Synthesis and characterization of chemically cross-linked polyimide–siloxane hybrid films

Ahmad, Zahoor; Al‐Sagheer, Fakhreia; Arbash, A. Al; Ali, Asma

doi:10.1016/j.jnoncrysol.2009.01.019

Cited by 33 publications

(32 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Os espectros FTIR de polisiloxanos também costumam apresentar máximos em 1144, 1174 e 1198 cm -1 , atribuídos a estruturas contendo anéis cíclicos com 4, 5 e 6 membros, respectivamente. [24][25][26] Outra banda de absorção importante está relacionada a vibrações da ligação Si-OH em ~950 cm -1 . [27][28][29] No caso das resinas epóxi novolaca, entre os vários picos de absorção que podem ser observados em seus espectros FTIR, o de maior importância é o pico em ~912 cm -1 referente ao anel epóxi.…”

Section: Resultados E Discussão Análises Dos Espectros De Radiação Deunclassified

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

et al. 2016

View full text Add to dashboard Cite

publicado na web em 12/10/2016 HIGH LAYER COATING OBTAINED IN THE REACTION OF MODIFIED NOVOLAC EPOXYS RESINS WITH ORGANOSILOXANES THROUGH ACID CATALYSIS. Epoxy resins are an important class of thermostable polymers, widely used in structural applications or as adhesives. However, the low fracture resistance is their main weakness in many applications. Due to this fact, this study aims to modify a polymer matrix based on a novolac epoxy resin with an organo siloxane (AMS). The final properties of cured epoxys resins are affected by the curing process and the coatings modified in this study with AMS and cured with acid catalyst presented greater resistance to thermal decomposition compared to that cured with Aradur, demonstrating a higher content of crosslinking in the siloxane polyether and the novolak epoxy resin chains. This epoxy matrix modified was used to prepare coatings whose films applied to 1020 steel surfaces presented a resistance of 10 10 Ohm-cm -2 . This resistance value is one order of magnitude greater than that of epoxy resins films modified by siloxanes in published studies, which demonstrates a potential economy in terms of maintenance costs of metal structures and machines used in power plants (UTE). To obtain the developed inks in pilot plant scale, it was used an aromatic polyamine as curing agent, characterizing the product obtained as an epoxy bi-component paint for commercial use.Keywords: Corrosion, novolac epoxy resin, interpenetrating polymer network-IPN, polyether siloxane, coatings. INTRODUÇÃOAs resinas epóxi são uma importante classe de polímeros termoestáveis, amplamente utilizadas em aplicações estruturais ou como adesivos, devido a suas características de alta tensão e módulo, fácil processamento, boa resistência química e térmica e alta aderência a muitos substratos. Os sistemas epóxi apresentam pequena contração após a cura (em média, 2%), o que indica a necessidade de um baixo grau de rearranjo molecular para formar o sistema curado. Quanto à estabilidade química, o epóxi é um dos termorrígidos mais inertes, além de possuir boa estabilidade dimensional. Entretanto, revestimentos à base de resinas epóxi apresentam hidrofobicidade, baixas resistência ao impacto e à exposição a ambientes abertos, estabilidade térmica relativamente baixa e, em muitas aplicações, sua principal desvantagem é sua baixa resistência à fratura. Por essas razões, as resinas epóxi são frequentemente modificadas buscando aprimorar suas características.Conforme estudo de Gu et al., 1 têm sido introduzidas nanopartículas inorgânicas (SiO 2 , ZrO 2 , ZnO) em matrizes epóxi que atuam preenchendo os defeitos, como microfissuras e vazios, do revestimento epóxi, com o intuito de aprimorar suas propriedades anticorrosivas modificando seu efeito como barreira física. A otimização de propriedades, principalmente mecânicas, das resinas epóxi e dos polímeros termofixos também pode ser alcançada pela modificação da estrutura do polímero, aumentando-se a cadeia em pontos de entrecruzamento. 2 De forma geral, a introdução...

show abstract

Section: Resultados E Discussão Análises Dos Espectros De Radiação Deunclassified

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

et al. 2016

View full text Add to dashboard Cite

show abstract

“…20 The bands at 1200-1000 cm −1 are ascribed to the asymmetric vibrations of the siloxane groups (Si-O-Si), which were formed during the condensation reaction of APTES. 21,22 A comparison of Figs. 1a and 1b reveals that the carboxyl carbonyl band at 1718 cm −1 is decreasing whereas the intensities of the amide I (1625 cm −1 ) and the amide II (1579 cm −1 ) bands are increasing.…”

Section: Ft-ir Spectroscopymentioning

confidence: 99%

Ladder-Like Aromatic Imide-Functionalized Poly(silsesquioxane): Preparation and Characterization via the Sol-Gel Route

Schramm

Rinderer

Tessadri

2015

Adv. Polym. Technol.

