Thermal degradation studies of different polar polyethylene copolymers

Abstract

ABSTRACT:The thermal degradation of different polar polyethylene copolymers, ethylene/methylacrylate (EMA), ethylene/ethylacrylate (EEA), ethylene/butylacrylate (EBA), ethylene/methylmethacrylate (EMMA), and ethylene/hydroxyethylmethacrylate (EHEMA), was studied by using thermogravimetric analysis (TGA), infrared analysis (FTIR), and size exclusion chromatography (SEC). Weight loss measurements of the different copolymers were performed at 333°C by using a nitrogen atmosphere in a TGA instrument. The samples thus aged were then characterized with the help of FTIR and SEC. Degradation reactions, such as ester pyrolysis, chain scission, and gelation, were investigated. EBA, EEA, and EHEMA undergo ester pyrolysis, which is affected by the structure of the ester moiety. EHEMA reacts additionally by transesterification and thus forms crosslinks. EMA and EMMA do not react by ester pyrolysis. It is concluded that the reaction products formed during ester pyrolysis support chain scission, and therefore, these reactions are observed more for EBA and EEA than for EMA and EMMA. Finally, the rate of chain scission is higher for EMMA than for EMA. This is explained as being due to an initiation of chain scission at the ␣-C-C bond, in which formed radicals are stabilized by the additional methyl group in EMMA.

Thermal and mechanical properties of polymer‐nanocomposites based on ethylene methyl acrylate and multiwalled carbon nanotube

“…Pure EMA starts to degrade in a nitrogen atmosphere at about 395°C and is completely degraded at about 448°C. The random scission of EMA (around 395–430°C) would be initiated by homolytic scission of a methoxycarbonyl side group followed by β scission rather than by main chain scission [51, 52]. The methoxycarbonyl side group makes the β CC scission easier due to its electronic and steric effects in EMA molecules [53].…”

Influence of the Structure of Acrylate Groups on the Flame Retardant Behavior of Ethylene Acrylate Copolymers Modified with Chalk and Silicone Elastomer

“…However, some acid formation was identified by IR measurements (thermally treated in air). Jäger et al [18] found a small amount of acid formation after treating EMA (5.7 mol%) in an N 2 atmosphere. This was mainly explained by traces of acrylic acid in the monomer, however, and not by decomposition of the polymer.…”

Study on adhesion strength, thermal creep resistance, and light transmittance of ethylene‐polypropylene copolymer grafted with silane for photovoltaic application

“…Other polymers have been explored to overcome this limit. Besides EVA, polar ethylene copolymers such as poly(ethylene‐ r ‐acrylic acid), polyvinylbutyral, ethylene(methylacrylate), ethylene(ethylacrylate), and ethylene(butylacrylate) have been investigated . Although these copolymers show somewhat higher thermal stability than EVA, they still display similar shortcomings to those of EVA originating from the polar side group.…”