Smoke Production Research Articles

Influence of hot-smoking on the stability of fresh and frozen-thawed deep-skinned Atlantic mackerel fillets during cold storage.

Atlantic mackerel (Scomber scombrus) caught during the summer months in Icelandic waters after intensive feeding is rich in lipids and, thus, sensitive to lipid degradation. Recent studies have led to improved cooling and handling on board, ensuring high-quality raw material. However, studies on the development of high-quality products for human consumption are lacking. The study aimed to investigate the effects of hot-smoking on the physicochemical, microbial, and sensory quality of deep-skinned Atlantic mackerel fillets during chilled storage (1 ± 0.6°C). In addition, the quality of smoked mackerel from frozen-thawed fillets (9 months at -25 ± 1.8°C) was compared to that of fresh-smoked fillets to evaluate the possibility of the industry being able to provide smoked fillets throughout the year, despite the short fishing season. Brining and hot-smoking reduced total viable counts and inactivated Listeria monocytogenes. Hot-smoking positively affected the sensory attributes of the fillets and sensory quality was largely maintained for at least 21 days of chilled storage. Although slightly lower sensory and texture scores were obtained for frozen-thawed smoked fillets, they remained within acceptable limits throughout the period of cold storage. The shelf-life of smoked Atlantic mackerel deep-skinned fillets stored at 1°C is, therefore, assessed to be at least 21 days. Well-fed Atlantic mackerel is suitable for developing high-quality and stable smoked fillet products from both fresh and frozen-thawed raw materials.

Bismuth oxyiodide nanorods towards improvements in fire safety and mechanical properties of natural rubber

Fire safety represents an enduring challenge in the realm of polymer-based nanocomposites, significantly limiting their application. The utilization of bismuth oxyiodide in flame retardant applications offers advantages such as increased surface area for improved interaction with combustible materials, the formation of a uniform flame retardant layer at the interface, and enhanced thermal stability. Hence, this work explored a facile strategy to synthesize bismuth oxyiodide nanorods by hydrothermal method combined with ball milling in anticipation of constructing an efficient flame retardant system. The bismuth oxyiodide nanorods dispersed relatively uniformly in the natural rubber matrix and endowed natural rubber nanocomposites with enhanced mechanical properties and fire-safety. The resultant natural rubber nanocomposite containing 5 wt% of bismuth oxyiodide showed a 36 % improvement in the tensile strength and a 39 % increase in the tear strength compared to those of the neat natural rubber. Cone calorimeter tests revealed that the introduction of 5 wt% bismuth oxyiodide to natural rubber matrix remarkably reduced the peak of heat release rate and peak smoke production release by 22 % and 25 %, respectively. A rational flame retardant mode of action for bismuth oxyiodide nanorods was proposed based on the analysis of pyrolysis fragments and char residues. Hence, this work provides a green and feasible method to prepare bismuth oxyiodide nanorods for flame retardant natural rubber products.

Improving Processability and Mechanical Properties of Epoxy Resins with Bio‐Based Flame Retardants

AbstractIntegrating flame retardant additives into epoxy resins is an essential strategy for improving their fire resistance. However, introducing flame retardant groups often compromises the processability and mechanical integrity of the resins. In this research, we synthesized a novel, bio‐based flame retardant, referred to as DPN, using naringenin and chlorodiphenylphosphine as precursors via a straightforward single‐step process. The addition of DPN dramatically decreased the viscosity of Hydantoin Epoxy Resin, from 7468 mPa·s to 1285 mPa·s. Furthermore, when cured with 4,4‐diaminodiphenylmethane (DDM), the composite containing 5 equivalents of DPN (DPN‐5) exhibited a remarkable improvement in mechanical strength, reaching 190 MPa, significantly outperforming the pure thermoset (DPN‐0: 104 MPa), while preserving high transparency. Combustion tests further confirmed that DPN significantly boosts the flame resistance of the thermoset, with DPN‐5 achieving a Limiting Oxygen Index (LOI) of 37% and securing a UL‐94 V‐0 rating. Cone calorimetry analysis showed that DPN‐5 effectively reduced heat and smoke production during combustion, achieving a 13.4% reduction in Peak Heat Release Rate and a 28.2% decrease in Total Heat Release compared to DPN‐0. This study underscores the potential of multifunctional bio‐based flame retardants derived from renewable resources in advancing the development of high‐performance materials.This article is protected by copyright. All rights reserved.

