Extraction and Quantitation of Polyolefin Additives

Abstract

The extraction and subsequent separation and quantitation of polymer additives in polyolefins has proven to be a challenge for the analytical chemist. There have been several workers over the years who have investigated the separation of additives in polyolefins (1–7), but the extraction and recovery (at > 90%) in reasonable times has been most difficult. the Soxhlet extraction technique has been used for many years, but suffers in that it takes over twelve hours to extract most of the additives used in polyolefin formulations. Some workers have used the ultrasonic bath (7), but not very much work has been done with the microwave oven. We have investigated some ways to extract the additives from polyolefins, namely, microphye oven and ultrasonic bath techniques for high density polyethylene (HDPE), low density polyethylene (LDPE), and polypropylene. We have concentrated on identifying and quantitating recoveries for typical polyolefin

antioxidants, 20 such as Irganox 1010, Irgafors 68, and Cyasorb UV 531. the extraction times are typically 20 minutes for the microwave oven and 30–60 minutes for the ultrasonic bath with 90+% recoveries being obtained. Both normal phase isocratic (used when phosphites are present) and reverse phase gradient LC techniques are discussed. We have also extracted the slip agent, erucamide, from LDPE, using reverse phase, at 200nm.