Synthesis and Characterization of Novel Processable and Flexible Polyimides Containing 3,6-Di(4-carboxyphenyl)pyromellitic Dianhydride

Table 3

Thermal stability of the polyimides (PI-1–PI-6).

Polymer code	(°C)	Thermal stability
		(°C)^a	(°C)^b	(°C)^c	Char yield (%)^d
PI-1	250	455	480	500	58
PI-2	325	470	498	498	60
PI-3	270	498	525	495	65
PI-4	280	460	485	525	59
PI-5	335	490	515	520	63
PI-6	310	498	520	496	64

%, %: temperatures at 5, 10% weight loss, respectively.
^cTemperature of maximum decomposition rate.
^dResidual weight when heated to 600°C in nitrogen.