Recyclable porous core-shell Mn-Co-O flame retardant for improving flame retardancy and smoke suppression of epoxy resin

The development of metal oxide flame retardants that are easy to synthesize, efficient, and recyclable would be more beneficial to circular economy. In this work, a porous core-shell Mn3CoOx was developed to efficiently reduce heat, smoke as well as hazardous gas during the combustion of epoxy resin (EP). Compared with pure EP, the peak heat release rate (pHRR), total heat release (THR), peak smoke production rate (pSPR), total smoke production (TSP), peak CO production rate (pCOPR), and peak CO2 production rate (pCO2PR) of EP/Mn3CoOx are reduced by 47.5 %, 21.5 %, 34.6 %, 17.6 %, 58.6 %, and 55.4 %, respectively. It has been shown that Mn3CoOx not only catalyzes the formation of high-quality char layer but also effectively catalyzes the conversion of hazardous gas products into CO2. Recovery experiments of Mn3CoOx filler in EP composites show that the recovery of Mn3CoOx can reach 90.0 %. This work provides insights into the design of efficient metal oxide flame retardants and ideas for the development of recycled flame retardants.

Enhancing flame retardancy, anti‐impact, and corrosive resistance of TPU nanocomposites using surface decoration of α‐ZrP

AbstractThe development of polyurethane composites with significant flame retardancy and corrosion resistance for widening its practical application is a great importance. In this study, supramolecular wrapped α‐ZrP (MCP@ZrP) was prepared via self‐assembly of melamine, cobalt ions (Co2+) and phytic acid (PA) on the surfaces of α‐zirconium phosphate (α‐ZrP). It was found that both compatibility and dispersion of α‐ZrP sheets in thermoplastic polyurethane (TPU) matrices were improved with the incorporation of organic supramolecular components in TPU/MCP@ZrP nanocomposites. Moreover, their fire‐retardant characteristic was significantly enhanced, along with effective suppression of smoke and toxic gas emission. By adding 5 wt% MCP@ZrP, peak heat release rate, total heat release, total smoke production, and total CO production of such nanocomposites were reduced by 35.66%, 18.01%, 15.52%, and 41.42%, respectively. The generation of a continuous and dense char layer benefited from well‐dispersed MCP@ZrP nanohybrids, which resulted in tortuous effect to impede heat diffusion and prevent the evaporation of volatile gasses. By means of the barrier effect of ZrP, TPU/MCP@ZrP composite films also showed improved anticorrosion performance. Effective interfacial adhesion, achieved by combining MCP supermolecules and α‐ZrP sheets, offers a viable approach to improve protective properties of TPU nanocomposites.Highlights Supramolecular‐wrapped α‐ZrP was prepared via self‐assembly strategy. MCP@ZrP showed good dispersion and interface adhesion within TPU matrices. MCP@ZrP enhanced the flame retardancy and mechanical performance of TPU. MCP@ZrP preventing smoke and toxic gas evaporation.

Intramolecular cooperation and biphasic flame retardant mode of action: Effectiveness of hexa(1,2,4-triazol-3-ylamine) cyclotriphosphazene in epoxy resin

