scholarly journals Effect of the B:Zn:H2O Molar Ratio on the Properties of Poly(Vinyl Acetate) and Zinc Borate-Based Intumescent Coating Materials Exposed to a Quasi-Real Cellulosic Fire

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2542
Author(s):  
Jakub Łopiński ◽  
Beata Schmidt ◽  
Yongping Bai ◽  
Krzysztof Kowalczyk
Keyword(s):  
Mechanical Strength ◽  
Vinyl Acetate ◽  
Thermal Insulation ◽  
Fire Protection ◽  
Zinc Borate ◽  
Molar Ratio ◽  
Vertical Position ◽  
Coating Materials ◽  
Intumescent Coating ◽  
Chemical Structures

In order to investigate an influence of the B:Zn:H2O molar ratio on the fire protection efficiency of poly(vinyl acetate)-based thermoplastic intumescent coating materials (ICs), systems containing ammonium polyphosphate, melamine, pentaerythritol and different types of zinc borates (ZBs) were tested in a vertical position in quasi-real fire conditions. 3ZnO·2B2O3·6H2O (ZB6), 2ZnO·3B2O3·3.5H2O (ZB3.5) or 3ZnO·2B2O3 (ZB0) were added in amounts of 1–10 wt. parts/100 wt. parts of the other coating components mixture. Char formation processes and thermal insulation features were investigated using an open-flame furnace heated according to the cellulosic fire curve. Thermogravimetric features (DTG), chemical structures (FTIR) and mechanical strength of the ICs and the chars were analyzed as well. It was revealed that the type and dose of the ZBs significantly affect thermal insulation time (TIT) (up to 450 °C of a steel substrate) and sagging (SI) of the fire-heated coatings as well as the compressive strength of the created chars. The highest TIT value (+89%) was noted for the sample with 2.5 wt. parts of ZB3.5 while the lowest SI (−65%) was observed for the coatings containing 10 wt. parts of the hydrated borates (i.e., ZB3.5 or ZB6). The best mechanical strength was registered for the sample filled with the anhydrous modifier (3 wt. parts of ZB0). The presented results show that the ICs with the proper ZBs can be used for effective fire protection of vertically positioned steel elements.

scholarly journals Synthesis and Characterization of Partially Renewable Oleic Acid-Based Ionomers for Proton Exchange Membranes

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Proton Conductivity ◽  
Electrochemical Impedance ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Molar Ratio ◽  
Aromatic Diamines ◽  
Chemical Structures ◽  
Long Chain

The future availability of synthetic polymers is compromised due to the continuous depletion of fossil reserves; thus, the quest for sustainable and eco-friendly specialty polymers is of the utmost importance to ensure our lifestyle. In this regard, this study reports on the use of oleic acid as a renewable source to develop new ionomers intended for proton exchange membranes. Firstly, the cross-metathesis of oleic acid was conducted to yield a renewable and unsaturated long-chain aliphatic dicarboxylic acid, which was further subjected to polycondensation reactions with two aromatic diamines, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline and 4,4′-diamino-2,2′-stilbenedisulfonic acid, as comonomers for the synthesis of a series of partially renewable aromatic-aliphatic polyamides with an increasing degree of sulfonation (DS). The polymer chemical structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F NMR) spectroscopy, which revealed that the DS was effectively tailored by adjusting the feed molar ratio of the diamines. Next, we performed a study involving the ion exchange capacity, the water uptake, and the proton conductivity in membranes prepared from these partially renewable long-chain polyamides, along with a thorough characterization of the thermomechanical and physical properties. The highest value of the proton conductivity determined by electrochemical impedance spectroscopy (EIS) was found to be 1.55 mS cm−1 at 30 °C after activation of the polymer membrane.

scholarly journals Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Hang Xu ◽  
Tianlong Yu ◽  
Mei Li
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Vinyl Acetate ◽  
Silica Gel ◽  
Catalyst Activity ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Molar Ratio ◽  
Vinyl Acetate Monomer ◽  
Adsorption Desorption

Ionic liquid containing active ingredient Zn(CH3COO)2was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC) which was used to synthesize vinyl acetate monomer (VAM). SILC was characterized by1HNMR, FT-IR, TGA, BET, and N2adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc) conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc) selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV). The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

scholarly journals Cytotoxicity of Catalysed Silicone Resin Coatings for Smart Biomedical Devices

2019 ◽  
Vol 5 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Valerie M. K. Werner ◽  
Arian Kist ◽  
Markus Eblenkamp
Keyword(s):  
Cytotoxic Effect ◽  
Polymer Coatings ◽  
Silicone Resin ◽  
Electronic Systems ◽  
Biomedical Devices ◽  
Coating Materials ◽  
Organometallic Catalysts ◽  
Chemical Structures ◽  
Integration Strategies ◽  
Smart Technologies

