Premium
Comparative effects of cobalt carboxylates on the thermo‐oxidative degradation of LDPE films
Author(s) -
Roy P. K.,
Surekha P.,
Rajagopal C.,
Choudhary V.
Publication year - 2006
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.25460
Subject(s) - low density polyethylene , cobalt , stearate , polyethylene , materials science , fourier transform infrared spectroscopy , melt flow index , degradation (telecommunications) , polymer chemistry , high density polyethylene , ultimate tensile strength , chemical engineering , nuclear chemistry , copolymer , chemistry , composite material , polymer , metallurgy , telecommunications , computer science , engineering
This article reports the effect of three cobalt carboxylates—cobalt stearate (CoSt 3 ), cobalt palmitate (CoPal 3 ), and cobalt laurate (CoLau 3 )—on the thermo‐oxidative degradation of low‐density polyethylene (LDPE) films prepared by sheeting process. The carboxylates were blended with LDPE in the concentration range of 0.05–0.2% (w/w). The degradation was monitored by techniques such as FTIR spectroscopy, change in the mechanical properties (tensile strength and elongation at break), viscometry, surface electron microscopy, melt flow index measurements, and apparent density measurements. Studies indicate that films containing these additives are highly susceptible to thermo‐oxidative degradation. Oxygen containing functionalities such as carbonyl and vinyl species are generated on the surface of polyethylene because of thermo‐oxidation, as indicated by FTIR studies. This oxidative process is accelerated in the presence of cobalt carboxylates. The degradation of LDPE was found to increase proportionally with concentration as well as with increasing chain length of the cobalt carboxylate, and follow the order CoSt 3 > CoPal 3 > CoLau 3 . © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3758–3765, 2007