The substitutional structure of cyclotriphosphazene derivatives significantly influences their flame-retardant effectiveness. A cyclotriphosphazene derivative with triazole group, referred to as hexa(1,2,4-triazol-3-ylamine) cyclotriphosphazene (HATA), was utilized to improve the flame retardancy of epoxy resin (EP). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were employed to characterize the thermal properties of EP/HATA thermosets. HATA facilitated the curing of EP due to its triazole and secondary amine structure. EP/HATA thermosets exhibited improved char-forming ability and storage modulus, attributed to the rigid cyclophosphonitrile structure of HATA. As a result of incorporating 5% HATA with 0.73 wt% phosphorus, EP passed UL-94 V-0 level. Subsequent analysis using a cone calorimeter revealed obvious reductions in the peak heat release rate, fire growth rate, and total smoke production of EP with the addition of HATA. Simultaneously, there was a significant enhancement in the char yield of EP during combustion, indicating notable improvements in fire safety. Additional investigations, including X-ray photoelectron spectroscopy, scanning electron microscopy, TG-FTIR, and pyrolysis gas chromatography/mass spectrometry, were employed to analyze the char residue and gaseous volatiles. HATA promoted the formation of a dense, continuous, and intumescent char layer containing cyclophosphonitrile structure in EP. Moreover, the decomposition of HATA released a notable quantity of nitrogen-containing volatiles, effectively mitigating flammable gases originating from the EP matrix in gaseous phase. A biphasic flame-retardant mode of action was proposed, underscoring cooperative flame-retardant effects arising from the interaction between triazole substituents and cyclophosphonitrile structure in HATA molecular for EP.

Synergistic enhancement of toughness and flame retardation for cyanate ester composites through hyperbranched polyborosiloxane

AbstractExcellent flame resistance is supposed to be taken into consideration for electronic packaging materials due to the spontaneous combustion of short circuits, except for good mechanical and dielectric properties. Herein, a hyperbranched polyborosiloxane (HPSiB) flame retardant was synthesized via a simple one‐pot transesterification as a multifunctional additive for cyanate ester (CE) resin. The HPSiB with many active terminals features good compatibility with the resin matrix, while catalyzing the curing reaction that conducts at a lower temperature. With as little as 2 wt% HPSiB incorporated, the HPSiB/bisphenol A cyanate ester (BADCy) resin achieves a UL‐94 V0 rating and 32.4% LOI value, and its peak heat release and total smoke production are simultaneously reduced. Its flexural strength and impact strength were significantly enhanced by 30.0% and 85.4%. Besides, the minimum values of dielectric constant and loss can reach 2.77 and 0.0024 at 10 GHz, which are, respectively, reduced by 7.9% and 88.5%. The integration of unique hyperbranched SiOB backbone of HPSiB with CE crosslinked network was responsible for the enhanced overall performance. This work paves a facile strategy to develop multifunctional flame retardant as a promising candidate for the high‐performance electronic packaging materials.Highlights A novel hyperbranched polyborosiloxane flame retardant was synthesized. HPSiB shows good compatibility and catalyzes the curing reaction of CE resin. HPSiB/CE resin with significantly enhanced flame retardancy was obtained. Simultaneously high toughness and low dielectric loss were achieved. Hyperbranched structure containing SiOB chains led to the great enhancement.

Fatty Acid Composition of Commercial Smoked Salmon Products

In this study, the fatty acid composition of smoked salmon fillets sold in grocery stores in Türkiye was investigated. Gas chromatography (GC) was used to determine fatty acid composition from extracted lipid. The main saturated fatty acids observed in smoked salmon samples were myristic acid (C14:0), palmitic acid (C16:0) and stearic acid (C18:0); monounsaturated fatty acids were palmitoleic acid (C16:1), oleic acid (C18:1n9), and vaccenic acid (C18:1n7); polyunsaturated fatty acids (PUFA) were linoleic acid (C18:2n6), eicosapentaenoic acid (EPA, C20:5n3) and decosahexaenoic acid (DHA, C22:6n3). Among the monounsaturated fatty acids, oleic acid was found to be the fatty acid with the highest value. Oleic acid amounts were found to vary between 27.22% and 35.52%. PUFA values in smoked salmon fillet groups were determined as 27.77%, 27.49%, 32.94% and 30.62%. The highest EPA value was determined in F1 group with 4.29% and the lowest value was determined in F2 group with 2.07%. DHA amounts were between 11.74% and 6.22%. The ratio of Σn6/Σn3 was between 0.80 (F4 group) and 1.16 (F2 group). As a result, it was concluded that the smoked fish fillets examined had high nutritional quality in terms of fatty acids. Among the groups, especially F3 and F4 groups were found to have rich content in terms of PUFA and Σn3 values.

Structure of Metal-Organic Frameworks Eco-Modulated by Acid-Base Balance toward Biobased Flame Retardant in Polyurea Composites.