AbstractEquipping medical devices with smart technologies holds great potential for the development of modern medical products. The development requires the identification of new integration strategies and the research of new material combinations due to the miniaturization of systems and increasing production figures. The realization of Smart Biomedical Devices requires a sufficient barrier effect (bioprotection) by appropriate encapsulation of the electronic components. Thinnest polymer coatings have proven to be suitable for conformal encapsulation. The aim of the study was to investigate the fundamental suitability of thin-film lacquers added with catalysts as coating materials for electronic systems with regard to their biological use. Due to long curing times of up to 14 days, eight different catalysts based on different chemical structures were added to the coating materials and their influence on a cytotoxic effect was investigated. A non-cytotoxic effect was observed for the organometallic catalysts based on tin, zirconium, titanium, bismuth, and tertiary amine. Most were resistant to steam sterilization. The curing time of the non-cytotoxic coatings could be significantly reduced by the addition of catalysts. The shortening of process times is an important economic aspect in the production of mass-produced Smart Biomedical Devices.

scholarly journals Combustible Material Content vs. Fire Properties of Electric Cables

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6172
Author(s):  
Katarzyna Kaczorek-Chrobak ◽  
Jadwiga Fangrat
Keyword(s):  
Heat Release ◽  
Combustion Process ◽  
Test Method ◽  
Zinc Borate ◽  
Infrared Analysis ◽  
Chemical Structures ◽  
Smoke Production ◽  
Outer Sheath ◽  
Electric Cables ◽  
Fire Properties

The fire load of buildings is significantly increased by means of electric cables, usually creating a long combustible base for fire to spread and in this way decreasing the fire safety of buildings. The aim of the study was to evaluate a relationship between the construction of the cables and their fire properties, especially the mass loss influence on other fire properties of cables. Six cables of different core numbers were tested by means of the standard test method EN 50399. Additionally, thermogravimetric analysis and Attenuated Total Reflection—Fourier Transform Infrared analysis were performed on the separate outer sheath, bedding, and core insulations in order to determine the similarity of the materials’ chemical structures. It was found that: (1) the construction of the cable strongly influences the fire behavior due to the creation of a barrier for flame penetration and emission of combustion effluents though inside the closed agglomeration of non-combustible metallic cores (conductors), and the intumescent structures formed from aluminum trihydrate/zinc borate fillers and fire retardants in outer sheath material during the self-sustained combustion process after ignition of cables; (2) the inhomogeneous distribution of non-combustible inorganic fillers or different contents of fillers and flame retardants within the polymer fraction cause an unobvious fire behaviors of cables; and (3) the use of bedding in multicore cable construction results in lower values of combustion parameters (maximum average heat release rate, total heat release, maximum average smoke production rate, total smoke production), e.g., better fire properties of cables.

Effect of Water Reducer and Cellulose Ether on Sulphoaluminate Cement-Based Lightweight Thermal Insulation Board

2014 ◽  
Vol 541-542 ◽  
pp. 273-276
Author(s):  
Xiao Nan Dong ◽  
Xi Chen ◽  
Ling Chao Lu ◽  
Shuai Yang
Keyword(s):  
Mechanical Strength ◽  
Thermal Insulation ◽  
Influential Factor ◽  
Cellulose Ether ◽  
Dry Density ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Sulphoaluminate Cement ◽  
Effect Of Water ◽  
Good Workability

The effects of two admixtures content i.e. water reducer, cellulose ether and water-cement ratio on mechanical strength and dry density of cement-based lightweight thermal insulation board are studied. The result indicates that the water-cement ratio is the important influential factor, which is easier to get good workability. And based on the mechanical strength and dry density, the best range of water reducer content and cellulose ether content are 0.3%-0.6% and 0.4%-0.6% respectively.

scholarly journals Industrial Thermal Insulation Properties above Sintering Temperatures

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4721
Author(s):  
Amalie Gunnarshaug ◽  
Maria-Monika Metallinou ◽  
Torgrim Log
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Thermal Insulation ◽  
Fire Protection ◽  
Thermal Transport ◽  
Amorphous Materials ◽  
Transport Theory ◽  
Treatment Temperature ◽  
Dimensional Changes ◽  
Passive Fire Protection

