◽  
Gunnar Seide

To improve sustainability of polymers and to reduce carbon footprint, polymers from renewable resources are given significant attention due to the developing concern over environmental protection. The renewable materials are progressively used in many technical applications instead of short-term-use products. However, among other applications, the flame retardancy of such polymers needs to be improved for technical applications due to potential fire risk and their involvement in our daily life. To overcome this potential risk, various flame retardants (FRs) compounds based on conventional and non-conventional approaches such as inorganic FRs, nitrogen-based FRs, halogenated FRs and nanofillers were synthesized. However, most of the conventional FRs are non-biodegradable and if disposed in the landfill, microorganisms in the soil or water cannot degrade them. Hence, they remain in the environment for long time and may find their way not only in the food chain but can also easily attach to any airborne particle and can travel distances and may end up in freshwater, food products, ecosystems, or even can be inhaled if they are present in the air. Furthermore, it is not a good choice to use non-biodegradable FRs in biodegradable polymers such as polylactic acid (PLA). Therefore, the goal of this review paper is to promote the use of biodegradable and bio-based compounds for flame retardants used in polymeric materials.


BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3339-3351 ◽  
Author(s):  
Baowen Wang ◽  
Zhihui Li ◽  
Xinglai Qi ◽  
Nairong Chen ◽  
Qinzhi Zeng ◽  
...  

Wood fibers were prepared as core materials for a vacuum insulation panel (VIP) via a dry molding process. The morphology of the wood fibers and the microstructure, pore structure, transmittance, and thermal conductivity of the wood fiber VIP were tested. The results showed that the wood fibers had excellent thermal insulation properties and formed a porous structure by interweaving with one another. The optimum bulk density that led to a low-cost and highly thermally efficient wood fiber VIP was 180 kg/m3 to 200 kg/m3. The bulk density of the wood fiber VIP was 200 kg/m3, with a high porosity of 78%, a fine pore size of 112.8 μm, and a total pore volume of 7.0 cm3·g-1. The initial total thermal conductivity of the wood fiber VIP was 9.4 mW/(m·K) at 25 °C. The thermal conductivity of the VIP increased with increasing ambient temperature. These results were relatively good compared to the thermal insulation performance of current biomass VIPs, so the use of wood fiber as a VIP core material has broad application prospects.


2021 ◽  
Vol 14 ◽  
Author(s):  
Menandro N. Acda

Background: High-density fiberboards (HDF) are widely used as a substitute for solid wood in furniture, cabinet, construction materials, etc. Wood fibers are often used in the production of HDF but the use of renewable materials has gained worldwide interest brought about by global pressure to pursue sustainable development. An abundant source of renewable fibers that can be used to produce HDF is keratin from waste chicken feathers. The goal of the study is to investigate the use of keratin fibers in combination with wood fibers to produce HDF. No or limited studies have been conducted in this area and if successful, it could offer an alternative utilization for the billions of kilograms of waste feather produced by the poultry industry. HDF is a high volume feather utilization that can reduce pollution and help solve solid waste disposal problems in many countries. Methods: A series of dry-formed HDFs containing varying ratios of wood and keratin fibers bonded by polyurethane resin were produced. The physical and mechanical properties of the HDFs were determined. Results : The properties of the HDFs were affected by varying ratios of wood particles and keratin fibers. Dimensional stability as indicated by low levels of thickness swelling (<4.6%) and water absorption (<10%) was observed. Internal bond (2.47 MPa), MOE (5.8 GPa) and MOR (45 MPa) values were higher or comparable to those reported in the literature. Conclusion: HDF formed using a combination of wood and keratin fibers bonded together by polyurethane resin to as much as 50% keratin fibers were dimensionally stable with stiffness and strength above the minimum requirements for general use HDF as prescribed by EN 622-5.


2017 ◽  
Vol 45 (2) ◽  
pp. 442-445
Author(s):  
Federica LARCHER ◽  
Luca BATTISTI ◽  
Walter GAINO ◽  
Marco DEVECCHI

The economic importance of the bamboo cultivation in Asia is well known, but the recent rise of interest in Europe required more deep studies on growing techniques. Among the bamboo species, the Phyllostachys pubescens (Carrière) J. Houz. is appreciated for its multiple uses: landscaping, timber and shoots production. In order to identify the best and sustainable combination of substrates and fertilization regimes, a nursery experimental trial was performed in 2016. Eight treatments (four substrates and two fertilization regimes) with 256 young plantlets divided into four randomized blocks were evaluated. The substrates used were: 40% peat, 40% coconut fibers, 20% pumice (standard substrate, S1); 30% peat, 40% coconut fibers, 10% rice husk, 20% pumice (S2); 30% peat, 40% coconut fibers, 20% rice husk, 10% pumice (S3); 30% peat, 40% coconut fibers, 20% wood fibers, 10% pumice (S4). The two fertilization regimes were: 1.6 g l-1 (A) and 0.8 g l-1 (B) NPK (16-11-10) Osmocote Exact®. All substrates were supplemented with a fungal inoculum (2.5 g l-1) and corrected with 2.5 × 10-3 g l-1 of CaCO3. The number of culms and leaves and the SPAD values of six plants of each blocks were monthly measured. Fresh and dry weights, before and after cultivation was recorded. Data were statistically analyzed. Results showed that rice husk should be used only in low percentage, but wood fiber can be more suitable for bamboo cultivation. The combination of alternative materials and low fertilization regimes (S1_B and S4_B) should be the key for a more sustainable cultivation for potted Phyllostachys pubescens in Europe.


1998 ◽  
Vol 4 (S2) ◽  
pp. 838-839
Author(s):  
A. Egan ◽  
S. Shaler

Single fiber fracture is important in understanding the fundamental failure mechanisms in wood/polymer composite products such as medium density fiberboard (MDF). The mechanical properties and fracture behavior of individual wood fibers has only recently been observable using a combination of environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy and digital image correlation (DIC). Previous work has shown that specific areas on the fiber such as microcompressions and pits acted as crack nucelators and induce a brash fracture across the surface of the fiber. Given the development of these procedures it is now possible to observe and measure the mechanical properties and fracture characteristics of the wood fiber/ polymer composite fibers.Individual black spruce wood fibers were coated with diphenylmethane 4-4'diisocyanate resin containing Hostasol Red GG. The addition of the Hostasol Red flurochrome provided the option of quantifying resin coverage by fluorescence microscopy.


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