Curing kinetics of nanostructured epoxy blends toughened with epoxidized carboxyl-terminated liquid rubber

Zhao, Kai; Wang, Juan; Song, Xing Shun; Liang, Changsheng; Xu, Shiai

doi:10.1016/j.tca.2015.02.007

Cited by 26 publications

(13 citation statements)

References 49 publications

(71 reference statements)

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“…This could be because of the reduction of epoxy concentration in the composite system and the decreased overall curing degree. 35 The curing extent can be described by conversion ratio which is calculated by the eqn (2) below:…”

Section: Resultsmentioning

confidence: 99%

Rigid thermosetting epoxy/multi-walled carbon nanotube foams with enhanced conductivity originated from a flow-induced concentration effect

Liu

Bao

et al. 2016

RSC Adv.

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Herein, multi-walled carbon nanotube (MWCNT) reinforced rigid epoxy foams were innovatively prepared using expandable microspheres. A two-step technique, including prepolymerization and consecutive foaming, was employed to avoid the thermal degradation of epoxy due to the uncontrolled violent curing reaction. The effects of foaming on the MWCNT inter-connectivity, electrical percolation threshold, and through-plane electrical conductivity were investigated. Moderately foamed epoxy/ MWCNT composites were confirmed to have better conductivity than their solid counterparts at the same MWCNT content. An effect we called flow-induced concentration increases the inter-connectivity by separating MWCNTs from a flowing matrix caused by thermally triggered expansion of microspheres, and changes the MWCNT distribution. For the foamed composites with 2 wt% microspheres, the electrical percolation threshold is approximately 0.3 wt% and the conductivity is obviously higher than that of the solid counterpart. Relationships between microstructures and conductivities were also discussed. The mechanical property and cellular structures of conductive foams obtained under different foaming temperatures, prepolymerization time, microsphere and MWCNT contents were respectively evaluated. All the results reveal that lightweight conductive epoxy foams with lower filler content and enhanced conductivity can be fabricated for applications in electronics, automobiles, and aerospace.

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Section: Resultsmentioning

confidence: 99%

Rigid thermosetting epoxy/multi-walled carbon nanotube foams with enhanced conductivity originated from a flow-induced concentration effect

Liu

Bao

et al. 2016

RSC Adv.

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“…The dissolved CTPB particles act as a plasticizer with an increase of free volume at relatively high content; thus, there existed a plasticizing effect which leads to a fall in EP resin stiffness. 6 The maximum value of the flexural strain at break was achieved at an optimum concentration of 20 phr of CTPB and then began to decrease with a further increase in CTPB content.…”

Section: Flexural Strengthmentioning

confidence: 93%

“…This means that the molecular chain can adjust its conformation to relieve the stress concentration and transfer stress, and an amount of elastic energy can be stored in the rubber particles, thus reducing the sensitivity of the matrix to defects and leading to an increase in toughness. 5,6 The elongation at break exhibited a rapid increase up to 20 phr of CTPB because CTPB acted as an initiator for yielding in the EP matrix. 18 Furthermore, the cross-link density of the blends decreased and predominated along with more cavitations and segregation of the particles, resulting in a corresponding fall in elongation at break.…”

Section: Tensile Propertiesmentioning

confidence: 99%

“…4,5 Modification by reactive liquid rubbers is one of the most common and widely used approaches to alleviate these deficiencies without significant loss in other properties. 6,7 Among the liquid rubbers, the modifications by carboxyl-terminated butadiene acrylonitrile copolymer (CTBN), 5,8 amine-terminated butadiene acrylonitrile (ATBN), 4,9 hydroxyl-terminated butadiene acrylonitrile copolymer (HTBN), 10,11 etc., have been investigated by various researchers. Normally, liquid rubber and EP resins are mixed to prepare a homogeneous solution, and the elastomeric phase when cured forms small discrete particles, typically in the micrometer range, which are dispersed in and bonded to the EP matrix.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Carboxyl-Terminated Polybutadiene Liquid Rubber Modified Epoxy Resin with Enhanced Toughness and Excellent Electrical Properties

Dong

Zhou

Sui

et al. 2016

Journal of Elec Materi

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The modification of epoxy (EP) resin with carboxyl-terminated polybutadiene (CTPB) liquid rubber was carried out in this work. The chemical reaction between the oxirane ring of EP and the carboxyl group of CTPB and kinetic parameters were investigated by Fourier transform infrared and differential scanning calorimetry. The resulting pre-polymers were cured with methyl hexahydrophthalic anhydride. Scanning electron microscopic observations indicate that the micro-sized CTPB particles dispersed uniformly in the EP matrix formed a two-phase morphology, mainly contributing to the improved toughness of the modified network. The best overall mechanical performance was achieved with 20 phr CTPB; above it, a fall in the strength and modulus was observed. The storage modulus and loss declined with the CTPB concentration due to its lower modulus and plasticizing effect from dynamic mechanical analysis measurements. Moreover, due to the weak polarity and excellent electrical insulation of CTPB, the CTPB-modified EP presented higher electrical resistivities and breakdown strength, and low dielectric permittivity and loss compared with neat EP.

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“…Since 1970s, scientists have tried to toughen epoxy resin by incorporation of rubber in epoxy matrix. Addition of reactive oligomers such as carboxyl‐terminated butadiene‐acrylonitril (CTBN) rubbers and preformed core‐shell particles were reported. Thermoplastics such as polyphenyl oxide and interpenetrating polymer networks were also tried to improve toughness of epoxy matrix .…”

Section: Introductionmentioning

confidence: 99%

A study of mechanical properties of biobased epoxy network: Effect of addition of epoxidized soybean oil and poly(furfuryl alcohol)

Roudsari

Misra

Mohanty

2016

J of Applied Polymer Sci

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A novel biobased thermoset interpenetrating network was introduced in this study. Epoxidized soybean oil (ESO) and poly(furfuryl alcohol) (PFA) were added to a commercial biobased epoxy resin. It was hypothesized that addition of ESO and PFA can decrease brittleness of bioepoxy resin and also increase biobased content. Mechanical properties of samples were evaluated using tensile and impact test. It was found that the addition of ESO and PFA increased notched Izod impact energy by 76.6%. This significant increase was related to incorporation of long flexible chains of ESO into the matrix. Hybridization of ESO and PFA in bioepoxy reduced tensile strength (around 70%), tensile modulus (around 90%), and glass transition temperature in comparison to neat bioepoxy. Tensile strength and modulus of hybridized system can be further improved by addition of natural fibers and the resultant composite may be considered as a good candidate for applications in which damping properties are important. Crosslink density was calculated using dynamic mechanical analysis and a decrease in crosslink density was observed in hybridized system. PFA domains were observed in the matrix using atomic force microscopy in peak force quantitative nano‐mechanical mode and it revealed inhomogeneity in the crosslinked structure. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44352.

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Curing kinetics of nanostructured epoxy blends toughened with epoxidized carboxyl-terminated liquid rubber

Cited by 26 publications

References 49 publications

Rigid thermosetting epoxy/multi-walled carbon nanotube foams with enhanced conductivity originated from a flow-induced concentration effect

Rigid thermosetting epoxy/multi-walled carbon nanotube foams with enhanced conductivity originated from a flow-induced concentration effect

A Carboxyl-Terminated Polybutadiene Liquid Rubber Modified Epoxy Resin with Enhanced Toughness and Excellent Electrical Properties

A study of mechanical properties of biobased epoxy network: Effect of addition of epoxidized soybean oil and poly(furfuryl alcohol)

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