Processing highly flammable products, the oil and gas (O&G) industry can experience major explosions and fires, which may expose pressurized equipment to high thermal loads. In 2020, oil fires occurred at two Norwegian O&G processing plants. To reduce the escalation risk, passive fire protection may serve as a consequence-reducing barrier. For heat or cold conservation, equipment and piping often require thermal insulation, which may offer some fire protection. In the present study, a representative thermal insulation (certified up to 700 °C) was examined with respect to dimensional changes and thermal transport properties after heat treatment to temperatures in the range of 700 °C to 1200 °C. Post heat treatment, the thermal conductivity of each test specimen was recorded at ambient temperature and up to 700 °C, which was the upper limit for the applied measurement method. Based on thermal transport theory for porous and/or amorphous materials, the thermal conductivity at the heat treatment temperature above 700 °C was estimated by extrapolation. The dimensional changes due to, e.g., sintering, were also analyzed. Empirical equations describing the thermal conductivity, the dimensional changes and possible crack formation were developed. It should be noted that the thermal insulation degradation, especially at temperatures approaching 1200 °C, is massive. Thus, future numerical modeling may be difficult above 1150 °C, due to abrupt changes in properties as well as crack development and crack tortuosity. However, if the thermal insulation is protected by a thin layer of more robust material, e.g., passive fire protection to keep the thermal insulation at temperatures below 1100 °C, future modeling seems promising.

Experimental and Numerical Investigations of Steel Profiles with Intumescent Coating Adjacent to Space-Enclosing Elements in Fire

2015 ◽  
Vol 6 (4) ◽  
pp. 237-246 ◽  
Author(s):  
Peter Kraus ◽  
Martin Mensinger ◽  
Florian Tabeling ◽  
Peter Schaumann
Keyword(s):  
Temperature Field ◽  
Numerical Model ◽  
Fire Protection ◽  
Experimental Investigations ◽  
Expansion Process ◽  
Intumescent Coating ◽  
Numerical Investigations ◽  
Steel Members ◽  
New Development ◽  
In Fire

In this paper, the research program “Optimized use of intumescent coating systems on steel members” is presented. The aim of the project is to quantify the influence of space-enclosing elements on the thermal behavior of supporting steel members. Those elements partially result in a restrained expansion of the fire protection system. Experimental investigations on coated beams and columns directly connected to space-enclosing elements are presented. Additionally, numerical simulations are performed for temperature field calculations of steel elements with intumescent coating. As a new development, the numerical model takes into account the expansion process of the intumescent coating.

Synthesis, characterization and enzymatic degradation of copolymers of ε-caprolactone and hydroxy-fatty acids

2016 ◽  
Vol 88 (12) ◽  
pp. 1191-1201 ◽  
Author(s):  
Diana Aparaschivei ◽  
Anamaria Todea ◽  
Iulia Păuşescu ◽  
Valentin Badea ◽  
Mihai Medeleanu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Degradation Products ◽  
Hydroxy Fatty Acids ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Buffer Solutions ◽  
Different Temperatures ◽  
Ft Ir ◽  
Candida Antarctica B

AbstractNew copolymers of ε-caprolactone with three hydroxy-fatty acids, 12-hydroxy stearic acid, 16-hydroxyhexadecanoic acid and ricinoleic acid, were synthesized by catalytic polyesterification. The reactions were carried out in solvent-free systems and in organic solvents as well, using tin(II) 2-ethylhexanoate as catalyst, at different temperatures and molar ratios of the comonomers. Cyclic and linear polymeric products with medium molar weight of about 2000 Da have been synthesized and their chemical structures were confirmed by FT-IR, NMR and MALDI-TOF MS analysis. The synthesis parameters were optimized and the ε-caprolactone/hydroxy acid molar ratio was set as 5:1, according to mass spectrometry results. The biodegradability of the newly synthesized polymers was studied in the presence of Candida antarctica B lipase in phosphate buffer solutions (pH=7.4), at 37°C. The weight-loss profile emphasized the degradation of the 16-hydroxyhexadecanoic acid based polymer samples at more than 50% of their initial weight in 18 days of incubation in the presence of the lipase. The composition of the degradation products was assessed using the GC-MS technique and displayed residues of the comonomers moieties.

Synthesis and Self-Assemble Behavior of Block Copolymerization of Vinyl Acetate and N-Vinylacetamide

2013 ◽  
Vol 645 ◽  
pp. 10-14
Author(s):  
Yu Lou ◽  
Dong Jian Shi ◽  
Wei Fu Dong ◽  
Ming Qing Chen
Keyword(s):  
Block Copolymer ◽  
Radical Polymerization ◽  
Vinyl Acetate ◽  
Microphase Separation ◽  
Molar Ratio ◽  
Block Copolymerization ◽  
Bulk State ◽  
Self Assembled

Polymerizations of VAc was carried out using AIBN as the initiator and DIP as the MADIX agent precursor. Then, block copolymer PVAc-b-PNVA had been synthesized by RAFT radical polymerization in the presence of PVAc-DIP as macro CTA. The length of blocks could be tuned by changing the molar ratio of NVA and VAc. Block copolymer PVAc-b-PNVA self-assembled into micelles in solution, and underwent microphase separation in bulk state.

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