Thermo-Mechanical Behavior of Polymer Composites Exposed to Fire

Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University

pdf format of this dissertation

ABSTRACT
One of the most critical issues for Polymer Matrix Composites (PMCs) in naval applications is the structural performance of composites at high temperature such as that experienced in a fire. A three-dimensional model including the effect of orthotropic viscoelasticity and decomposition is developed to predict the thermo-mechanical behavior and compressive failure of polymer matrix composites (PMCs) subjected to heat and compressive load. An overlaid element technique is proposed for incorporating the model into commercial finite element software ABAQUS. The technique is employed with the user subroutines to provide practicing engineers a convenient tool to perform analysis and design studies on composite materials subjected to combined fire exposure and mechanical loading.
The resulting code is verified and validated by comparing its results with other numerical results and experimentally measured data from the one-sided heating of composites at small (coupon) scale and intermediate scale. The good agreement obtained indicates the capability of the model to predict material behavior for different composite material systems with different fiber stacking sequences, different sample sizes, and different combined thermo-mechanical loadings.
In addition, an experimental technique utilizing Vacuum Assisted Resin Transfer Molding (VARTM) is developed to manufacture PMCs with a hypodermic needle inserted for internal pressure measurement. One-sided heating tests are conducted on the glass/vinyl ester composites to measure the pressure at different locations through thickness during the decomposition process. The model is employed to simulate the heating process and predict the internal pressure due to the matrix decomposition. Both predicted and measured results indicate that the range of the internal pressure peak in the
designed test is around 1.1-1.3 atmosphere pressure. Download pdf formatn and read more

A review of fire blocking technologies for soft furnishings

A review by Shonali Nazaré and Rick D Davis

       Download this review,  pdf document, click here

Pinfa Newsletter N°44

Pinfa Newsletter N°44 , August edition is now available, click here.

Flame Retardant markets to 2018

Please find here a new document about “Flame Retardant markets to 2018” : PDF

Source: Roskill

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Component ratio effects of hyperbranched triazine compound and APP in flame-retardant polypropylene composites

This article was published in Journal of Applied Polymer Science, 3 JUN 2014.

ABSTRACT

A hyperbranched derivative of triazine group (EA) was synthesized by elimination reaction between ethylenediamine and cyanuric chloride. The different-mass-ratio EA and ammonium polyphosphate (APP) were mixed and blended with polypropylene (PP) in a constant amount (25%) to prepare a series of EA/APP/PP composites. The component ratio effect of EA/APP on the flame-retardant property of the EA/APP/PP composites was investigated using the limiting oxygen index (LOI), vertical burning (UL-94), and cone calorimetry tests. Results indicated that the EA/APP/PP (7.50/17.50/75.00) composite with the appropriate EA/APP mass ratio had the highest LOI, UL94 V-0 rating, lowest heat release rate, and highest residue yield.

These results implied that the appropriate EA/APP mass ratio formed a better intumescent flame-retardant system and adequately exerted their synergistic effects. Furthermore, average effective combustion heat values revealed that EA/APP flame retardant possessed the gaseous-phase flame-retardant effect on PP. Residues of the EA/APP/PP composites were also investigated by scanning electron microscopy, Fourier-transform infrared, and X-ray photoelectron spectroscopy. Results demonstrated that the appropriate EA/APP mass ratio can fully interact and lock more chemical constituents containing carbon and nitrogen in the residue, thereby resulting in the formation of a dense, compact, and intumescent char layer. This char layer exerted a condensed-phase flame-retardant effect on EA/APP/PP composites. Read more : click here

Predicting SBI test results on the basis of cone calorimeter data

The most important Euroclass test method for products with a non-negligible contribution to fire is the Single Burning Item (SBI) test. Correlation between the results of the SBI test and the cone calorimeter is an issue of great interest. The cone calorimeter is a well-established and acknowledged test method, and it requires only a small amount of specimen material. Even though the official classification of products in Europe is made on the basis of the SBI test results, the cone calorimeter can be a useful tool for product development and quality control. Several modelling approaches on the prediction of heat release and classification in the SBI test have been published. Many models predict well the performance of untreated wood products in the SBI tests, but fire retardant treated wood has proven problematic in several cases. An application of a model, developed especially for fire retardant treated wood products, is presented below… Read more: click here

