Introduction

With their ease of processing and high performance, polymeric materials have become a common and important part of modern life. However, because almost all polymers are composed predominately of hydrocarbons, these materials are flammable and thus greatly increase fire hazard to human life and property. As estimated for the United States, there are approximately 400,000 residential fires each year, 20% involving electrical distribution and appliances, and 10% concerning upholstered furniture and mattresses. These fires kill about 4,000 people, injure 20,000 people, and result in property losses amounting to about US$4.5 billion. Flame retardants are additives that can make flammable materials more difficult to ignite and significantly reduce the spread of fire. Use of flame retardants plays a major role in fire safety, saving lives, and preventing injuries and property damage. For example, in 1974, the number of recorded television set fires in the United Kingdom was more than 2,300, whereas this number had decreased to 470 in 1989, despite the number of television sets in use increasing many times. This is because effective flame retardants were developed for television sets.