Biobased-functionalized metal-organic frameworks (Bio-FUN-MOFs) stand out from the crowd of candidates in the flame-retardant field due to their multipathway flame-retardant mechanisms and green synthesis processes. However, exploring and designing Bio-FUN-MOFs tend to counteract the problem of compromising the flame-retardant advantages of MOFs themselves, which inevitably results in a waste of resources. Herein, a strategy in which MOFs are ecologically regulated through acid-base balance is presented for controllable preparation of Bio-FUN-MOFs by two birds with one stone, i.e., higher flame-retardant element loading and retention of more MOF structures. Specifically, the buffer layer is created on the periphery of ZIF-67 by weak etching of biobased alkali arginine to resist the excessive etching of ZIF-67 by phytic acid when loading phosphorus source and to preserve the integrity of internal crystals as much as possible. As a proof of concept, ZIF-67 was almost completely etched out by phytic acid in the absence of arginine. The arginine and phytic acid-functionalized ZIF-67 with yolk@shell structure (ZIF@Arg-Co-PA) obtained by this strategy, as a biobased flame retardant, reduces fire hazards for polyurea composites. At only 5 wt % loading, ZIF@Arg-Co-PA imparted polyurea composites with a limiting oxygen index of 23.2%, and the peaks of heat release rate, total heat release, and total smoke production were reduced by 43.8, 32.3, and 34.3%, respectively, compared to neat polyurea. Additionally, the prepared polyurea composites have acceptable mechanical properties. This work will shed light on the advanced structural design of polymer composites with excellent fire safety, especially environmentally friendly and efficient biobased MOF flame retardants.

P/N/Si-rich and flexible coating imparting polypropylene excellent flame retardancy without compromising its inherent mechanical properties

In general, the addition of flame retardants may lead to the degradation of the mechanical properties of polymers, despite enhancing their flame retardancy. However, flame-retardant coatings have the potential to provide good flame resistance to polymers without compromising their inherent mechanical properties. In this study, we applied highly adhesive and flexible polysiloxane flame-retardant coatings (196 μm) to polypropylene, resulting in reductions of 74.9 %, 58.0 %, 80.0 %, and 56.4 % in peak heat release rate, peak smoke production rate, fire growth rate, and mass loss, respectively. By incorporating the lab-synthesized DOPO-modified polysiloxane (APID), the flame-retardant efficiency of ammonium polyphosphate (APP) was greatly enhanced. The primary film-forming agent, (3-aminopropyl) triethoxysilane (APTES), played a key role in maintaining the compatibility of APP and APID with the coating, as well as facilitating the formation of a robust SiOSi crosslinked network structure that strengthened the resulting char layer. The interactivity between the various components, including hydrogen bonds and crosslinked network structures, contributed to improved uniformity, thermal stability, and adhesion of the coatings. Moreover, the coatings exhibited resistance to ultraviolet radiation and water. Our findings suggest that highly flexible and adhesive flame-retardant coatings hold significant potential for applications in polymer protection. These promising results provide a viable pathway for improving the fire protection of polymers through the use of high-adhesive intumescent flame-retardant coatings.

Functionalized lignin nanoparticles assembled with MXene reinforced polypropylene with favorable UV-aging resistance, electromagnetic shielding effects and superior fire-safety

Deterioration in mechanical performances and aging resistance due to the introduction of flame retardants is a major obstacle for bio-based fire-safety polypropylene (PP). Herein, we reported a kind of functionalized lignin nanoparticles assembled with MXene (MX@LNP), and applied it to construct the flame-retardant PP composites (PP-MA) with superior fire safety, excellent mechanical performance, electromagnetic shielding effects and aging resistance. Specifically, the PP-MA doped with only 18 wt% flame-retardant additives (PP-MA18) achieved the UL-94 V-0 rating. In comparison to pure PP, PP-MA18 presented a greatly decreased peak of heat release rate (pHRR), total heat rate (THR), and peak smoke production rate (pSPR) by 79.7 %, 69.0 % and 75.8 %, respectively, and satisfactory decrease in total flammable and toxic volatiles evolved. The formed fine solid microstructure of carbon residuals effectively promoted the compactness of char layers. More importantly, the nano-effect and the strong interface interaction between the complexed MX@LNP and PP enhanced the tensile strength (45.78 MPa) and elongation at break (725.95 %) of PP-MA. Additionally, the significant ultraviolet absorption and electromagnetic wave dissipation performance of MXene and lignin enabled excellent aging resistance and electromagnetic shielding effects of PP-MA compared with PP. This achieved MX@LNP afforded a novel approach for developing flame retardant materials with excellent application performance.

