Synthesis and Characterization of Novel Polyimides

Synthesis and properties of polyimides from 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl

“…The order of increasing water absorption was PI2x < PI1x < PI3x. The water absorption decreased with the increasing number of phenylene units in case of polyimides, which were prepared from dianhydrides b, c, d, e and f as reported previously, 15,16 and decreased with decreasing imide content per repeating unit. The values of water absorption were plotted as a function of the imide group content for all the polyimides, PI1x, PI2x and PI3x, defined as the formula weight (O¼C-N-C¼O) per that of the repeating unit.…”

“…Aromatic polyimides PI1x and PI2x were synthesized by the usual two-step procedure 16 involving the ringopening polyaddition of the diamine 1 or 2 to the tetracarboxylic dianhydride (a-i) and subsequent thermal cyclodehydration as shown in Figure 2. In the first step, ring-opening polyadditions were carried out in NMP at room temperature, leading to the formation of polyamic acids, PAA1x and PAA2x, having inherent viscosities of 0.58-0.91 and 0.52-0.97 dL g À1 , respectively, in NMP ( Table 1).…”

“…Thus, the imide contents (formula weight of the imide group per repeating unit) of polyimides from 1 and 2 are lower than that of the polyimides from 3 . The polyimides with lower imide contents have been reported to show lower water absorption 14–16 and dielectric constants ( ∊ ). 17,18 We examined the possibility of lowering the water absorption and dielectric constants of polyimides using 1 and 2 , while maintaining the thermal stability and solubility of polyimides from 3 .…”

Synthesis and Properties of Polyimides from Aromatic Dianhydrides Having Various Number of Phenylene Units and Bis{4-[4-(4-aminophenoxy)phenoxy]phenyl}Ether

“…The properties were compared with those of polyimides from DA-0 and DA-1, and discussed on the basis of the number (m) of phenylene units [9,10]. The T g values depended on the connecting group and the structure of the diamine moiety, and were not dependent on m. The rotational barrier of the connecting group in the diamine moiety played a determining role in the value of T g [11,12].…”

Investigation of thermal and tensile properties of poly(benzimidazole-imide) composites incorporating salicylic acid–functionalized multiwalled carbon nanotubes

“…High performance polymers are well known for including all these aspects in a significant way. 1 As well, their exceptional chemical resistance to all kinds of acids makes them suitable for a broad range of applications like insulation and industrial carriage equipment. 2 Among heterocyclic polymers widely studied for high performance applications, aromatic polyimides (PI)s have received considerable interest due to their exceptional chemical, thermal, and mechanical stability.…”