N-Nitrosamine low compounding of EPDM
ing. C.J.J. Krans, DSM Elastomers Europe
This presentation gives an overview of the long history of DSM's experience with the N-Nitrosamine problem. DSM Elastomers, a major worldwide producer of elastomers, has conducted some in-depth investigations into the possibility of N-Nitrosamine safe compounding of EPDM. The results of these investigations are dealt with in this paper/lecture.
The following topics will be covered:
*Measurements of N-Nitrosamines of various EPDM compounds
*A comparison of different accelerator systems
*Vulcanisation and vulcanisate properties with N-Nitrosamine safe accelerators
*Further ways to reduce N-Nitrosamine emissions
In EPDM compounds the main source of secondary amines which can form N-Nitrosamines, are the accelerators. In this lecture it will be pointed out that only minor quantities of secondary amines can emit substantial amounts of N-Nitrosamines. After establishing the group of accelerators which do not form any N-N-Nitrosamines, this 'new' group of accelerators is studied intensively.
The vulcanisation and vulcanisate properties of compounds is discussed using various accelerators for conventional and semi-efficient compounds. The N-Nitrosamine safe accelerators are compared to secondary amine accelerators. DSM succeeded in changing secondary amine accelerator systems into N-Nitrosamine safe accelerator systems. Practical examples will be presented and suggestions how to modify these systems for vour specific use.
Alternative ways to reduce the amount of N-Nitrosamines emitted during processing, is the last item which will be discussed.