Preparation of flame retardant and antibacterial polyacrylonitrile based on Cu2+ chelated six-armed star-type flame retardant SCCP and chitosan

In this work, a six-armed star-type flame retardant (SCCP) contained phosphorus, nitrogen and sulfur contents was developed, which was then combined with chitosan (CS) to chelate Cu2+ (SCCP@CS-Cu) and blend with polyacrylonitrile (PAN) to produce flame retardant and antibacterial PAN composite (PAN/SCCP@CS-Cu). TG showed that the residual char of PAN/SCCP@CS-Cu in air and nitrogen atmosphere was as high as 16.41 % and 48.48 % at 800 °C, respectively, which were greater than that of PAN. The LOI value of PAN/SCCP@CS-Cu improved to 33.0 % and the peak heat release rate (PHRR) and total heat release (THR) of the composite were all greatly reduced. In addition, the total smoke production (TSP) of PAN/SCCP@CS-Cu decreased by 73.6 % compared to the control sample. Interestingly, the antibacterial properties of PAN/SCCP@CS-Cu against E. coli and S. aureus reached 98.45 % and 99.33 %. This work provides an insight into developing an environmentally friendly PAN composite with flame retardancy, smoke suppression and antibacterial properties, greatly expanding its application field.

Integrated comprehensive protection coating achieved by ligand engineering modulated MXene@LDH heterojunction with anti-corrosion, electromagnetic wave absorption and fire safety

Harsh marine environment poses great threat to the service of offshore equipment, and the development of multifunctional coatings is crucially important at present. Herein, layered double hydroxides (LDH) was loaded onto transition metal carbides (MXene) to construct MXene@LDH heterojunction via electrostatic self-assembly strategy. Supramolecular ligand (TT) formed by tannic acid and 4′-(4-Boronatophenyl)[2,2′:6′,2'']terpyridine modulated the compatibility of MXene@LDH in epoxy resin (EP) based on ligand engineering strategies, forming TT-MXene@LDH hybridized filler. EP doped TT-MXene@LDH coating (TT-MXene@LDH/EP) exhibited outstanding anti-corrosion, electromagnetic wave absorption (EWA) and flame retardant performance. The charge transfer resistance and minimum reflection loss of TT-MXene@LDH/EP were reached at 4.09×1010 Ω⋅cm2 and −37.05 dB. The total heat release and total smoke production of TT-MXene@ LDH/EP were reduced 24.5 % and 47.2 % in combustion. Thermal conductivity of composite sample was also enhanced with the bridging effect of TT-MXene@LDH. Summarily, prepared comprehensive protective coating with anti-corrosion, EWA and fire safety provides a promising candidate for offshore equipment in harsh environments.

Enhancing flame and electrical surface discharge resistance in silicone rubber composite insulation through aluminium hydroxide, clay, and glass fibre additives

Silicone rubber (SR) is a leading polymer used in electrical outdoor insulation applications due to its superior hydrophobic characteristics. However, the low flame and electrical surface discharge resistance of SR limit its broad viability and challenge its integrity in severe outdoor working conditions. This work attempts to explore the flame retardancy and surface discharge characteristics of SR co-filled with aluminium hydroxide (ATH), nanoclay montmorillonite (MMT), and chopped glass fibre (GF). Results indicate that the incorporation of ATH/MMT/GF could assist in improving the fire and surface discharge resistance of the SR material. It is noted that the maximum average rate of heat emission (MARHE) and total smoke production (TSP) are measured at 24.93 kW/m2 and 0.48 m2 in SRE, relative to 61.29 kW/m2 and 6.02 m2 in SRB. Using finite element analysis (FEA), the maximum electric field strength is computed at 4.66 × 106 V/m in the air gap coupled with a high-voltage (HV) plate and sample. SRE exhibits a higher partial discharge inception voltage (PDIV) value of 2.32 kVrms than its counterparts, while the maximum discharge magnitude (Qmax) is computed at 7095 pC, relative to 7746 pC in SRB. SRE emerges as a preferable SR composite to be used in electrical insulation applications with excellent flame and surface discharge resistance characteristics.

