Influence of polymerization conditions on melt crystallization of partially aliphatic polyimides

Preparation of polyimides derived from biphenyltetracarboxylic dianhydrides and aromatic diamines bearing alkylene spacers

“…With a longer alkylene chain the tensile strengths at break and initial moduli decreased due to the flexibility of the alkylene chain. It is interesting to note the "odd-even" behavior of the tensile properties of polymer VIII films similar to the reported behavior of the melting temperatures for these polymers 18 and for analogous aliphatic PIs 26,27 and as reported in the behavior of the tilt bias angle for aliphatic PIs. 28 Thus, tensile strengths at break and initial moduli of polymers with an even number of methylene spacers have larger values than those of polymers with an odd number of methylene spacers.…”

Enthalpies and entropies of fusion of ten alkane-α, ω-diamines H2 N– (CH 2)n– NH2 where 3⩽n⩽12

“…Alkane-α, ω-diamines are an industrially important class of monomers employed in the synthesis and preparation of a number of polymers. (1,2) Their solvation (3)(4)(5) and protonation (6)(7)(8) in aqueous solution have also been the subject of calorimetric studies since they are thought to act as biochemical model compounds.…”

Semi-Alicyclic Polyimides: Insights into Optical Properties and Morphology Patterning Approaches for Advanced Technologies

“…In recent years, some types of PIs were proven to be biocompatible [4], and they have been used in biomedical fields as flexible and implantable intracortical electrode arrays [5] and as microstructured substrates for contact guidance of cell growth [6], on condition of being patterned at micro or nanoscale. However, the strong intermolecular forces between the aromatic PI chains make them difficult to process because they decompose prior to melting and are insoluble in organic solvents [7][8][9]. One the other hand, the formation of intra-and intermolecular charge transfer complex (CTC) between the electron-donating diamine and the electron-accepting dianhydride moieties explains the coloration ranging from pale yellow to deep brown, causing strong absorption in the visible region [10,11], and enhance the dielectric constant.…”