Introduction

Reinforced thermosetting resins are one of the faster growing segments of a rapidly expanding plastics industry. This growth will create vast needs for operating personnel, resulting in an increased burden of training these new people in the safety aspects of the industry. In addition, there has been an intensified emphasis on ecology, health, and safety, accompanied by ever tighter legislation, so that even veterans in the industry will profit from the information contained in this bulletin.

In their function as free radical initiators (catalysts) organic peroxides are essential components in the manufacture of reinforced plastics. Small amounts, mixed with resins and decomposed by means of heat or promoters, produce active fragments (radicals) which initiate resin polymerization. The resin polymerization occurs in combination with the various reinforcing materials (such as glass cloth) to produce thermosetting products having the required properties.

The ability of very small amounts of organic peroxides to produce active radicals sufficient for complete polymerization should emphasize the importance of proper procedures in handling and storing the commercial concentrated forms of these peroxides.

Failure to observe these procedures can lead to poor product performance and quality and, in some instances extremely hazardous conditions. Various peroxide formulations or products differ from each other in the hazard potential of their decomposition and, hence, in their handling requirements.

Only the kinds commonly used in RP manufacture will be covered.