Fabricating advanced MXene-based hybrid materials to elevate fire safety and mechanical strength in carbon fiber-reinforced bismaleimide resins

Bismaleimide (BMI) resin holds great significance to the aerospace field, however, the limited toughness and inadequate fire resistance impede its broader application area. The addition of carbon fiber (CF) can enhance the toughness of BMI resin, but fire safety and interfacial stability between CF and BMI matrix need to be further considered. Here, the carbon fiber-reinforced BMI resin laminate was designed to improve fire resistance, mechanical properties, and interfacial affinity based on a novel P, N, and Si surface-modified flame retardant (MX@HBET) and silane-modified CF. Upon addition of 1 wt% MX@HBET to BMI/CF composites, the total heat release and total smoke production respectively exhibited 10.73 % and 33.3 % reduction. Furthermore, the laminate exhibited significant fire resistance when exposed to butane flame (1500 °C) and the backplane temperature was maintained at approximately 430 °C for 20 min. In addition, the impact and tensile strengths of the laminate respectively reached 82.10 kJ/m2 and 466.6 MPa (pure BMI/CF corresponding to 63.52 kJ/m2 and 350.1 MPa). In brief, the flame resistance and mechanical performance enhanced greatly via the introduction of modified MXene and CF, providing promising prospects for the application of aviation materials in extreme conditions.

Construction of a hybrid flame retardant based on mesoporous silica for enhancing fire safety, smoke suppression, and mechanical properties of epoxy resins

AbstractIn order to improve the fire safety of epoxy resins (EPs), the SBA‐15 based hybrid flame retardant (SNAZD) was synthesized via an organic–inorganic hybridization strategy of mesoporous silica SBA‐15. Relying on electrostatic interaction, the zinc amino‐tris‐(methylenephosphonate) (Zn‐ATMP) was successfully introduced into the pore channels of SBA‐15. Then, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was successfully loaded into the pores of SBA‐15 under vacuum. The results show that the EP composites with the 5%SNAZD sample (sample EP‐5%SNAZD) showed a LOI value of 30.9% and achieved the vertical burning V‐0 rating. In comparison to EP, the peak heat release rate, peak smoke production rate, and production rate of CO of EP‐3%SNAZD were reduced by 32.2%, 31.9%, and 20.0%, respectively. This is due to the presence of Si, P, N, and Zn elements in the SNAZD, which promoted the generation of a high yield of dense char residue and inhibited the release of toxic gasses. And the impact strength and flexural strength of EP‐1%SNAZD were increased by 19.5% and 15.6%, respectively, and the E' of EP‐5%SNAZD increased by 49.1% when compared with the neat EP. This work provides a general strategy for the design of mesoporous hybrid flame retardant and creates additional opportunities for applications of EP.

Eco-friendly flame-retardant bamboo fiber/polypropylene composite based on the immobilization of halloysite nanotubes by tannic acid-Fe3+ complex

Bamboo fibers (BF), as an important sustainable natural material, are becoming a hot alternative to synthetic fibers for the reinforcement of polypropylene (PP)-based composites. However, the weak interfacial compatibility between BF and PP as matrix and their inherent flammability limit the practical application of BF/PP composites (BPC). Here, a fire-safe BPC was fabricated by constructing flame-retardant interfacial layers containing tannic acid (TA)-Fe3+ complex and halloysite nanotubes (HNTs) on the fiber matrix followed by a hot-pressing process. The results showed that the interfacial chelating of TA with Fe3+ improved the dispersion of HNTs on the fibers and the interfacial interactions within the fiber matrix, resulting in the as-fabricated composite with significantly improved mechanical properties and water resistance. In addition, the flame-retardant composite exhibited higher thermal stability and enhanced residual char content. Moreover, the composite possessed significant flame-retardant performances with a reduction of 23.75 % in the total heat release and 32.44 % in the total smoke production, respectively, owing to the flame retarding in gaseous phase and condensed phase of TA-Fe3+@HNTs layers. This work offers a green and eco-friendly strategy to address the inherent problems of BPC material in terms of fire safety and interfacial compatibility, thus broadening their applications in the automotive interior and construction industries.

