Phenolic foam (PF) displays excellent flame, smoke, and toxicity (FST) properties and good insulation properties. Nevertheless, the friability and inferior mechanical properties of PF have critically restricted its application in many fields. A series of phenolic foam/silica nanocomposites (MPF) with different silica contents were synthesized by in situ polymerization in this study. During the in situ polymerization process, the synthesis of phenolic resin/silica nanocomposites and formation of chemical bonding between the components were generated simultaneously. The reactive principle between silica nanoparticles and prepolymer was investigated using Fourier transform infrared spectroscopy (FTIR), and the results of FTIR indicated existence of the chemical reaction between them. Meanwhile, silica can act as “bridge” to form crosslinked network structure. The mechanical, thermal, and friability properties of MPF nanocomposites were characterized. Moreover, the results of microstructure of pure PF and MPFs indicated that the cell size distributions of MPFs are narrower, the cell distributions of MPFs are more uniform, and the cell wall thickness of MPFs is thicker, compared with pure PF. When the content of silica sol was 2 wt%, the compressive strength, compressive modulus, and tensile strength were increased by a factor of 47.37%, 38.55%, and 57.14% compared with that of pure PF, respectively. Furthermore, all MPF nanocomposites exhibited better thermal stability and lower pulverization ratio than that of pure PF. POLYM. ENG. SCI., 2015. © 2015 Society of Plastics Engineers

Enhanced mechanical properties, thermal stability of phenolic-formaldehyde foam/silica nanocomposites via in situ polymerization

Flammability of two kinds of two extruded polystyrene foam was tested by micro-scale combustion calorimeter and cone calorimeter. Maximum specific heat release rate, specific heat release, heat release temperature, combustion time and fire growth rates from micro-scale combustion calorimeter tests, and time to ignition, effective net heat of combustion, heat release rate from cone calorimeter tests, were used to compare the flammability of two foams. These two methods would draw different results in evaluating flammability of the foams. This confliction is due to the test scale and combustion condition. The relationship between these two methods can be established with ignition temperature; thus, micro-scale combustion calorimeter can be used to predict time to ignition in cone calorimeter tests. Joint using of micro-scale combustion calorimeter and cone calorimeter leads to a comprehensive evaluation of flammability of polymers.

Compare the flammability of two extruded polystyrene foams with micro-scale combustion calorimeter and cone calorimeter tests

A review on cone calorimeter for assessment of flame-retarded polymer composites

SUMMARY

A series of experiments designed to characterize fire behavior on flat 1.2 m × 1.2 m samples of commercial non-fire-retarded flexible polyurethane foam were performed. Time-resolved heat release and mass loss rates were measured. Experimental parameters varied, including foam thickness (5.1 and 10.2 cm) and burning angle (+25°, +12.5°, 0°, −12.5°, and −25°). Polyurethane foam is typically produced by reacting a multifunctional isocyanate with a polyol. The foam used here was formed by reacting toluene diisocyanate and a polyol based on a condensed polyether of polypropylene oxide. Earlier cone calorimeter studies of this foam had revealed a clear two stage pyrolysis behavior in which the heated foam first released a gaseous fuel derived from the isocyanate component, while leaving behind a liquid produced primarily from the polyol, which only gasified and burned following additional heating. The subsequent burning behavior of the polyol-derived liquid is shown in this work to play a crucial role in the maximum heat release rate and total heat released by the fires spreading across the foam slabs. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Role of two stage pyrolysis in fire growth on flexible polyurethane foam slabs

Experimental investigations on the effects of bottom ventilation on the fire behavior of natural rubber latex foam

Two models that can be used to predict full-scale heat release rates of polyurethane foam slabs were evaluated in this study. Predictions were compared with results of furniture calorimeter tests of 10 cm thick polyurethane foam specimens which were ignited in the centre or on the edge. Furniture calorimeter results indicated that peak heat release rates and fire growth rates were higher during centre ignition tests than edge ignition tests. For both situations, the growth phase of the heat release rate curves measured in the full-scale tests was successfully predicted using t2 design fires; the choice of a specific t2 fire depended on the surface area of the specimen and ignition location. A model originally developed during the European Combustion Behaviour of Upholstered Furniture (CBUF) project was also evaluated using heat release rate data from cone calorimeter tests and flame area burning rates measured using infrared video records of the furniture calorimeter tests. This model was able to successfully predict the initial growth phase of the fires and predictions of peak heat release rates were within 17% of measured values. The model had less success in predicting heat release rates later in the growth phase and during the decay phase of the fires, and did not appear to capture all of the physics of the full-scale tests, in particular foam melting and subsequent liquid pool burning. As the model did show promise, future work is planned to address these shortcomings and to develop improved flame spread models for polyurethane foam.

Evaluating Models for Predicting Full-Scale Fire Behaviour of Polyurethane Foam Using Cone Calorimeter Data

Furniture calorimeter tests of polyurethane foam specimens were conducted to determine the effects of ignition location and specimen thickness on measured flame spread rates. These measurements were made using a new procedure that measured flame areas using infrared video records. Furniture calorimeter tests were conducted using specimens with thicknesses ranging between 2.5 cm and 10 cm, which were ignited in either the centre or on one edge. Flame spread rates increased with foam thickness, and flame spread rates in centre ignition tests were quicker than in edge ignition tests. These flame spread measurements will be used in a model, along with heat release rate data from cone calorimeter tests of the same foam, in order to predict heat release rates in furniture calorimeter tests of polyurethane foam slabs.

Effects of Thickness and Ignition Location on Flame Spread Rates in Furniture Calorimeter Tests of Polyurethane Foam

This is the peer reviewed version of the following article:

Robson LD, Torvi DA, Obach MR and Weckman EJ (2016). Effects of Variations in Incident Heat Flux When Using Cone Calorimeter Test Data for Prediction of Full-Scale Heat Release Rates of Polyurethane Foam. Fire and Materials, 40:89-113

which has been published in final form at https://doi.org/10.1002/fam.2271.


This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Us of Self-Archived Versions.

Matthew R. Obach

Papers

Evaluating Models for Predicting Full-Scale Fire Behaviour of Polyurethane Foam Using Cone Calorimeter Data

Effects of Thickness and Ignition Location on Flame Spread Rates in Furniture Calorimeter Tests of Polyurethane Foam

Effects of variations in incident heat flux when using cone calorimeter test data for prediction of full-scale heat release rates of polyurethane foam