The Influence of Polymer Morphology on the Combustion of Melamine Filled Flexible Foams

Abstract

The combustion of flexible polyurethane foams is drawing in creasing interest from regulators, fire fighters, and the public around the world. Recent legislation in the United Kindgom has banned the use of conven tional foam for residential furnishings. Regulations based on the British Standard 5852 Part 2 have resulted in the production of foams filled with melamine as a means of meeting the test protocols by dramatically altering the combustion behavior of foam. As part of a continuing effort to understand the role of polymer morphology on foam combustion, we have evaluated the role played by a series of foam parameters on the combustion test results of foams made without and with melamine. We have examined the relative importance of increased polyarylureas which result from high water levels in foam for mulations and the decreased foam density. Density changes made by incorpora tion of blowing agents separate the effects of changes in surface area from chang ing polyarylurea content. The results of modified British Standard 5852 part 2 source 5 testing indicate that weight loss values for melamine filled foams are density dependent at low foam density but relatively density independent above some level which will be formulation dependent. The Downward Vertical Burn Test is unable to predict foam pass or fail in the BS 5852 test, but can sep arate the melamine filled foams from unfilled foams on the basis of burn rate analysis. The Ohio State University calorimeter burn test results indicate den sity dominates trends in combustion over polymer morphology. Correlations between slope E and performance in the BS 5852 test indicate the importance of time to maximum heat release as well as maximum rate of heat release for passing the weight loss criteria.