Melt processible polyimides and their chemical structures

Synthesis and properties of aromatic polyamides containing the cyclohexane structure

“…were used without further purification. According to a well-developed procedure, 5,32,33 ether diamines with four or five benzene rings that include 1,1-bis [4-(4- …”

Ionic Liquid-Catalyzed Preparation of Aromatic Polyamides Containing Phthalazinone Moiety

“…Thermal properties and glass transitions temperature (T g ) of the polymers were evaluated with TGA and DSC, respectively (Figures 3 and 4), and the characteristic data are summarized in Table 2. The T g value of PA [1][2][3][4][5][6][7][8] were in the range of 310-345 • C. In addition more than half of the polymers weight remained at 600 • C (char yields). The excellent thermal stabilities may be due to the presence of very rigid aromatic heterocyclic backbone.…”

“…Therefore, various efforts have been focused on the preparation of soluble and/or thermoplastic polyimides, while still maintaining the excellent thermal and mechanical properties. Typical approaches have been employed to improve the processability of these polyimides including the incorporation of flexible links [7], bulky pendant or cardo groups [8], kinked or unsymmetrical structures [9], and spiroskeletons [10] into the polymer chain. These modifications lower the melting temperature and lead to soluble and amorphous polymers.…”

Synthesis and characterization of new fluorene-based poly(ether imide)s

“…3 The linkages not only create angular bonds in the polymer chain, but also permit the rotation of aromatic units. However, the loss of thermal stability and significant decrease in tensile strength on heating are almost always a consequence of the reduced chain stiffness.…”