scholarly journals Effects of Aluminum Hydroxide and Layered Double Hydroxide on Asphalt Fire Resistance

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1939 ◽  
Author(s):  
Menglin Li ◽  
Ling Pang ◽  
Meizhu Chen ◽  
Jun Xie ◽  
Quantao Liu
Keyword(s):  
Carbon Monoxide ◽  
Layered Double Hydroxide ◽  
Aluminum Hydroxide ◽  
Fire Resistance ◽  
Flame Retardants ◽  
Synergistic Effects ◽  
Combined System ◽  
Limiting Oxygen Index ◽  
Double Hydroxide ◽  
The Impact

When a fire occurs in a tunnel, the instantaneous high temperature and smoke cause great danger to people. Therefore, the asphalt pavement material in the tunnel must have sufficient fire resistance. In this study, the effects of aluminum hydroxide and layered double hydroxide on the fire resistance of styrene-butadiene-styrene (SBS) polymer-modified asphalt was investigated. The fire resistance of the asphalt was evaluated by using a limiting oxygen index (LOI). The impact of aluminum hydroxide (ATH), layered double hydroxide (LDHs), and mixed flame retardant (MFR) on LOI was studied. The synergistic fire resistance mechanism of ATH and LDHs in asphalt binder was analyzed by using an integrated thermal analyzer‒mass spectrometry combined system (TG-DSC-MS) and Fourier transform infrared spectrometer (FTIR). The experimental results indicated that the main active temperature range of these flame retardants was 221–483 °C. The main components of smoke were methane, hydroxyl, water, carbon monoxide, aldehyde, carbon dioxide, etc. The addition of flame retardants could inhibit the production of methane, carbon monoxide, and aldehyde. Moreover, due to the good synergistic effects of ATH and LDHs, 20 wt % MFR had the best fire resistance.

Enhanced properties of poly(lactic acid) by concurrent addition of organo-modified Mg-Al layered double hydroxide (LDH) and triethyl citrate

2019 ◽  
pp. 089270571986827 ◽  
Author(s):  
Mehrnoush Monshizadeh ◽  
Sajad Seifi ◽  
Iman Hejazi ◽  
Javad Seyfi ◽  
Hossein Ali Khonakdar
Keyword(s):  
Lactic Acid ◽  
Layered Double Hydroxide ◽  
Food Packaging ◽  
Synergistic Effects ◽  
Poly Lactic Acid ◽  
Solution Casting ◽  
Scanning Calorimetry ◽  
Concurrent Use ◽  
Triethyl Citrate ◽  
Double Hydroxide

Synergistic effects of organo-modified Mg-Al layered double hydroxide (LDH) and triethyl citrate (TEC) on the properties of poly(lactic acid) (PLA) were demonstrated. PLA/LDH nanocomposites in the absence and presence of TEC were fabricated via solution casting technique. Morphological analysis revealed that as the LDH concentration increases, the number of aggregations is also increased; however, introduction of TEC considerably enhanced the dispersion quality of LDHs. Differential scanning calorimetry results showed that the addition of LDH and TEC had no significant influence on the crystallinity of nanocomposites obtained from solution casting. In contrast, once the samples were cooled from melt, the concurrent use of LDH and TEC led to a dramatic enhancement in the crystallinity of PLA ( X c = 55.5%). Moreover, the LDH nanoparticles counterbalanced the adverse effects of plasticization by TEC leading to enhanced toughness of the final nanocomposites. LDH had also a positive influence on thermal stability of PLA, indicating the heat-insulating role of LDH particles. In conclusion, the concurrent use of LDH and TEC could extend the applicability of PLA especially in food packaging applications.

scholarly journals The Impact of Magnesium–Aluminum-Layered Double Hydroxide-Based Polyvinyl Alcohol Coated on Magnetite on the Preparation of Core-Shell Nanoparticles as a Drug Delivery Agent

2019 ◽  
Vol 20 (15) ◽  
pp. 3764 ◽  
Author(s):  
Mona Ebadi ◽  
Kalaivani Buskaran ◽  
Bullo Saifullah ◽  
Sharida Fakurazi ◽  
Mohd Zobir Hussein
Keyword(s):  
Drug Delivery ◽  
Polyvinyl Alcohol ◽  
Drug Delivery System ◽  
Layered Double Hydroxide ◽  
Delivery System ◽  
The Body ◽  
Normal Fibroblast ◽  
Cellular Environment ◽  
Double Hydroxide ◽  
The Impact

One of the current developments in drug research is the controlled release formulation of drugs, which can be released in a controlled manner at a specific target in the body. Due to the diverse physical and chemical properties of various drugs, a smart drug delivery system is highly sought after. The present study aimed to develop a novel drug delivery system using magnetite nanoparticles as the core and coated with polyvinyl alcohol (PVA), a drug 5-fluorouracil (5FU) and Mg–Al-layered double hydroxide (MLDH) for the formation of FPVA-FU-MLDH nanoparticles. The existence of the coated nanoparticles was supported by various physico-chemical analyses. In addition, the drug content, kinetics, and mechanism of drug release also were studied. 5-fluorouracil (5FU) was found to be released in a controlled manner from the nanoparticles at pH = 4.8 (representing the cancerous cellular environment) and pH = 7.4 (representing the blood environment), governed by pseudo-second-order kinetics. The cytotoxicity study revealed that the anticancer delivery system of FPVA-FU-MLDH nanoparticles showed much better anticancer activity than the free drug, 5FU, against liver cancer and HepG2 cells, and at the same time, it was found to be less toxic to the normal fibroblast 3T3 cells.

