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Stabilization of low density polyethylene with sterically hindered derivatives of 4‐hydroxybenzoic acid
Author(s) -
Seiffarth K.,
Baeseler M.,
Dahlmann J.
Publication year - 1989
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19890270114
Subject(s) - steric effects , low density polyethylene , benzophenone , stabilizer (aeronautics) , chemistry , polyethylene , benzoic acid , organic chemistry , benzoates , polymer chemistry , mechanical engineering , engineering
In comparison with other commercial light stabilizers, sterically hindered 4‐hydroxybenzoates are found to possess only a weak power, if they are used for low density polyethylene (LDPE). It is known that these benzoates exhibit significant synergistic effects together with 2‐hydroxybenzophenones and hindered amine light stabilizers in light stabilization of high‐density and linear low‐density polyethylene. The light stabilizing efficiencies of the above mentioned stabilizers and mixtures of them in different weight ratios are determined by weathering in a Xenotest 150 unit. Only small synergistic effects of about 15 −30% are found for light stabilizing LDPE. The effects can be explained by the stabilizing efficiency of sterically hindered 4‐hydroxybenzoates during processing. Combining of light stabilizing structure components like 2‐hydroxy‐benzophenone resp. 2, 2, 6, 6‐tetramethylpiperidine with sterically hindered 4‐hydroxybenzoates in one stabilizer molecule only, from the first mentioned combination, results a powerful light stabilizer. Its efficiency is the sum of the powers of the single structure components.