English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Commercial fibers covered with poly(dimethylsiloxane) were used to pre-concentrate (solid phase microextraction technique) products evolved from the thermal degradation of isotactic polypropylene. Although the analysis by GC-MS indicated the formation of more than one hundred evolved products (ca. forty were identified), only twenty nine formed at 470°C (the temperature of maximum degradation rate for isotactic polypropylene) were analyzed. The main compounds identified were 2,4-dimethyl-1-heptene, 2-methyl-1-pentene, 2,3-dimethyl hexane, n-pentane and 1,3,5-trimethyl cyclohexane. The analysis at 470°C, using different degradation times, also indicated that the compounds 2-methyl-1-pentene and 2,4- dimethyl-1-heptene (major products) were formed at 15 and 25 minutes, respectively. The mechanism proposed for the formation of the major compounds was based on radical formation through chain cleavage (allyl and secondary radicals), followed by a chain decomposition process via hydrogen radical addition or cyclization to a thermodynamically stable six-membered ring.

e-polymers

Use of the SPME-GC-MS technique to study the thermal degradation of isotactic polypropylene: Effects of temperature and reaction time, and analysis of the reaction mechanism