Polymer Green Flame Retardants, 1st Edition

Author: Constantine Papaspyrides

Description

 Polymer Green Flame Retardants covers key issues regarding the response of polymers during fire, the mechanisms of their flame retardation, the regulations imposed on their use, and the health hazards arising from their combustion. Presenting the latest research developments, the book focuses in particular on nanocomposites, believed to be the most promising approach for producing physically superior materials with low flammability and ecological impact. The fire properties of nanocomposites of various matrixes and fillers are discussed, the toxicological characteristics of these materials are analyzed, addressing also their environmental sustainability.

Edited by distinguished scientists, including an array of international industry and academia experts, this book will appeal to chemical, mechanical, environmental, material and process engineers, upper-level undergraduate and graduate students in these disciplines, and generally to researchers developing commercially attractive and environmentally friendly fire-proof products.

9780444538086

Infrared camera – a promising tool in fire testing and fire research

This article was published in Brandposten n°49.

ANDREAS GAGNAT BOE
andreas.boe@sintef.no@sintef.no

Infrared cameras detect energy in the form of infrared radiation from hot bodies and create a thermal image of the temperature differences. The technology is currently used for many different applications and has in recent years increasingly been used in fire prevention measures. Among other things, infrared cameras contribute to improving fire safety in tunnels, including the Mont Blanc tunnel and the Bjørvika tunnel in Oslo, in that they can detect a fire much earlier than ordinary surveillance cameras.

SINTEF NBL has an infrared camera of type FLIR GF-309. The camera measures temperatures from -40 °C til 1500 °C, it “sees” through smoke and flames and provides useful supplemental information in fire tests and to fire research. The infrared camera provides visualization of temperature distribution on the surface of a specimen, and thermal video sequences show the temperature distribution changes with time. The sensitive optics of FLIR GF-309 can detect temperature differences of less than 25mK.

Applications for the infrared camera in fire testing and fire research

Finding the “hot spots”

Our infrared camera can be used to visualize and detect so called “hot spots”, i.e. areas of a  specimen that reaches substantially higher temperatures than the rest of the specimen, during exposure to a fire. Figure 1 is a good illustration of this. Here, the fire resistance of a non load-bearing wall with steel beams and to layers of ordinary plaster on each side is tested in a vertical furnace. The infrared image clearly shows areas where the surface of the wall has elevated temperatures.

The temperature of the “hot spots” can be extracted by analyzing the infrared pictures, either directly during the test or afterwards. This way it is possible to ensure that the hottest areas actually are the ones that are analysed, as opposed to using thermocouples, where the measuring points are predefined before the test. Detecting the local temperature growth is useful for anyone who

develops products and structures that are meant to resist fire. Areas that are particularly exposed to heat can be detected and thus improved in further product development. This is useful information for most product types, for example for passive fire protection, pipes, panels, fire doors, walls,  windows, and especially for products with potential weaknesses such as joints and connections… Read more:  click here (page 24)

 

Innovative and Sustainable Flame Retardants in Building and Construction

Building products need to meet a variety of performance requirements. Although there are few fire performance requirements for building products in one-family dwellings, such requirements are significant for commercial, industrial, and multi-family buildings. Depending on the type of materials and intended application, specific fire performance properties of building materials are tested by use of different test methods. When designing a building a very important consideration is how it will behave in fire and ensure the elements of structure will not collapse but remain standing or hold back the fire for a prescribed time. The building regulations stipulate the rules and the degree of fire resistance of the elements of structure. Read more: click here

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Source: Pinfa

An Alternatives Assessment for the Flame Retardant DecaBDE-FINAL REPORT/January 2014

Download pdf document here : Report

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