Resinography of high polymers

Rochow, Theodore George

doi:10.1021/ac50154a005

Cited by 32 publications

(4 citation statements)

References 21 publications

(11 reference statements)

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“…It can be postulated that the NPs serve as a nucleation site for trans‐nodulation (TN). TN in epoxy resins has been reported earlier by Racich and Koutsky , who suggested that their size is in the tens of nanometer in diameter and typified by higher cross‐linking density compared to bulk epoxy []. It seems that the TN zone of higher modulus results in the crack bowing.…”

Section: Resultsmentioning

confidence: 66%

“…Various experimental techniques have subsequently indicated morphological inhomogeneities that could explain these low tensile strengths []. Electron microscopy has indicated featureless resins in some cases and a nodular or micellar structure in others []. Both the low tensile strengths and nodular morphology of thermosets have been theoretically related to differences or nonhomogeneous cross‐linking density [], though many investigators view thermosets as homogeneous, one‐phase materials.…”

Section: Introductionmentioning

confidence: 99%

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Nanoinduced morphology and enhanced properties of epoxy containing tungsten disulfide nanoparticles

Shneider

Dodiuk

Tenne

et al. 2013

Polymer Engineering & Sci

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Closed-cage (fullerene-like) nanoparticles (NPs) of WS 2 are currently produced in large amounts and were investigated as additives to thermoplastics and thermosetting polymers. The nanoinduced morphology and the resulting enhanced fracture toughness of epoxy/WS 2 nanocomposites were studied. The morphology of the epoxy nanocomposites was induced by controlled WS 2 surface chemistry. The WS 2 NPs used were either untreated or chemically treated with acryloxy, which is compatible, and alkyl silane, which is incompatible, respectively, with the epoxy matrix. In the case where the acryloxy silane was used to treat the WS 2 particles, good dispersion and compatibility were obtained in the epoxy resin . Moreover, a distinct nodular morphology was induced on fracture as a result of nucleation by the compatible NPs. In the case where the alkyl silane treatment was used cavitation morphology was induced, following mechanical loading, which is the result of incompatibility with the epoxy resin. The fracture toughness results showed an increase of 70% for nanocomposites contains alkyl-treated WS 2 compared with the neat epoxy. Modeling of the nodular morphology enabled the determination of optimal concentration of the WS 2 in epoxy (0.3% by weight). Two main fracture mechanisms were observed, crack bowing around the nodular boundaries in the case of compatibility between the nanoparticle and the epoxy and particle-induced cavitation in the case of incompatibility, respectively. These results are of significant importance both for epoxy-based adhesives and fiber composites. FIG. 2. (a) SEM micrograph of fracture surface of epoxy/0.5 wt% acryloxy-treated WS 2 NPs. (b) Epoxy/ 0.5 wt% alkyl-treated WS 2 NPs.

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Section: Resultsmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Nanoinduced morphology and enhanced properties of epoxy containing tungsten disulfide nanoparticles

Shneider

Dodiuk

Tenne

et al. 2013

Polymer Engineering & Sci

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“…In addition, Racich et al investigated the nodulation in epoxy resins. They reported that nodules are characterized by higher crosslinking density and higher modulus compared with bulk epoxy . Thus, it can be assumed that a high content of the stiff BE molecules caused the formation of nodular zones.…”

Section: Resultsmentioning

confidence: 99%

Toughening of epoxy systems by brominated epoxy

Sheinbaum

Weizman

et al. 2018

Polymer Engineering & Sci

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Blends of brominated epoxy (BE) and conventional epoxy resins were studied following curing with aliphatic triethylenetetramine (TETA), etheric (polyether diamine-PEA4), and aromatic (3,3 0 -diamino diphenyl sulfone [DDS]) hardeners. The addition of BE resulted in an increase in T g in all tested blends. Blends with 50 wt% BE cured with TETA demonstrated an increase in flexural modulus and flexural strength, while preserving the elongation. Blends with 40 wt% BE cured with PEA4 and 50 wt% BE cured with DDS resulted in a significant enhanced tensile elongation. The shear strength of all cured systems decreased moderately with the addition of BE exhibiting a mixed mode failure. Analysis of the fracture morphology using electron microscopy supported the increase of toughness levels as a result of incorporating BE to conventional epoxy. A unique nodular and rough fracture morphology was obtained, which is related to a toughening mechanism caused by the addition of BE. It was concluded that blends of BE and conventional epoxy could be used as structural adhesives having high T g , enhanced mechanical properties and increased toughness. POLYM. ENG. SCI., 00:000-000, 2018.FIG. 6. SEM micrograph of fractured surface of DGEBA/BE blends: (a) DGEBA cured by PEA4, (b ) the magnified image of the small square in a, (c) 40 wt% BE blend PEA4 -cured system, (d) the magnified image of the small square in (c), (e) 60 wt% BE blend PEA4-cured system, (f) the magnified image of the small square in (e).

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“…There are also wide varieties of chemically modified physically treated, delicately coated and intimately coordinated fibers (55,56,57,118,390,391,433,515). When chese complexities are added to those of integration and fabrication, it becomes evident that an investigator must analyze his problem and plan his microscopical research with due regard to the number and relationship of molecular associations present, using a classification scheme such as that proposed by Rochow (387,388,389).…”

Section: Fibersmentioning

confidence: 99%