Effect of copolymerization on crystallization kinetics of semicrystalline polyimides

Abstract

Isothermal melt crystallization kinetics and nonisothermal cold crystallization kinetics of co-PI based on 3, 3 0 , 4, 4 0 -biphenyltetracarboxylic dianhydride (s-BPDA)/1, 3-bis-(4-aminophenoxy) benzene (TPER)/4, 4 0 -oxydianiline(4, 4 0 -ODA), and TPER PI (s-BPDA/TPER) have been investigated. Avrami equation was used to analyze isothermal melt crystallization progress of TPER PI and co-PI, primary crystallization processes was found to be changed as the introduction of 4, 4 0 -ODA. Total activation energy DE for TPER PI and co-PI were found to be À404 and À86 kJ mol À1 by Arrhenius equation. Jeziorny's analysis, Ozawa's analysis, and Mo's approach were used to investigate nonisothermal cold crystallization progress of TPER PI and co-PI. Activation energy DE non for TPER PI and co-PI were found to be 247 and 193 kJ mol À1 by Kissinger equation. The result indicated that co-PI exhibited lower crystallization rate than TPER PI when isothermally crystallized from melt, but higher crystallization rate under cold nonisothermal crystallization progress.

High‐performance crystallized composite carbon nanoparticles/polyimide fibers

“…The development of semicrystalline PIs has attracted considerable attention from various researchers. [16][17][18] The most famous semicrystalline PIs include LaRC-CPI developed by NASA, 19,20 New-TPI developed by Mitsui Toatsu Chemicals, 21 and several other partially crystalline PIs developed by Virginia Polytechnic Institute. 22 Although these PIs exhibit crystallinity, most of them can crystallize only in the presence of a solvent and are not capable of recrystallizing after their transition from the melt state.…”

Morphological Transformation in Polymer Composite Materials Filled with Carbon Nanoparticles: Part 2—Thermal and Mechanical Properties

“…Considerably less attention is paid to the study of long-term mechanical characteristics (creep)—apparently, this is due to the long duration of such testing [ 7 ]. At the same time, low creep resistance can severely limit the use of any structural materials, including the polymers.…”

Melt-Processable Semicrystalline Polyimides Based on 1,4-Bis(3,4-dicarboxyphenoxy)benzene Dianhydride (HQDPA): Synthesis, Crystallization, and Melting Behavior

“…However, the introduction of crystallinity could serve as an effective approach to improve the thermal stability, solvent resistance, and mechanical properties of polymers. Hence, development of semicrystalline polyimides has attracted considerable attention for these years [6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22]. The most well-known semicrystalline polyimides include LaRC-CPI developed by NASA [23,24,25,26,27,28], New-TPI developed by Mitsui Toatsu Chemicals [29,30,31,32], R-BAPB type polyimides developed by the Russian Academy of Sciences [33,34,35,36], and some other semicrystalline polyimides developed by the University of Akron [37,38,39,40] and Virginia Polytechnic Institute [41,42,43,44,45].…”

“…Firstly, backbone structures always contain ether, carbonyl or biphenyl connecting groups [13,14,23,24,31,32,33,34,35]. Secondly, diamines containing flexible ether groups such as 3,4′-oxydianiline (3,4′-ODA), 1,3-bis(4-aminophenoxy)benzene (TPER), and 4,4′-bis(4-aminophenoxy) biphenyl (BAPB) and their isomers are preferred [8,9,10,11,12,14,29,30,31,32,33,34,35,41,42,43,44,45]. In particular, it was found that the polyimides based on TPER or 3,4′-ODA exhibited excellent melt recrystallization ability and high crystallization rates [14,41,42].…”