Premium
The characterization of short chain branching in polyethylene using fourier transform infrared spectroscopy
Author(s) -
Blitz Jonathan P.,
McFaddin Douglas C.
Publication year - 1994
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.1994.070510102
Subject(s) - fourier transform infrared spectroscopy , branching (polymer chemistry) , linear low density polyethylene , spectroscopy , infrared spectroscopy , materials science , polyethylene , polymer chemistry , absorbance , analytical chemistry (journal) , fourier transform , infrared , chemistry , organic chemistry , chromatography , mathematics , composite material , optics , physics , mathematical analysis , quantum mechanics
The characterization of short chain branching in polyethylene using transmission FTIR spectroscopy is investigated. Traditional methodologies, using the methyl deformation band for qualitative and quantitative analyses, have recognized shortcomings. The methyl and methylene rocking bands, which are more characteristic of short chain branch type, were found to be more useful. Methyl, ethyl, butyl, isobutyl, and hexyl branches are qualitatively and quantitatively characterized in LLDPE copolymers by FTIR spectroscopy. Methyl branches were characterized by an absorbance at 935 cm −1 , ethyl branches at 770 cm −1 , butyl branches at 893 cm −1 , isobutyl branches at 920 cm −1 , and hexyl branches at 888 cm −1 . Fourier self‐deconvolution was used to resolve overlapping bands for ethyl, butyl, and isobutyl branches. Using calibrations derived for LLDPE copolymers from 13 C NMR data, FTIR spectroscopy was also used to characterize LLDPE terpolymers and LDPE resins. The FTIR and NMR data are in qualitative and quantitative agreement. In some cases correction were made to the FTIR results using data obtained from the methyl deformation band. The FTIR technique is less costly and faster than NMR spectroscopy. © 1994 John Wiley & Sons, Inc.