Design of a Smoker-Dryer for Chicken

Chicken breeders, particularly those in Ngaoundéré-Cameroon, after 45 days of breeding find themselves confronted with the problems of wasting nutrients and resources. In most cases, they sell their chicken at low prices to avoid expenses. Faced with these problems, a few of them use various methods to preserve their chicken after 45 days of breeding, including cold preservation, smoking and drying. Cold preservation is the most widely used technique, but this technique is energy-intensive, without forgetting the untimely power cuts, and the deterioration of the quality of the product. By getting closer to its stakeholders, we were able to identify their difficulties, why they use cold preservation more and they also entrusted us with the characteristics of equipment that could meet their requirements. In this article we presented the results from functional analysis to 3D modeling through the search for solutions to resolve contradictions. It emerges from this study that the designed model guarantees food safety, user safety, retains all nutrients, ergonomic, uses fewer resources, fast, adaptable to any type and size of smoking products and that it is possible to achieve it industrially.

Bio-derived polyphosphazene modified halloysite nanotubes as eco-friendly flame retardants to significantly reduce smoke release and enhance the fire safety of epoxy resin

At present, designing efficient bio-based flame retardants for epoxy resin (EP) and exploring low-toxicity and sustainable flame retardant strategies is still a great challenge. In this work, a novel bio-based hybrid flame retardant was successfully prepared by constructing a resveratrol-based cyclic cross-linked polyphosphazene (PPZ) shell on the surface of halloysite nanotube (HNT). The enhancement effects of HNT@PPZ on the fire safety of EP composites were investigated by thermal degradation, simulated fire performance (cone calorimeter test), gas-phase product analysis, and condensed-phase char residue analysis. Compared to pure EP, he total heat release (THR), total smoke production (TSP) and the average yield of carbon monoxide (Av-COY) of EP/3HNT@PPZ were reduced by 47.8 %, 46.5 % and 48.8 % respectively. Furthermore, the EP composites containing HNT@PPZ had a stable flame retardancy even after 6 months of natural aging. It was found the barrier effect of HNT@PPZ in condensed phase was further strengthened by the formation of new product aluminum phosphate, which formed a multiple protective char layer. Additionally, PPZ shell improved compatibility and dispersion of HNT in EP matrix, the mechanical properties of the composite with HNT@PPZ were improved significantly. This work proposed a feasible solution for the preparation of highly efficient bio-based flame retardants with excellent heat reduction and smoke toxicity reduction ability, which could be expected to broaden the application of biomass resources in the development of highly efficient flame retardants.

Green vanillin coupled with P/N/Si flame retardant for poly (L-lactic acid)

To better solve the flammability of poly (l-lactic acid) (PLLA) and meet environmental concerns, developing bio-derived flame retardants for PLLA is an alternative method. A green flame retardant (VKD) was synthesized in the work. Vanillin was modified using 3-amino-propyl-triethoxysilane (KH550) prior to coupling with 9, 10-dihydro-9-oxa-10-phosphafi-10-oxide (DOPO). As the blend ratio of VKD to PLLA was 20 wt%, the limiting oxygen index (LOI) and UL-94 were 25.5% and V-0 rating, respectively; and the residual carbon rate reached 9.14% at 600 °C, which was 3.3 times higher than that of PLLA. In the cone calorimetry test, the peak heat release rate (pHRR) and total heat released (THR) reduced by 9.9% and 20.5%, respectively, and total smoke production (TSP) decreased by 26.8%, indicating that VKD/PLLA had good flame retardancy and smoke suppression properties. It was mainly attributed to initial condensation phase obstacle and following combination of gaseous phase quenching and carbon/silicon composite barrier. The VKD/PLLA maintained balanceable mechanical properties and good degradation. Then green VKD would broaden PLLA in the application of engineering such as electronic products and automotive interior materials.