scholarly journals Layered Double Hydroxide (MgFeAl-LDH)-Based Polypropylene (PP) Nanocomposite: Mechanical Properties and Thermal Degradation

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3452
Author(s):  
Sajid Naseem ◽  
Sven Wießner ◽  
Ines Kühnert ◽  
Andreas Leuteritz
Keyword(s):  
Mechanical Properties ◽  
Thermal Degradation ◽  
Layered Double Hydroxide ◽  
Testing Machine ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Small Scale ◽  
Melt Mixing ◽  
Limiting Oxygen Index ◽  
Double Hydroxide

This work analyzes the thermal degradation and mechanical properties of iron (Fe)-containing MgAl layered double hydroxide (LDH)-based polypropylene (PP) nanocomposite. Ternary metal (MgFeAl) LDHs were prepared using the urea hydrolysis method, and Fe was used in two different concentrations (5 and 10 mol%). Nanocomposites containing MgFeAl-LDH and PP were prepared using the melt mixing method by a small-scale compounder. Three different loadings of LDHs were used in PP (2.5, 5, and 7.5 wt%). Rheological properties were determined by rheometer, and flammability was studied using the limiting oxygen index (LOI) and UL94 (V and HB). Color parameters (L*, a*, b*) and opacity of PP nanocomposites were measured with a spectrophotometer. Mechanical properties were analyzed with a universal testing machine (UTM) and Charpy impact test. The thermal behavior of MgFeAl-LDH/PP nanocomposites was studied using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The morphology of LDH/PP nanocomposites was analyzed with a scanning electron microscope (SEM). A decrease in melt viscosity and increase in burning rate were observed in the case of iron (Fe)-based PP nanocomposites. A decrease in mechanical properties interpreted as increased catalytic degradation was also observed in iron (Fe)-containing PP nanocomposites. Such types of LDH/PP nanocomposites can be useful where faster degradation or faster recycling of polymer nanocomposites is required because of environmental issues.

scholarly journals Flame Retardancy Properties and Physicochemical Characteristics of Polyurea-Based Coatings Containing Flame Retardants Based on Aluminum Hydroxide, Resorcinol Bis(Diphenyl Phosphate), and Tris Chloropropyl Phosphate

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5168
Author(s):  
Wojciech Dukarski ◽  
Piotr Krzyżanowski ◽  
Marcin Gonsior ◽  
Iwona Rykowska
Keyword(s):  
Mechanical Properties ◽  
Aluminum Hydroxide ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Good Alternative ◽  
Physicochemical Characteristics ◽  
Limiting Oxygen Index ◽  
Diphenyl Phosphate ◽  
Further Development

Polyurea is a synthetic material made by the reaction of isocyanate and polymer blend-containing amines. Due to its outstanding mechanical properties and fast curing, polyurea-based coatings have found dozens of applications, including waterproofing and anti-corrosion coatings. Further development of this material can create a flame-retardant product, a good alternative for common products available on the market, such as intumescent coatings. To improve the flame retardancy of polyurea, several flame retardants were investigated. The influence of aluminum hydroxide, resorcinol bis(diphenyl phosphate) (RDP), and tris chloropropyl phosphate (TCPP) on flame retardancy and morphology was studied. The following methods were used: infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, limiting oxygen index, and tensile strength. The examinations mentioned above showed the improvement of flame-retardancy of polyurea for two products: chlorinated organophosphate and organophosphate. Nevertheless, using the chlorinated organophosphate additive caused a rapid deterioration of mechanical properties.

Recent developments in fire-retardant thermoset resins using inorganic-organic hybrid flame retardants

2018 ◽  
Vol 38 (6) ◽  
pp. 563-571 ◽  
Author(s):  
Ewa Kicko-Walczak ◽  
Grażyna Rymarz
Keyword(s):  
Flame Retardants ◽  
Fire Retardant ◽  
Polymeric Materials ◽  
Expandable Graphite ◽  
Limiting Oxygen Index ◽  
Thermoset Resins ◽  
Organic Hybrid ◽  
Thermoset Resin ◽  
Recent Developments ◽  
The Impact

Abstract Inorganic-organic hybrid modifiers have attracted attention of scholars worldwide because they combine the advantages of both different components and provide a way for modifying the structure and properties of polymeric materials. The article describes and investigates a positive effect of reduced flammability of thermoset resins resulting from the use of nanocomposites containing new inorganic-organic hybrid flame retardants (FRs) that combine conventional phosphorous/nitrogen modifiers interacting with nanofillers. The impact of these inhibitors on the level of flammability of thermoset resin compositions was defined by determining the value of limiting oxygen index, thermogravimetric and cone calorimeter analysis of thermal destruction processes. Morphology of composites was assessed using a scanning microscope and an analysis of actual scanning electron micrographic images. The analysis of thermal decomposition of the materials under examination confirmed flammability reducing properties of the inorganic-organic hybrid FR used, and a synergist to generate integrated flame retarding effect was observed between conventional modifiers and nanofillers, in particular carbon nanofillers: expandable graphite, graphene and graphene oxide. The inorganic-organic hybrid FR will provide a new solution to efficient FR polymeric materials.

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