Reactive extrusion processing free-radical grafting reactions

As mentioned above, controlled degradation of polypropylene was one of the earliest reactive extrusion technologies developed. A fairly substantial literature on the subject has appeared in the past 15 years. The mechanism of free radical attack of the polymer backbone is now thought to be well known (3-6). The following sequence of free radical reactions in the extruder provide a summary of key process steps involved in grafting functional groups onto chains of the polypropylene molecules. 

---