View full text Add to dashboard Cite

ABSTRACT:A ladder-like polysilsesquioxane (PSSQ) has been synthesized by reacting pyromellitic acid anhydride (PMDA) with (3-aminopropyl)triethoxysilane (APTES), yielding the corresponding poly(amic acid) (PAA). The as-prepared PAA was converted to an imide-functionalized PSSQ by thermal treatment at 220°C. The material was characterized by means of Fourier transform infrared spectroscopy, 13 C and 29 Si solid-state magic angle nuclear magnetic resonance spectroscopy, X-ray powder diffraction, thermogravimetric analysis, and differential thermogravimetric analysis. The findings give evidence that a ladder-like PSSQ is formed when PMDA reacts with APTES in a molar ratio of 1:1. Kinetic studies of the adsorption of methylene blue (MB) reveal that PMDA/APTES (molar ratio = 1:1) is capable of adsorbing MB whereas PMDA/APTES (molar ratio = 1:2) shows almost no MB adsorption capacity. C

show abstract

“…The mechanical and thermal properties of polymeric matrices in such systems show improvement on addition of different inorganic networks. Various polymers such as polyaramids [3,4], polyimides [5,6], epoxies [7,8], poly(dimethylsiloxanes) [9], among many others have been used to prepare advanced composite materials. Different processes have been used to prepare such materials among which the sol-gel process [10,11] is considered to provide many advantages including mild processing conditions and variation in the relative composition of the inorganic and organic phases.…”

Section: Introductionmentioning

confidence: 99%

“…The effect of both the coupling agent and the sol-gel process parameters on the organo-siloxane domain morphology was evaluated. Mascia et al [6] prepared epoxy-silica hybrids using tetraethoxysilane (TEOS) in tetrahydrofuran (THF) solution. The compatibilization was induced through functionalization by using a small amount of APTES.…”

Section: Introductionmentioning

confidence: 99%

“…The filler-matrix interface also plays an important role; if the T g of the interface is less than that of the matrix, the T g of the resulting composite may decrease, but if the T g of the interface is higher than that of the matrix, the T g of composite will increase by increasing filler content [29]. The silanes used previously [6,[19][20][21][22][23]27] to compatiblize the organic inorganic phases (e.g., 3-aminopropyl-triethoxysilane, N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane, 3-glycidoxy propyl-trimethoxysilane) had the propyl chain as interface which is considered to be very flexible. We in the present paper have used instead aminophenyl-trimethoxysilane (APTMOS) where the phenyl group acting as inter-phase is more rigid than the propyl chain used previously.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preparation and characterization of epoxy–silica networks chemically bonded through aminophenyl-trimethoxysilane

Ahmad

Al‐Sagheer

2014

J Sol-Gel Sci Technol

Self Cite

View full text Add to dashboard Cite

Epoxy-silica hybrids with interfacial bonding using aminophenyl-trimethoxysilane (APTMOS) have been prepared by the sol-gel process. In a sequential polymerization procedure the amine groups present on the APTMOS were used to partially cure diglycidyl ether of bisphenol-A (DGEBA) whereas the methoxy groups created silica-network simultaneously, through the sol-gel process. Complete curing and cross-linking were carried out later using curing agent jeffamine D-400 at higher temperature. The nature of silica network structure chemically bonded with the epoxy chains was studied by Fourier transformed infrared spectroscopy and the morphology of the hybrid through scattering electron and atomic force microscopies. The visco-elastic properties of the resulting hybrids were measured through dynamical thermal mechanical analysis. The effect of inter-phase bonding of the resulting hybrids and their thermal mechanical properties are compared with the similar DGEBA epoxy matrix where un-bonded silica network was produced from tetraethoxysilane. The properties of the hybrids using APTMOS show considerable improvement in thermal mechanical properties and the coefficient of thermal expansion is reduced in contrast to the un-compatiblized system.

show abstract

Synthesis and characterization of chemically cross-linked polyimide–siloxane hybrid films

Cited by 33 publications

References 35 publications

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

Revestimentos de alta camada obtidos com a modificação de resinas epóxi novolaca pela reação com organo-siloxano e catálise ácida

Ladder-Like Aromatic Imide-Functionalized Poly(silsesquioxane): Preparation and Characterization via the Sol-Gel Route

Preparation and characterization of epoxy–silica networks chemically bonded through aminophenyl-trimethoxysilane

Contact Info

Product

Resources

About