Design and preparation of new polypropylene/magnesium oxide micro particles composites reinforced with hydroxyapatite nanoparticles: A study of thermal stability, flame retardancy and mechanical properties

2021 ◽  
Vol 258 ◽  
pp. 123917
Author(s):  
Mohsen Hajibeygi ◽  
Masoumeh Mousavi ◽  
Meisam Shabanian ◽  
Navid Habibnejad ◽  
Henri Vahabi
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Magnesium Oxide ◽  
Flame Retardancy ◽  
Hydroxyapatite Nanoparticles ◽  
Micro Particles

Expanded vermiculite-filled flexible polymer composites

2021 ◽  
pp. 009524432110290
Author(s):  
Mukaddes Sevval Cetin ◽  
Ozan Toprakci ◽  
Omer Suat Taskin ◽  
Abdullah Aksu ◽  
Hatice Aylin Karahan Toprakci
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Contact Angle ◽  
Polymer Composites ◽  
Flame Retardancy ◽  
Composite Films ◽  
Filler Concentration ◽  
High Shear ◽  
Flexible Polymer ◽  
Shear Mixing

This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.

Effect of Nanometer Magnesium Oxide Addition on the Cast Microstructure of X80 Pipeline Steel

2013 ◽  
Vol 401-403 ◽  
pp. 610-613
Author(s):  
Jian Ming Wang ◽  
Yang Liu ◽  
Yan Liu ◽  
Qian He Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Magnesium Oxide ◽  
Pipeline Steel ◽  
Harsh Environment ◽  
Second Phase ◽  
X80 Pipeline Steel ◽  
Oxide Addition ◽  
Second Phase Particles ◽  
Cast Microstructure

The pipeline steel as an application in pipeline construction must have good comprehensive mechanical properties due to the harsh environment of the pipeline engineering. So this experiment takes the X80 pipeline steel as the research object, the thermal stability second phase particles which would not be dissolved or aggregated at high temperature will be expected by means of adding nanomagnesium oxide into the steel with the method of carrier dispersion addition. The effect of nanometer magnesium oxide addition on the cast microstructure of X80 pipeline steel was analysed. The results show that the cast microstructure is consist of the ferrite and a small amount bainite. And the bainite is distributed at the boundary of the ferrite grains. When adding 0.02 wt% nanometer magnesium oxides, the number of bainite increases significantly in the cast microstructure, which is mostly distributed at the boundary of the ferrite grains.

scholarly journals Highly Efficient Composite Flame Retardants for Improving the Flame Retardancy, Thermal Stability, Smoke Suppression, and Mechanical Properties of EVA

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1251
Author(s):  
Yilin Liu ◽  
Bin Li ◽  
Miaojun Xu ◽  
Lili Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardant ◽  
Production Rate ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Mass Loss Rate ◽  
Smoke Suppression ◽  
Average Mass

Ethylene vinyl acetate (EVA) copolymer has been used extensively in many fields. However, EVA is flammable and releases CO gas during burning. In this work, a composite flame retardant with ammonium polyphosphate (APP), a charring–foaming agent (CFA), and a layered double hydroxide (LDH) containing rare-earth elements (REEs) was obtained and used to improve the flame retardancy, thermal stability, and smoke suppression for an EVA matrix. The thermal analysis showed that the maximum thermal degradation temperature of all composites increased by more than 37 °C compared with that of pure EVA. S-LaMgAl/APP/CFA/EVA, S-CeMgAl/APP/CFA/EVA, and S-NdMgAl/APP/CFA/EVA could achieve self-extinguishing behavior according to the UL-94 tests (V-0 rating). The peak heat release rate (pk-HRR) indicated that all LDHs containing REEs obviously reduced the fire strength in comparison with S-MgAl. In particular, pk-HRR of S-LaMgAl/APP/CFA/EVA, S-CeMgAl/APP/CFA/EVA and S-NdMgAl/APP/CFA/EVA were all decreased by more than 82% in comparison with pure EVA. Furthermore, the total heat release (THR), smoke production rate (SPR), and production rate of CO (COP) also decreased significantly. The average mass loss rate (AMLR) confirmed that the flame retardant exerted an effect in the condensed phase of the composites. Meanwhile, the combination of APP, CFA, and LDH containing REEs allowed the EVA matrix to maintain good mechanical properties.

scholarly journals Novel Intumescent Flame Retardant Masterbatch Prepared Through Different Processes and Its Application in EPDM/PP Thermoplastic Elastomer: Thermal Stability, Flame Retardancy, and Mechanical Properties

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 50 ◽  
Author(s):  
Weidi He ◽  
Ying Zhou ◽  
Xiaolang Chen ◽  
Jianbing Guo ◽  
Dengfeng Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Thermoplastic Elastomer ◽  
Molar Ratio ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Properties Of Materials ◽  
Intumescent Flame Retardants

In this work, the ethylene-propylene-diene monomer/polypropylene (EPDM/PP) thermoplastic elastomer filled with intumescent flame retardants (IFR) is fabricated by melting blend. The IFR are constituted with melamine phosphate-pentaerythritol (MP/PER) by compounding and reactive extruding, respectively. The effects of two kinds of MP/PER with different contents on the thermal stability, flame retardancy, and mechanical properties of materials are investigated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94, cone calorimeter test (CCT), and scanning electron microscopy (SEM). FTIR results show that the reactive extruded MP/PER partly generates melamine pyrophosphate (MPP) compared with compound masterbatches. TGA data indicate that the best thermal stability is achieved when the molar ratio of MP/PER reaches 1.8. All the reactive samples show a higher flame retardancy than compound ones. The CCT results also exhibit the same trend as above in heat release and smoke production rate. The EPDM/PP composites filled with 30 and 35% reactive MP/PER exhibit the improved flame retardancy but become stiffer and more brittle. SEM photos display that better dispersion and smaller particle size are obtained for reactive samples.

Sign in / Sign up

Export Citation Format

Share Document