Flame-Retardancy Properties of Intumescent Ammonium Poly(Phosphate) and Mineral Filler Magnesium Hydroxide in Combination with Graphene

Polymers

Bettina Dittrich²  Karen-Alessa Wartig¹  Rolf Mülhaupt¹  Bernhard Schartel² 

[1] Freiburg Materials Research Center and Institute for Macromolecular Chemistry, Albert-Ludwigs-University of Freiburg, Stefan-Meier-Str. 31, Freiburg 79104, Germany; E-Mails:;BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, Berlin 12205, Germany; E-Mail:

关键词: graphene;    intumescence;    ammonium polyphosphate;    magnesium hydroxide;    synergy;    polypropylene;   

DOI  :  10.3390/polym6112875

来源: mdpi

【 摘 要 】

Thermally reduced graphite oxide (TRGO), containing only four single carbon layers on average, was combined with ammonium polyphosphate (APP) and magnesium hydroxide (MH), respectively, in polypropylene (PP). The nanoparticle’s influence on different flame-retarding systems and possible synergisms in pyrolysis, reaction to small flame, fire behavior and mechanical properties were determined. TRGO has a positive effect on the yield stress, which is decreased by both flame-retardants and acts as a synergist with regard to Young’s modulus. The applicability and effects of TRGO as an adjuvant in combination with conventional flame-retardants depends strongly on the particular flame-retardancy mechanism. In the intumescent system, even small concentrations of TRGO change the viscosity of the pyrolysing melt crucially. In case of oxygen index (OI) and UL 94 test, the addition of increasing amounts of TRGO to PP/APP had a negative impact on the oxygen index and the UL 94 classification. Nevertheless, systems with only low amounts (≤1 wt%) of TRGO achieved V-0 classification in the UL 94 test and high oxygen indices (>31 vol%). TRGO strengthens the residue structure of MH and therefore functions as a strong synergist in terms of OI and UL 94 classification (from HB to V-0).

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.