Molecular dynamics in hyperbranched polyimides cross-linked with ethylene glycol diglycidyl ether

Maroulas, Panagiotis; Kripotou, S.; Sysel, Petr; Hobzová, Radka; Kotek, Jiřı́; Pissis, P.

doi:10.1016/j.jnoncrysol.2006.02.171

Cited by 8 publications

(3 citation statements)

References 14 publications

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“…In contrast, there are rather fewer studies of the molecular dynamics of cross-linking systems in which HBPs are incorporated, and of how the relaxation behaviour changes as the cross-linking reaction proceeds. Maroulas et al [ 73 ] investigated the molecular dynamics in hyperbranched polyimides cross-linked with ethylene glycol diglycidyl ether and found that the γ-relaxation becomes slower but increases in magnitude as the cross-linking proceeds. This apparently anomalous behaviour was attributed to the sum of two opposing effects: an increase in free volume accompanied by increased constraint as a result of the crosslinking.…”

Section: Introductionmentioning

confidence: 99%

Study of Hyperbranched Poly(ethyleneimine) Polymers of Different Molecular Weight and Their Interaction with Epoxy Resin

2018

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Two different commercial hyperbranched poly(ethyleneimine)s (HBPEI), with molecular weights (MW) of 800 and 25,000 g/mol, and denoted as PEI800 and PEI25000, respectively, as well as the mixtures with a Diglycidyl Ether of Bisphenol-A (DGEBA) epoxy resin, have been studied using thermal analysis techniques (DSC, TGA), dielectric relaxation spectroscopy (DRS), and dynamic mechanical analysis (DMA). Only a single glass transition is observed in these mixtures by DSC. DRS of the HBPEIs shows three dipolar relaxations: γ, β, and α. The average activation energy for the γ-relaxation is similar for all HBPEIs and is associated with the motion of the terminal groups. The β-relaxation has the same average activation energy for both PEI800 and PEI25000; this relaxation is attributed to the mobility of the branches. The α-relaxation peak for all the HBPEIs is an asymmetric peak with a shoulder on the high temperature side. This shoulder suggests the existence of ionic charge trapped in the PEI. For the mixtures, the γ- and β-relaxations follow the behaviour of the epoxy resin alone, indicating that the epoxy resin dominates the molecular mobility. The α-relaxation by DRS is observed only as a shoulder, as a consequence of an overlap with conductivity effects, whereas by DMA, it is a clear peak.

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Section: Introductionmentioning

confidence: 99%

Study of Hyperbranched Poly(ethyleneimine) Polymers of Different Molecular Weight and Their Interaction with Epoxy Resin

2018

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“…Boiteux and co-workers [ 64 , 65 , 66 ] investigated the molecular dynamics in polyurethane networks cross-linked with hyperbranched polyesters and observed that the secondary β- and γ-relaxations were unaffected by the degree of cross-linking of the network, which was modified by varying the polyurethane chain length. On the other hand, Maroulas et al [ 67 ] investigated the molecular dynamics in hyperbranched polyimides cross-linked with ethylene glycol diglycidyl ether and found that the γ-relaxation, which was faster in the hyperbranched system than in its linear analogue, becomes slower but increases in magnitude as the cross-linking proceeds. This apparently anomalous behaviour was attributed to the sum of two opposing effects: an increase in free volume accompanied by increased constraint as a result of the crosslinking.…”

Section: Introductionmentioning

confidence: 99%

Molecular Mobility in Hyperbranched Polymers and Their Interaction with an Epoxy Matrix

2016

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The molecular mobility related to the glass transition and secondary relaxations in a hyperbranched polyethyleneimine, HBPEI, and its relaxation behaviour when incorporated into an epoxy resin matrix are investigated by dielectric relaxation spectroscopy (DRS) and dynamic mechanical analysis (DMA). Three systems are analysed: HBPEI, epoxy and an epoxy/HBPEI mixture, denoted ELP. The DRS behaviour is monitored in the ELP system in three stages: prior to curing, during curing, and in the fully cured system. In the stage prior to curing, DRS measurements show three dipolar relaxations: γ, β and α, for all systems (HBPEI, epoxy and ELP). The α-relaxation for the ELP system deviates significantly from that for HBPEI, but superposes on that for the epoxy resin. The fully cured thermoset displays both β- and α-relaxations. In DMA measurements, both α- and β-relaxations are observed in all systems and in both the uncured and fully cured systems, similar to the behaviour identified by DRS.

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“…Zhou et al fabricated PI films using BPDA and 1,4-phenylenediamine (PDA) as structural units and 1,3,5-tris(4-aminophenoxy) benzene (TAPOB) as cross-linking agent (Figure a). The carefully designed branched-cross-linked structures containing branched chains break the mutual constraint between low permittivity and low thermal expansion in PI. , The cross-linked PI showed a reduction in the dielectric constant of about 8.8% (Figure b). Based on this, Han et al synthesized four PI molecules using PMDA and 6FDA as dianhydride monomers, ODA and TFMB as diamine monomers, and TAPOB as cross-linking agent (Figure c).…”

Section: Molecular-scale Regulationmentioning

confidence: 99%

Versatile Landscape of Low-k Polyimide: Theories, Synthesis, Synergistic Properties, and Industrial Integration

Dong,

Wan,

Zha

2024

Chem. Rev.

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The development of microelectronics and large-scale intelligence nowadays promotes the integration, miniaturization, and multifunctionality of electronic and devices but also leads to the increment of signal transmission delays, crosstalk, and energy consumption. The exploitation of materials with low permittivity (low-k) is crucial for realizing innovations in microelectronics. However, due to the high permittivity of conventional interlayer dielectric material (k ∼ 4.0), it is difficult to meet the demands of current microelectronic technology development (k < 3.0). Organic dielectric materials have attracted much attention because of their relatively low permittivity owing to their low material density and low single bond polarization. Polyimide (PI) exhibits better application potential based on its well permittivity tunability (k = 1.1−3.2), high thermal stability (>500 °C), and mechanical property (modulus of elasticity up to 3.0−4.0 GPa). In this review, based on the synergistic relationship of dielectric parameters of materials, the development of nearly 20 years on low-k PI is thoroughly summarized. Moreover, process strategies for modifying low-k PI at the molecular level, multiphase recombination, and interface engineering are discussed exhaustively. The industrial application, technological challenges, and future development of low-k PI are also analyzed, which will provide meaningful guidance for the design and practical application of multifunctional low-k materials.

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Molecular dynamics in hyperbranched polyimides cross-linked with ethylene glycol diglycidyl ether

Cited by 8 publications

References 14 publications

Study of Hyperbranched Poly(ethyleneimine) Polymers of Different Molecular Weight and Their Interaction with Epoxy Resin

Study of Hyperbranched Poly(ethyleneimine) Polymers of Different Molecular Weight and Their Interaction with Epoxy Resin

Molecular Mobility in Hyperbranched Polymers and Their Interaction with an Epoxy Matrix

Versatile Landscape of Low-k Polyimide: Theories, Synthesis, Synergistic Properties, and Industrial Integration

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