Fire Retardation through Polymer blends and Reduction of Heat Release Rates by the Charring Effect S. Crandel Fenton, Dr. Qingsheng Wang, Fazle Rabbi, Roshan Petal

Introduction The purpose of this study is to test the ability of various polymer blend coatings to reduce heat release rates for fire protection applications. This reduction in heat release rates is known as the charring effect. The charring effect is the response of a coating to increases in temperature that results in expansion and thereby a retardation of the spreading of heat (and flame). This charring effect is most often associated with metal coatings. However, this charring effect would be very beneficial if it could be used to protect wood used in structural applications. Characterization of the charring effect of various polymers will facilitate coating development. In addition to collecting data for individual polymers, a second long-term goal of this project will be an attempt to develop a mathematical model that is consistent with the data we collect. If such a mathematical model can be developed, then this will greatly reduce the materials costs associated with running large scale experiments with the polymers. I have participated in the early stage development of this project, which has largely involved learning how the conecalorimeter operates in preparation for polymer testing.

Polymer Research

Polymer blends of interest

The polymer research was focused on polystyrene, polypropylene, high density polyethylene (HDPE), and low density polyethylene (LDPE). The polymer blends that are of interest for our purposes are the blends that provide high percentage of reduction for the heat release rate as indicated from the graphs below. In these graphs, the vertical axes provides the blend compositions and the horizontal axes provide the range of reduction of the heat release rates.

PS: +30%RDP+5%clay, +10% of (75%)DPVPP clay +21%APP+7%CA PP: +20%IFR+4%MMT+2%C16 +40% MP +30% MP+ 10% PER +20% MP + 20% PER +10% MP + 30% PER +30% MP+ 10% DPER +20% MP + 20% DPER +30% MP+ 10% TPER +20% MP + 20%TPER +10% MP + 30% TPER +25% IFR + 5% HSO +18% APP+ 6% MA + 6% BCPPO +28% IFR+5% PP-g-MAH +28% IFR+5% PP-g-MAH+1.5% Organo clay HDPE: +40% MDH +45% MDH +50% MDH +55% MDH +45% MDH+5% EVA + 5% MMT +45% MDH+5% EVA + 5% OMMT LDPE: +40% ATH+10%Lauryl clay +50% ATH+10%Lauryl clay +60% ATH+10%Lauryl clay +60% MHSH +38% MHSH+ 2% MRP +33% MHSH+ 7% MRP +30% MHSH+ 10% MRP +25% MHSH+ 15% MRP

Instrument Design The cone calorimeter is designed to provide a consistent heat source to the sample being tested. The sample is placed in either the horizontal or vertical position and is set up for combustion, which is ignited by the spark igniter. The cone heater is what provides an uniform heat flux over the entire sample that makes the instrument so valuable to our research. The gas and soot is then pushed through the exhaust port to be further analyzed by respective sensors for each. These results are then relayed to the computer through computer software.

Experimental Design

Acknowledgements and Recognition I would like to thank Dr. Wang for allowing me to join his team. Fazle Rabbi conducted the polymer research. Roshan Petal conducted the inquiry in the mathematical model component of this project. Data included in the panels above were taken from many sources including: 1) Zheng, X, and Wilkie, C.A. (2003) Polymer Degradation and Stability 81, 539–550 2) Chigwada, G, and Wilkie, C.A. (2003) Polymer Degradation and Stability 80, 551–557 3) Yan, Y.-W., et al. (2012) Polymer Degradation and Stability 97, 1423-1431 4) Du, B., et al. (2009) Polymer Degradation and Stability 94, 1979–1985 5) Peng, H.-Q., et al. (2008) Journal of Industrial and Engineering Chemistry 14, 589–595 6) Chen, X. and Jiao, C. (2009) Fire Safety Journal 44, 1010–1014 7) Lv , P., et al. (2005) Polymer Degradation and Stability 90, 523-534 8) Tang, Y. (2003) Polym Int 52, 1396–1400 9) Lenza, J., et al. (2013) Polymer Degradation and Stability 97, 2581-2593 10) Zhang, G. and Wilkie, C. A. (2005) Polym. Adv. Technol. 16, 549–553 11) Lu, H., et al. (2004) Macromol. Mater. Eng. 289, 984–989

After identifying polymer blends of interest, those with high percentage reduction of heat release rates, we then determined the parameters that allowed for this high reduction of heat release rate. This step is ongoing. Our approach is both to identify data in the literature and replicate those results in our laboratory. Polymer blends with the greatest heat release reduction will then be applied to our samples, which will be evaluated using cone calorimeter.