Strukturuntersuchung von polyestern durch direkten abbau im massenspektrometer, 3. Poly‐β‐propiolacton, poly‐β‐pivalolacton und poly‐δ‐valerolacton

Abstract

Poly(oxycarbonylethy1ene) (poly-B-propiolactone), poly(oxycarbony1-1,l-dimethylethylene) (poly-Bpivalolactone), and poly(oxycarbonyltetramethy1ene) (poly-6-valerolactone) were pyrolyzed directly in the ion source of a mass spectrometer and their thermal and electron impact induced degradation mechanisms are established. Poly-B-propiolactone is thermally degraded by rupture of the O-CH2-bond by a cis elimination to give carboxyl and acryloyl endgroups, whereas poly-6-valerolactone depolymerizes to 6-valerolactone. Poly-8-pivalolactone degrades thermally to cyclic oligomers of pivalolactone, which could be proved by a separated pyrolysis and IR-spectroscopy and gel chromatography. EinleitungUber die thermischen Abbaureaktionen einiger Polyester wurde bereits mehrfach berichtet' -'). So beschrieben Gresham et a].'), daS sie beim Erhitzen von Poly-8-propiolacton auf 200°C

Thermal Properties and Non-Isothermal Crystallization Kinetics of Poly (δ-Valerolactone) and Poly (δ-Valerolactone)/Titanium Dioxide Nanocomposites

“…In contrast to poly (δ-caprolactone) and poly(L-lactic acid), which are linear aliphatic polyesters, only a few investigations on the degradation behavior of PDVL have been reported [71,72]. In this work, the thermal degradation of pure PDVL and PDVL/TiO 2 nanocomposites was performed by the TGA method, and the thermograms obtained in nitrogen gas atmosphere are grouped in Figure 14.…”

Thermal Degradation of Environmentally Degradable Poly(hydroxyalkanoic acid)s

“…In contrast to PLLA and PCL, there have been few reports on the thermal degradation behaviors of PVL. [17,56] Figure 10. TIC of Py-GC/MS of P(4HB) at various temperatures (A) and relative mass spectra of P(4HB) pyrolysis products (B).…”

“…PVL is a linear aliphatic polyester with five carbons in the monomeric main chain and can be synthesized by a ring‐opening polymerization of δ ‐valerolactone ( δ ‐VL). In contrast to PLLA and PCL, there have been few reports on the thermal degradation behaviors of PVL 17,56…”

Preparation and characterization of double‐layered microencapsulated red phosphorus and its flame retardance in poly(lactic acid)

“…A first order kinetics analysis gives its activation energy E A = 261.5 kJ mol −1 for the weight loss peak (weight loss 5–95%). The thermal decomposition of PLA is very complicated and much research work has been done about it 28, 29. Generally speaking, based upon a hydroxyl end‐initiated ester interchange process giving cyclic oligomers, lactide, acetaldehyde, and carbon monoxide at low temperature, PLA will further degrade by an electron impact‐induced mechanism by elimination of the same products and also CO 2 and methylketene as well as other fragments at higher temperature.…”