An efficient mono-component polymeric intumescent flame retardant for polypropylene: preparation and application
Zhu-Bao Shao1, Cong Deng, Yi Tan
1Center for Degradable and Flame-Retardant Polymeric Materials, College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Analytical and Testing Center, Sichuan University , Chengdu 610064, China.
ACS Applied Materials & Interfaces
|April 19, 2014
Summary
A new piperazine-modified ammonium polyphosphate (PA-APP) significantly enhances polypropylene flame retardancy. This novel material improves oxygen index and passes stringent vertical burning tests, offering superior fire protection.
Area of Science:
- Polymer Science
- Materials Science
- Flame Retardancy
Background:
- Previous studies showed limited flame-retardant efficiency of ethylenediamine- or ethanolamine-modified ammonium polyphosphates in polypropylene.
- A need exists for more effective intumescent flame retardants for polymers.
Purpose of the Study:
- To synthesize and evaluate a novel mono-component polymeric intumescent flame retardant, piperazine-modified ammonium polyphosphate (PA-APP).
- To assess the flame-retardant performance of PA-APP in polypropylene composites.
- To investigate the flame-retardant mechanism of PA-APP.
Main Methods:
- Synthesis of piperazine-modified ammonium polyphosphate (PA-APP).
- Incorporation of PA-APP into polypropylene (PP) to create PP/PA-APP composites.
- Evaluation of flame retardancy using oxygen index, UL-94 vertical burning tests, and cone calorimetry (CC).
- Analysis of flame-retardant mechanism using Fourier transform infrared spectroscopy (FTIR).
Main Results:
- PP containing 22 wt% PA-APP achieved an oxygen index of 31.2% (58.4% increase vs. APP) and passed UL-94 V-0 rating.
- PP/PA-APP composites showed superior performance in cone calorimetry compared to PP/APP composites.
- For PP with 25 wt% PA-APP, peak fire growth rate (FGR) and smoke production rate (SPR) decreased by 86.4% and 78.2%, respectively, compared to PP/APP.
Conclusions:
- Piperazine-modified ammonium polyphosphate (PA-APP) is a highly efficient mono-component polymeric flame retardant for polypropylene.
- The P-N-C structure formed during PA-APP decomposition promotes a stable char layer, enhancing flame retardancy.
- PA-APP offers significantly improved fire safety performance compared to unmodified ammonium polyphosphate.
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