The thermal degradation of poly(iso-butyl methacrylate) and poly(sec-butyl methacrylate)

Abstract

The non-oxidative thermal degradation of poly(iso-butyl methacrylate) and poly(sec-butyl methacrylate) was investigated by studying changes in the polymer residue. Due to the different number of β-hydrogens in their ester substituents, these two polymeric isomers behave differently when subjected to elevated temperatures. Poly(iso-butyl methacrylate) degrades quantitatively by depolymerisation with zip lengths of the same order of magnitude as those of poly(methyl methacrylate). Poly(sec-butyl methacrylate) degrades by a combined degradation mechanism of depolymerisation and de-esterification. De-esterification becomes a significant thermolysis route at temperatures higher than 240 ºC. .

Neoksidativna termička degradacija poli(iso-butil metakrilata) i poli(sec-butil metakrilata) ispitana je praćenjem promena u polimernom ostatku. Zbog različitog broja β-vodonika u estarskom supstituentu, ova dva polimerna izomera se različito ponašaju prilikom izlaganja povišenim temperaturama. Poli(iso-butil metakrilat) degradira kvantitativno depolimerizacijom do svog monomera sa kinetičkim dužinama depropagacije istog reda veličine kao kod degradacije poli(metil metakrilata). Poli(sec-butil metakrilat) degradira kombinovanim mehanizmom degradacije: depolimerizacijom i deesterifikacijom. Deestirifikacija postaje značajna reakcija termolize na temperaturama višim od 240 ºC. .