Analysis of pyrolysis products of ethylene-vinyl acetate coploymer (EVA) using pre-deacetylation

- Deacetylation step was introduced to remove acetic acid.
- Major pyrolysis products of the deacetylated EVA were n-alkanes, 1-alkenes, α,ω-alkadienes, and ring compounds.
- The ring compounds are formed from the ethylene-vinyl acetate (VA) heterosequences.
- Butadiene is formed from the one CC bond sequence, while 4-vinlycyclohexene is formed from the ethylene-VA sequence.

Of pyrolysis products formed from of poly(ethylene-co-vinyl acetate) (EVA), acetic acid is the most abundant species. When EVA was pyrolyzed without pre-pyrolysis step, broad acetic acid peak covered some pyrolysis product peaks in the chromatogram. Deacetylation step was introduced to remove acetic acid, and the optimal deacetylation condition was pre-pyrolysis at 400 °C for 10 min. Pyrolysis products formed from the deacetylated EVA were separated using gas chromatograph/mass spectrometer (GC/MS) equipped with PLOT column. Major pyrolysis products of the deacetylated EVA were n-alkanes, 1-alkenes, α,ω-alkadienes, and ring compounds. The n-alkanes, 1-alkenes, and α,ω-alkadienes are mainly generated from the ethylene homosequence, while the ring compounds are formed from the ethylene-vinyl acetate (VA) heterosequences. 1,3-Butadiene is formed from the one CC double bond sequence, while 4-vinlycyclohexene is formed from the ethylene-VA alternating sequence.