scholarly journals Ammonium Polyphosphate Intercalated Layered Double Hydroxide and Zinc Borate as Highly Efficient Flame Retardant Nanofillers for Polypropylene

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1114 ◽  
Author(s):  
Yanshan Gao ◽  
Qiang Wang ◽  
Weiran Lin
Keyword(s):  
Flame Retardant ◽  
Ammonium Polyphosphate ◽  
Zinc Borate ◽  
Polypropylene Composites ◽  
Flame Retardant Property ◽  
Thermogravimetric Analyzer ◽  
Mixing Method ◽  
And Performance ◽  
Double Hydroxide ◽  
Double Hydroxides

We found in our previous study that layered double hydroxides (LDHs) which undergo aqueous miscible organic solvent treatment (AMOST) can tune the hydrophobicity surface of LDHs to be hydrophobic, and then the solvent mixing method can be used to prepare polymer/LDH nanocomposites. However, flame retardant property is not very high if LDHs are only used. In this present work, ammonium polyphosphate (APP) intercalated LDHs and zinc borate (ZB) was incorporated into a polypropylene (PP) matrix using the solvent mixing method. The structures, morphologies, and performance of the composites were characterized carefully. The peak heat release rate (PHRR) reduction of PP containing 10 and 20 wt % APP-LDH reached 27% and 55%, respectively, which increased up to 63% compared with PP/CO3-LDH. After incorporating 2 wt % ZB in the PP/APP-LDH system, the flame retardant property was further improved. Polypropylene composites with 20 wt % APP-LDH and 2 wt % ZB showed a 58% PHRR reduction. In addition, thermogravimetric analyzer (TGA) results indicated that the addition of APP-LDH and ZB improved the temperature at 50% weight loss (T50%) and the char formation of the materials significantly.

Tensile properties and fire residue morphology of flame-retarded-polypropylene composites

2020 ◽  
pp. 089270572092512
Author(s):  
Ji-Zhao Liang
Keyword(s):  
Flame Retardant ◽  
Tensile Properties ◽  
Flame Retardants ◽  
Volume Fraction ◽  
Tensile Elongation ◽  
Zinc Borate ◽  
Tensile Yield Strength ◽  
Tensile Fracture ◽  
Polypropylene Composites ◽  
Flame Retarded

The polypropylene (PP) composites filled with flame retardants (including aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), and zinc borate (ZB)) were prepared, and the composites were separately loaded with polyolefin elastomer (POE) and nanometer calcium carbonate (nano-CaCO3). The tensile properties and the fire residue morphology of the specimens after burning for these three groups of composites were measured. The results were shown that the tensile fracture strength and the Young’s modulus increased while the tensile yield strength and the tensile elongation at break ( δ b) decreased with increasing flame-retardant volume fraction. At the same flame-retardant content, the δ b values of the PP/Al(OH)3/Mg(OH)2/ZB/nano-CaCO3/POE composite were the highest in the three groups of composites. The fire residue in the pyrolysis zone of the specimens increased corresponding to the increased flame-retardant volume fraction and with loading the nano-CaCO3 and POE, especially at low-flame-retardant concentration. The reinforcing and the flame-retarded mechanisms of the composites were discussed.

Synergistic effects of intumescent flame retardant and nano-CaCO3 on foamability and flame-retardant property of polypropylene composites foams

2017 ◽  
Vol 54 (3) ◽  
pp. 615-631 ◽  
Author(s):  
Li Depeng ◽  
Li Chixiang ◽  
Jiang Xiulei ◽  
Liu Tao ◽  
Zhao Ling
Keyword(s):  
Mechanical Properties ◽  
Stress Concentration ◽  
Flame Retardant ◽  
Synergistic Effects ◽  
Crystallization Rate ◽  
Intumescent Flame Retardant ◽  
Limit Oxygen Index ◽  
Scanning Calorimetry ◽  
Polypropylene Composites ◽  
Flame Retardant Property

Synergistic effects of intumescent flame retardant and nano-CaCO3 on foamability and flame retardant property of polypropylene composites and their foams were carefully investigated. The differential scanning calorimetry results showed that the intumescent flame retardant played a plasticizing effect on the polypropylene/intumescent flame-retardant composites and accelerated the crystallization rate. The rheological properties and supercritical CO2-assisted molding foaming behaviors of the polypropylene/intumescent flame retardant/nano-CaCO3 composites showed that the nano-CaCO3 could enhance their foamability. Scanning electron microscopy pictures and mechanical properties of the polypropylene/intumescent flame-retardant composites foams indicated that the agglomeration of intumescent flame retardant would reduce the cell uniformity and even cause the cell collapse. Furthermore, the stress concentration, caused by the agglomeration, could reduce the mechanical properties of the PP composites foams. The synergistic effect of the nano-CaCO3 could improve the cell uniformity and reduce the stress concentration so that the mechanical properties of the polypropylene/intumescent flame retardant /nano-CaCO3 composites foams were improved. Moreover, the polypropylene/intumescent flame retardant/nano-CaCO3 composites foams had the higher limit oxygen index values than the polypropylene/intumescent flame-retardant foams. TGA results also showed that the nano-CaCO3 could improve the thermal stability of the polypropylene composites foams by forming compact carbon layer. The experimental results indicated that the foamability of the polypropylene composites and the flame-retardant property of their foams could be improved by the synergistic effects of intumescent flame retardant and nano-CaCO3.

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