scholarly journals Modification and Compounding of CaMgAl-Layered Double Hydroxides and Their Application in the Flame Retardance of Acrylonitrile-Butadiene-Styrene Resin

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1623 ◽  
Author(s):  
Bai-nian Wang ◽  
Ming-yang Chen ◽  
Bao-jun Yang

CaMgAl-layered double hydroxides (CaMgAl-LDHs) were synthesized by a co-precipitation method to prepare sodium oleate-modified, borate-intercalated CaMgAl-LDHs (O-CaMgAl-LDHs) using in-situ intercalation and modification, and the LDHs samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), and thermal gravimetric analysis (TGA). The FESEM observations showed that the as-prepared CaMgAl-LDHs had a lamellar structure with a particle size of 200~500 nm, while the O-CaMgAl-LDHs had a plate-like structure with a particle size of about 100 nm. TGA showed that O-CaMgAl-LDHs resulted in higher thermal stability at high temperature compared to CaMgAl-LDHs. O-CaMgAl-LDHs/ABS composites were prepared by adding O-CaMgAl-LDHs to acrylonitrile-butadiene-styrene resin (ABS) to test the resulting flame retardancy and mechanical properties, and the results showed that the limiting oxygen index (LOI) could increase from 18% to 26%, while the mechanical properties decreased significantly when the added fraction was 40% (relative to ABS). O-CaMgAl-LDHs, ammonium polyphosphate (APP) and expandable graphite (EG) were added into the ABS to prepare ABS composites, and the effects of different compositions on the flame retardancy and mechanical properties of the ABS composites were investigated. The results showed that, when adding 5 g of O-CaMgAl-LDHs, 1 g of APP, and 14 g of EG into 40 g of ABS, the LOI of the ABS composite reached 28.8%, and the composite prepared could meet the V-0 grade requirements of the UL-94 combustion test, while the flexural strength decreased only 21.9% compared to pure ABS, the smallest decrease compared to all of the other composites.

RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49143-49152 ◽  
Author(s):  
Ningjing Wu ◽  
Zhaoxia Xiu

Silicone-microencapsulated aluminum hypophosphite (SiAHP) improved effectively the flame retardancy and significantly enhanced the notched impact strength of ABS/SiAHP composites.


2020 ◽  
pp. 089270572092513
Author(s):  
Xincheng Guo ◽  
Nian Liu ◽  
Lingtong Li ◽  
Zhuyu Bai ◽  
Xiaolang Chen ◽  
...  

In this article, the flammable behaviors and synergistic effects of modified expanded graphite (MEG) with zinc borate (ZB) on flame-retardant high-density polyethylene/ethylene vinyl acetate (HDPE/EVA) composites containing magnesium hydroxide (MH) and aluminum hydroxide (ATH) are investigated by the Underwriters Laboratories-94 (UL-94) test, limiting oxygen index (LOI), cone calorimeter test (CCT), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), differential scanning calorimetry, and tensile tests. The LOI, UL-94, and CCT results show that the synergistic effect of MEG and ZB can improve the flame retardancy of the composites. With the addition of ZB and MEG, the LOI value increases, and the UL-94 reaches the V-0 rating. The heat release rate and total heat release decrease, respectively. The data obtained from the TGA indicate that the synergistic effects of ZB with MEG increase the decomposition temperature when 2 phr ZB and 8 phr MEG are added into the composites. The data from FTIR show that HMEG8 and HMEG10 composites produce phosphate at high temperatures, which promotes the formation of stable and compact charred layer. All the results show that ZB and MEG have positive synergistic effects on HDPE/EVA composites containing MH and ATH. However, ZB and MEG play a negative role in the tensile properties of the HDPE/EVA composites.


2015 ◽  
Vol 3 (13) ◽  
pp. 6819-6826 ◽  
Author(s):  
Ehsan Naderi Kalali ◽  
Xin Wang ◽  
De-Yi Wang

Aiming at developing highly efficient nano fire retardants and fire retarding epoxy resins, a series of functionalized layered double hydroxides (LDHs) based on a multi-modifier system have been developed. These functionalized LDHs were used as novel nano flame-retardants for bisphenol epoxy resins and compared with unmodified LDHs.


2019 ◽  
pp. 089270571988601 ◽  
Author(s):  
Sahil Kapoor ◽  
Meenakshi Goyal ◽  
Prashant Jindal

Nanocomposites of acrylonitrile butadiene styrene (ABS) with multi-walled carbon nanotubes (MWCNTs) have been fabricated using a facile solution blending technique with the variable weight of MWCNTs in ABS within a range of 1–5 wt% in the ABS/MWCNTs nanocomposites. Morphological characterization using field emission scanning electron microscope has shown uniform dispersion of MWCNTs in the nanocomposites. Thermal gravimetric analysis has shown improved thermal degradation stability for 5 wt% ABS/MWCNTs nanocomposites in comparison to pure ABS. Thermal expansion analysis of ABS/MWCNTs nanocomposites also showed a significant reduction in thermal strain and coefficient of thermal expansion (CTE) in comparison to pure ABS, with the 5 wt% sample showing a maximum reduction in thermal expansion properties. Mechanical characterization for 5 wt% ABS/MWCNTs nanocomposite, using nanoindentation, showed significant improvement in elastic modulus (90%) and hardness (99%) in comparison to pure ABS. The dynamic mechanical properties of 5 wt% ABS/MWCNTs nanocomposites also showed significant improvement with storage modulus and hardness improving by 153% and 342%, respectively, in comparison to pure ABS. These enhanced thermal and mechanical properties of ABS/MWCNTs nanocomposites enable their applications for a wider scope in various areas of engineering-based application, especially in the automobile industry.


2015 ◽  
Vol 37 (9) ◽  
pp. 2673-2683 ◽  
Author(s):  
Xiuyan Pang ◽  
Xiuzhu Shi ◽  
Xiaoou Kang ◽  
Mingwei Duan ◽  
Mengqi Weng

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.


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