Microstructural features, diffusion and molecular relaxations in polyimide/silica hybrids

Musto, Pellegrino; Abbate, Mario; Lavorgna, Marino; Ragosta, G.; Scarinzi, Gennaro

doi:10.1016/j.polymer.2006.05.074

Cited by 53 publications

(45 citation statements)

References 32 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They reported an increase in storage modulus all over the 100-400 C temperature range and a decrease in intensity of the a relaxation peak on tan d, while Ta slightly increases with silica concentration. As has been previously reported by other authors in a complete study of similar systems [74] and in accordance with perfluorosulfonic ionomer-based composite behavior, these evolutions are related to the interactions between the silica particles and PBI. Fluorinated polyoxadiazole exhibits a slightly different behavior with hydrophilic functionalized silica [75].…”

Section: Nonfluorinated Polymer-based Hybrid and Composite Membranessupporting

confidence: 89%

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

Chailan

Khadhraoui

Knauth

2012

Solid State Proton Conductors

View full text Add to dashboard Cite

Section: Nonfluorinated Polymer-based Hybrid and Composite Membranessupporting

confidence: 89%

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

Chailan

Khadhraoui

Knauth

2012

Solid State Proton Conductors

View full text Add to dashboard Cite

“…Figures 6 and 7 report the DMA results obtained by Musto et al [42] on two types of PI/silica hybrids having, respectively, a particulate micron sized structure and nano-structured co-continuous morphology. The alkoxysilane solutions used for the production of these hybrids were pure TEOS for the phase separated system and a TEOS/GOTMS mixture for the interconnected hybrid.…”

Section: Dynamic Mechanical Propertiesmentioning

confidence: 99%

“…The highest temperature transition is an α-relaxation process (Figure 7b) and corresponds to the glass transition temperature (T g ). The β transition is generally associated with local bond rotations along the polyimide backbone, although its exact description is still uncertain [42]. The γ transition is observed only in the presence of absorbed moisture.…”

Section: Dynamic Mechanical Propertiesmentioning

confidence: 99%

Polyimide/silica hybrids via the sol-gel route: High performance materials for the new technological challenges

Ragosta¹,

Musto²

2009

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. The present review article describes in detail the state-of-the-art of organic-inorganic hybrid materials based on polyimide/silica components. The article is divided in three parts. In the first the basic processing route for the preparation of these systems is described, i.e. the sol-gel technique, along with the strategies developed to control the final morphology. In the second part the curing characteristics, the dynamic-mechanical and the mechanical and fracture properties of hybrids with different morphologies are reviewed. Finally, the more technologically relevant applications devised for these high performance materials are discussed. : nanocomposites, hybrid materials, polyimide, silica, sol-gel eXPRESS Polymer Letters Vol.3, No.7 (2009) [413][414][415][416][417][418][419][420][421][422][423][424][425][426][427][428] Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2009.51 or as functional materials [14] such as catalyst supports [15] and microelectronic devices [16]. The sol-gel route represents the preferred way for the synthesis of polyimide based hybrids. The classical sol-gel process consists in a two step hydrolysis-condensation reaction, starting with a metal alkoxides M(OR) 4 , typically tetraethoxisilane Si(OCH 2 CH 3 ) 4 or titanium isopropoxide Ti[OCH(CH 3 ) 2 ] 4 , to produce hydroxyl groups followed by the polycondensation of the hydroxyl groups and residual alkoxy groups to form a three-dimensional network [5,[17][18][19][20][21]. Polyimides are particularly suited for this type of process because they can be obtained from polyamic acid precursors, which are soluble in hygroscopic solvents and can, therefore, tolerate the addition of water necessary to bring about the hydrolysis of the metal alkoxide. Moreover, the outstanding thermal stability of polyimides allows the hybrids to be post-cured at very high temperatures (300-350°C) making it possible the development of a very dense inorganic network without inducing appreciable degradation of the organic phase. Polyimide/silica hybrids made by the sol-gel technique are the subject of this review, in which the approaches used for a close control of their final morphology, the effects of the silica phase on the curing process of polyimide precursors, the dynamic-mechanical and the mechanical and fracture properties that these materials can display, and their possible applications will be presented and discussed. Keywords Processing and morphologyA typical procedure for the preparation of PI/silica hybrids via the sol-gel route, involves the following steps: i) The polyamic acid (PAA) (PI precursor) is formed by a polyaddition reaction of a dianhydride [e.g., pyromellitic anhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), or 2,2-bis(3,4-dicarboxy-phenyl)-hexafluoropropane dianhydride (6FDA)] with a diamine [e.g., 4,4′-oxydianiline (ODA), or p-phenylen diamine (PPA)] in a common solvent [e.g., dimethylacetamide (DMAc), or N-methyl pyrolidone (NMP)]. The reaction and chemical str...

show abstract

“…Typically, three relaxation processes are observed with increasing temperature designated as c, b, and a, respectively, with a corresponding to the glass-rubber relaxation. There are some reports, which refer to the characterization and analysis of the electrical and dynamical properties of polyimide hybrid films [36][37][38][39][40][41][42][43][44]. The properties of these materials are dependent on the interphase between filler and the polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films

Hamciuc¹,

Hamciuc²,

Okrasa

et al. 2012

J Mater Sci

View full text Add to dashboard Cite

Zeolite L, with the ratio Si/Al = 4, was prepared by hydrothermal method and used to obtain composite films based on a polyimide matrix having pendant carboxylic groups. The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films was studied. The films were prepared by casting a suspension resulting from direct mixing of a poly(amic acid) (PAA) solution and zeolite L particles onto glass plates, followed by thermal imidization under controlled temperature conditions. The PAA was synthesized by solution polycondensation of a mixture of two diamines, 3,5-diaminobenzoic acid and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (molar ratio 1:3), with 4,4 0 -oxydiphthalic anhydride, using N-methyl-2-pyrrolidone as solvent. To improve the compatibility between organic and inorganic phases, the surface of zeolite particles was modified by treating with 3-aminopropyltriethoxysilane. The surface morphology of the composite films investigated by scanning electron microscopy showed good compatibility between filler and polymer matrix. The films were flexible, tough, and exhibited high-thermal stability, having the initial decomposition temperature above 450°C. Dynamic mechanical analysis and dielectric spectroscopy revealed sub-glass transitions, c and b, and an a relaxation corresponding to the segmental motions above the glass transition temperature. The values of the dielectric constant at 10 kHz and 200°C were in the range of 3.3-4.2.

show abstract

Microstructural features, diffusion and molecular relaxations in polyimide/silica hybrids

Cited by 53 publications

References 32 publications

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

Polyimide/silica hybrids via the sol-gel route: High performance materials for the new technological challenges

The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films

Contact Info

Product

Resources

About