Self-Extinguishing Polymer Nanocomposites
- PDF / 5,909,929 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 20 Downloads / 293 Views
EE13.52.1
Self-Extinguishing Polymer Nanocomposites Mayu Si1, Hsinchou Chu1, Daniel Hefter2, Aryeh Sokolov3, Jonathan Hefter4, Michael Smith5, Jonathan Sokolov1, Miriam Rafailovich1 1 Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, NY 11794 2 DRS High School, Woodmere, NY 11598 3 HAFTR High School, Cedarhurst, NY 11516 4 University of Pennsylvania, Philadelphia, PA 19104 5 Fire Science Division, NIST, Gaithersburg, MD 20899 ABSTRACT Self-extinguishing PMMA/Clay nanocomposites with conventional flame retardant agents, decabromodiphenyl oxide (DB) and antimony trioxide (AO) have been prepared by melt blending using Brabender. The combustion behavior was first investigated by subjecting slabs of the polymer to UL-94 V0 testing. We found that the polymers with only the retardant agents or the clay could not pass. On the other hand all polymers with both components were selfextinguishing. DMA results show that the introduction of 5 wt% clay improves PMMA bending modulus by 28 % and increases Tg by 8 °C. the addition of clay can effectively avoid dripping during burning test. Based on the cone calorimeter data, the general mechanism is proposed that the synergy between the char formation promoted by the clay in condense phase and free radical capture in gas phase due to the DB and AO makes the material become self-extinguishing.
INTRODUCTION Very few polymers are currently self-extinguishing when exposed to a flame. Since polymers ignite easily, the combustion process can be retarded through compounding with conventional flame retardant (FR) agents such as, halogen, phosphorus and inorganic materials [1]. The efficacy of these compounds depends on the ability to disperse them within the polymer. Since they are generally immiscible with most materials, very few polymers can be rendered “selfextinguishing” according to the stringent UL-V0 designation. In recent years, polymer/organoclay nanocomposites have attracted intense interest due to the comparatively greater strength, modulus, heat resistance, decreased gas permeability and flammability than pure polymer and conventional composites [2]. The addition of small amount of organoclay (normally < 10 wt%) can greatly improve the flame retardancy of original polymer, such as remarkable decreasing heat release rate and mass loss rate, due to the char formation promoted by the clay. But clay itself can not make the polymeric materials self-extinguish, which is the biggest issue in polymer flame retardancy industry. Base on the clay as a potential flame retardant agent and a compatibilizer that can improve the dispersion of FR agents in polymer matrix [3], a novel idea was proposed by combining clay and traditional FR agents, which can effectively improve flame retardancy and reduce the amount of FR agents. In this paper, PMMA was melt blended with clay, decabromodiphenyl oxide (DB) and antimony trioxide (AO). The fire performance was evaluated by UL 94 V0. Cone calorimeter was used to characterize the flame retardanc
Data Loading...
