Failure Analysis of Rubber Materials Using Pyrolysis Gas Chromatography/Mass-Spectrometry and Nitrogen Phosphorus Detector(PY-GC/MS/NPD)

摘要

Subtle differences in rubber formulations are common,but they rarely influence the overall performance of the final product.However,there are instances where the product will’suddenly’be more brittle,easily deformed or fail in routine use.When this occurs,the search for differences begins.Detailed analyses of the”good”and”bad”rubbers will often reveal differences in the additive package,the presence of unwanted contaminants or unexpected chemical linkages.Frontier Lab has developed a method map that guides the analyst through the maze of GC analytical techniques used to characterize the rubber materials and perform failure analysis.In this study,two rubber pump diaphragms are used to demonstrate how the method map using the multi-shot pyrolyzer enables an analyst to quickly and efficiently characterize rubber materials.The”Good”sample lasted>1200 hours before failure while the”Bad”sample lasted<800 hours before failure.Failure was defined when the diaphragm cracked and ceased to function.The question being asked is:”These two rubber samples perform differently;is there a difference in the chemical composition of the two samples?”To answer this question,Pyrolysis technique with Gas Chromatography-Mass Spectrometry,as well as Nitrogen Phosphorus Detector will be used.Multiple pyrolyzer modes,such as Evolved Gas Analysis(EGA)and Heart Cutting(HC)analyses will be performed to characterize the differences between the two rubber samples.In addition,a novel approach of using a Pyrolyzer as the sample introduction technique followed by simultaneous data acquisition by multiple GC detectors(MS/NPD)will be demonstrated.