Premium
Analysis of the types and amounts of carbonyl species present in oxidized polyethylene
Author(s) -
Benham John V.,
Pullukat Thomas J.
Publication year - 1976
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1976.070201210
Subject(s) - polyethylene , ketone , absorbance , chemistry , infrared spectroscopy , infrared , low density polyethylene , polymer chemistry , ethylene , analytical chemistry (journal) , organic chemistry , chromatography , catalysis , physics , optics
The carbonyl species present in oxidized polyethylene are qualitatively and quantitatively determined through the use of infrared measurements on the polymer. The method described makes use of a carbon monoxide/ethylene copolymer wedge in the reference beam of the infrared spectro photometer to compensate the large 1720 cm −1 ketone absorbance. This allows one to observe the 1710 cm −1 and 1735 cm −1 carbonyl absorbances as distinct peaks rather than as shoulders on the 1720 cm −1 peak. This is a significant advantage over other published infrared methods for this analysis. The absorbances obtained at 1710 cm −1 and 1735 −1 are then used in an equation to calculate the absorbance at 1720 cm −1 due to ketonic carbonyl only. Our results confirm Cooper and Prober's assignment of both the 1710 cm −1 and 1735 cm −1 absorbances in the infrared spectra of oxidized polyethylene to acid functionality. Our quantitative results are comparable to those reported by Cooper and Prober, and our method represents a significant reduction in the time required for the analysis (1.5 hr vs. ∼45 days). The carbonyl distribution in a commercially oxidized polyethylene wax was determined as being ∼11.0 ketone CO/2000 C and ∼21.7 acid CO/2000 C (with a σ of 1.8 CO/2000 C and 3.0 CO/2000, respectively). A high‐density polyethylene, oxidized with air in the laboratory, contained ∼1.91 ketone CO/2000 C and 2.19 acid CO/2000 C (with a σ of 0.08 CO/2000 C and 0.16 CO/2000 C, respectively).