High‐resolution thermogravimetry of polyphenylene sulfide film under four atmospheres

Abstract

Thermal degradation of polyphenylene sulfide (PPS) film was investigated in air, nitrogen, helium, and argon with different physical and reactive characteristics from room temperature to 790°C by a high-resolution thermogravimetry (TG) at a variable heating rate in response to the changes in the sample's weight-loss rate. In nitrogen and argon, only a single-step degradation process of the PPS was observed, but in helium, a two-step degradation process of PPS was found. Notably, in air a four-step degradation process of the PPS, which was hardly ever revealed by a traditional TG, was found in this investigation. The initial thermal degradation temperature T d and temperature at the first maximum weight-loss rate T dm1 of the PPS increased in the following order: in helium Ͻ in nitrogen Ͻ in argon Ͻ in air. The first maximum weight-loss rate also increased with the variation of atmosphere in the order: nitrogen Ͻ air Ͻ argon Ͻ helium. The char yield at 700°C increased in the order: in air Ͻ in helium Ͻ in nitrogen Ͻ in argon. The activation energy of the major degradation process of PPS calculated based on the high-resolution TG data was very high, increasing in the order: in nitrogen Ͻ in argon Ͻ in helium Ͻ in air. The thermal decomposition parameters of the PPS determined by the high-resolution TG were systematically compared with those by traditional TG at a constant heating rate.

Influence of process parameters on mechanical performance and bonding area of AA2024/carbon-fiber-reinforced poly(phenylene sulfide) friction spot single lap joints

“…Nevertheless, even the highest temperature achieved (474°C) in condition 16 is below the onset of degradation temperature of CF-PPS. The average onset degradation temperature of 516°C was measured for the composite part by thermogravimetric analysis (results to be published in a separate manuscript), which is in agreement with the results reported in the literature for the PPS matrix (onset temperature above 500°C) [25,26]. Furthermore, considering that the heating and cooling rates during the process are very fast (97°C/s and 17°C/s, respectively), extensive thermal degradation of the PPS matrix is not expected in the selected range of parameters in this study.…”

Melt processable homo- and copolyimides with high thermo-oxidative stability as derived from mixed thioetherdiphthalic anhydride isomers

“…It is worthwhile to note that the T 5% of these copolyimides in air is higher than that in nitrogen which is just contrary to a majority of PIs. This phenomenon has been found in the other sulfur-containing polymers, which is ascribed to the different degradation mechanisms in various atmospheres [12,22].…”

Synthesis and characterization of thioether-containing polyimides with high refractive indices

“…It should be noted that some PIs have T 5% and T 10% values that are higher in air than in nitrogen, as seen in Table 2. This phenomenon may be due to the different thermal conductivities and densities of the released gases, and it has also been observed for other sulfur-containing polyimides [35,36]. Furthermore, sulfide bonds are readily oxidized readily in air to form sulfonyl groups, resulting in an increase in weight.…”