This book deals with the most important substances used as additives in the plastics industry to improve the properties of polymer-based materials. Each chapter deals with a particular type of additive based on the type's definition, structure, and classification according to main effects on polymeric materials. The mechanism of the additive efficiency and its effects on basic properties of specific polymers are discussed and a survey of its important qualities and practical applications is given. Each chapter is introduced by a theoretical analysis of the practical and technological importance of the ad- ditive. The book is mainly intended for students in technical colleges, polytechnics and universities who are studying plastics technology and macromolecular chemistry as part of their general curriculum and for technologists in industry engaged in development, sales, technical service and production functions, and applications of plastics. An elementary knowledge of chemistry, physical chemistry and polymer science at the technical college level is assumed. Prague and Montreal, December 1982 J. Stepek, H. Daoust Table of Contents Introduction .