Influence of structural modification on the properties of poly(amide–imide)s

et al. 2023

Polymers

In order to adjust the properties of polyamide 6 (PA6) and expand its application, a new strategy of introducing an aromatic imide structure into the PA6 chain through the random copolymerization method is reported. The diimide diacid monomer was first synthesized by the dehydration and cyclization of pyromellitic dianhydride and 6-aminocaproic acid before it reacted with 1,6-hexamethylene diamine to form poly(amide imide) (PAI) salt, and finally synthesized PA6/PAI random copolymers containing an aromatic imide structure by the random copolymerization of ε-caprolactam and PAI salt. The introduction of an aromatic imide structural unit into the PA6 chain could have a great influence on its properties. As the content of PAI increases, the crystallinity (Xc) and melting temperature (Tm) of the PA6/PAI random copolymer gradually decrease, but its glass transition temperature (Tg) increases obviously. When the PAI content is 20 wt%, the copolymer PA6/PAI-20 has the best comprehensive performance and not only has high thermal stabilities but also excellent mechanical properties (high strength, high modulus, and good toughness) and dielectric properties (low dielectric constant and dielectric loss). Moreover, these properties are significantly superior to those of PA6. Such high-performance PA6 random copolymers can provide great promise for the wider applications of PA6 materials.

Section: Structure Characterization Of Dida Monomermentioning

confidence: 96%

Synthesis and Properties of Polyamide 6 Random Copolymers Containing an Aromatic Imide Structure

Zhang

et al. 2023

Polymers

“…As shown in the Scheme 1, the diimide-diacid (DIDA) was synthesized by the condensation of ODPA with 11-aminoundecanoic acid through dehydration cyclization, then PAI was prepared from 1,4-diaminobenzene and DIDA monomers through Yamazaki-Higashi phosphorylation reaction. [44][45][46][47][48][49] The proton nuclear magnetic resonance ( 1 H-NMR) spectra of DIDA and PAI are shown in Figure S1. Synthesis of DIDA.…”

Section: Synthesis Of Poly(amide-imide)mentioning

confidence: 99%

Obvious improvement of dispersion of multiwall carbon nanotubes in polymer matrix through careful interface design

Chang

Polymers for Advanced Techs

Horiuchi

et al. 2022

Self Cite

Herein, a simple and effective approach has been proposed to enhance the interfacial strength between multiwall carbon nanotubes (MWCNTs) and polymer matrix for improving the dispersion of MWCNTs. In more detail, a soluble polyaniline derivate containing polar group (POMA) was selectively incorporated into the binary blend of poly(amide-imide) (PAI) and MWCNTs. The surface energy and atomic force microscope measurements suggested that POMA was located at the interface of PAI and MWCNTs. Fourier transform infrared measurement indicated that POMA simultaneously interacted with MWCNTs and PAI by hydrogen bonding and π-π interaction, providing stronger interfacial strength between conductive filler and polymer matrix.As a result, the dispersion of MWCNTs and the surface roughness of PAI composites were obviously improved, which is helpful for charge and load transfer in the PAI/MWCNTs/POMA ternary films. As a result, the conductivity increased by 250% from 13 S m À1 for PAI/MWCNTs binary composites to 48 S m À1 for PAI/MWCNTs/ POMA ternary composites, and the tensile strength increased from 52 MPa for PAI/MWCNTs binary composites to 66 MPa for PAI/MWCNTs/POMA ternary composites. These findings imply that polar aromatic polymers with suitable surface energy will be a desirable compatibilizer for optimizing the dispersion of carbon nanotubes in the polymer matrix.

“…PAI was prepared by Yamazaki-Higashi phosphorylation reaction, as reported previously, [46][47][48][49][50] and the synthetic route is shown in Figure 3.…”

Section: Synthesis Of Paimentioning

confidence: 99%

Conductivity enhancement of poly(amide-imide) composites based on the synergistic effect of poly(o-methoxyaniline) and functionalized multiwalled carbon nanotube

Fang

Polymers and Polymer Composites

et al. 2020

Self Cite

A series of novel ternary conductive composites have been prepared by incorporating functionalized multiwalled carbon nanotubes (FMWCNTs) into the binary composites of poly(amide-imide) (PAI) and poly( o-methoxyaniline) (POMA) to further improve the conductivity of PAI composites. With increasing the weight ratio of FMWCNTs, the conductivity of PAI/POMA/FMWCNTs ternary composites has been significantly enhanced from 10−3 S m−1 to 90 S m−1, much higher than that of the sum of PAI/POMA and PAI/FMWCNTs binary composites. The enhanced conductivity is mainly ascribed from a much more intensive conductive network formed in the PAI/POMA/FMWCNTs ternary composites. It is found that the N–H bending of amide group in the Fourier transform infrared spectrometry spectra is observed at 3298 cm−1 for PAI, 3296 cm−1 for PAI/POMA binary composites, and further blue shifted to 3292 cm−1 for PAI/POMA/FMWCNTs ternary composites. Moreover, the glass transition temperature has been increased from 82.5°C to 117.7°C. These results suggested that the hydrogen bonding interaction has been strengthened among PAI, POMA, and FMWCNTs, which is useful for dispersion of condcutive fillers into the polymer matrix.