Characterization of Thermal Degradation of Polytrimethylene Terephthalate by MALDI-TOF Mass Spectrometry

Abstract

The thermal degradation products of polytrimethylene terephthalate (PTT) obtained by heating the sample in the temperature range of 250-360 o C under non-oxidative conditions was characterized using MALDI-TOF (matrix assisted laser desorption/ionization) mass spectrometry. The structures of the degradation products were determined and the relative compositions were estimated. The MALDI-TOF mass spectra of the thermally degraded PTT sample showed three main series of oligomer products with different end groups, which were carboxyl/carboxyl, carboxyl/allyl, and allyl/allyl. In contrast to the thermal degradation of polyethylene terephthalate (PET), the oligomers containing terephthalic anhydrides were not detected, whereas the formation of oligomers containing the unsaturated allyl ester group was confirmed by mass assignment. From these results, it was concluded that the thermal degradation of PTT proceeds exclusively through the β-CH hydrogen transfer mechanism, which is in accordance with the proposed reaction mechanism for the thermal degradation of polybutylene terephthalate (PBT).

Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

“…Previous studies show PBAT degradation at 180–200 °C, probably due to hydrolysis or β-C–H hydrogen transfer. This is similar to polybutylene terephthalate and polypropylene terephthalate degradation, generating COOH and chain-terminating groups (e.g., allyl, butenyl ester end groups). − These chain-terminating end groups are reported to cause a decrease in molecular weight . Therefore, medium molecular weight PPAT polyesters from this first polymerization stage were produced for subsequent postpolymerization before molecular weight decrease from degradation occurred.…”

“…Previous studies on poly­(ethylene terephthalate) synthesis show that higher temperature, higher vacuum, and thinner films facilitated the diffusivity of byproducts in polymer melts . However, overly high temperatures (>240 °C) and long reaction times caused degradation of polypropylene terephthalate and polybutylene terephthalate and increased carboxyl groups. ,, Therefore, the effects of reaction temperatures on the polycondensation of PPAT were explored.…”

Mechanical and Thermo-Physical Properties of Short Glass Fiber Reinforced Polybutylene Terephthalate upon Aging in Lubricant/Refrigerant Mixture

“…Degradation mechanisms of aromatic polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) have been extensively studied over the past few decades [4][5][6][7][8][9][10] . Notwithstanding, just recently these polymers began to be aimed for engineering and structural applications.…”