Abstract Here we report the effect of multi-walled carbon nanotubes (MWCNTs) and thermally reduced graphene (TRG) on the miscibility, morphology and final properties of nanostructured epoxy resin with an amphiphilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer. The addition of nanoparticles did not have any influence on the miscibility of PEO-PPO-PEO copolymer in the resin. However, MWCNTs and TRG reduced the degree of crystallinity of the PEO-rich microphases in the blends above 10 wt.% of copolymer while they did not change the phase morphology at the nanoscale, where PPO spherical domains of 20–30 nm were found in all the samples studied. A synergic effect between the self-assembled nanostructure and the nanoparticles on the toughness of the cured resin was observed. In addition, the nanoparticles minimized the negative effect of the copolymer on the elastic modulus and glass transition temperature in the resin.
In this article, the potential of amine-functionalized poly(styrene) (PS) microspheres as toughening agent for epoxy resin has been explored. PS microspheres were prepared by suspension polymerization, where the monomer concentration and stirring speed was varied to control the microsphere dimensions (52–183 µm). The obtained microspheres were chemically functionalized with an aim to improve its dispersion within the epoxy matrix. The amine groups generated on the microsphere surface offer a pot...
Abstract Long processing cycle makes vacuum assisted resin infusion molding (VARIM) only suitable for low and medium volumes of production, and shortening of curing time is critical to improving the processing efficiency of automotive composite parts. In this paper, unidirectional carbon fiber reinforced composite laminates were fabricated by VARIM. Three different processes (namely quick, quick-post and preheating) were employed, in which a kind of rapid curing epoxy resin is used. The preheati...
Novel nanostructured unsaturated polyester resin-based thermosets, modified with poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and two poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) block copolymers (BCP), were developed and analyzed. The effects of molecular weights, blocks ratio, and curing temperatures on the final morphological, optical, and mechanical properties were reported. The block influence on the BCP miscibility was studied through uncured and cured mixtures of un...
Last. Luigi Torre(University of Perugia)H-Index: 13
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Abstract In this work the thermal behavior of a carbon-fiber composite impregnated with nano sized boron carbide based nanocomposites was investigated. First of all, the good dispersion and distribution of the particles in the matrix confirmed the effectiveness of the mechanical mixing. The presence of the ceramic filler did not affect the viscosity and the workability of the blends or the mechanical properties of the composites. The thermal stability of the fiber-reinforced materials was invest...
Abstract This paper compares the filler percolation network of multi-walled carbon nanotubes (MWCNTs) grown by chemical vapor deposition and thermally reduced functionalized graphene sheets (FGSs) in an epoxy resin. The filler network was evaluated by the plate–plate rheological response of un-cured dispersions and the electrical properties of cured materials. We found that FGS did not raise the viscosity of the system as much as MWCNT, maintaining the Newtonian behavior even at 1.5 wt.% FGS. MW...
Last. Luigi Torre(University of Perugia)H-Index: 13
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Abstract The use of graphene for the development of a strain and damage sensor was evaluated and modeled. To achieve this, a graphene epoxy reactive mixture was used as a conductive coating which was cured onto a carbon fiber reinforced composite. This methodology proved to be very effective where substantial changes in piezoresistivity (up to 400%) were found as a function of strain (up to 2%). This contributed to a very high linear gauge factor (56.7±0.69). The role of reversible and irreversi...
Last. Trevor M. Young(UL: University of Limerick)H-Index: 20
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Abstract Two-part epoxy paste adhesives are frequently used to bond metals and composite materials in many structural applications. After mixing two reactive parts (by weight or volume ratio), adhesive paste is applied to the substrate surfaces and cured at elevated temperatures. Air-entrapment during mixing and/or application process often produces micro-voids in the adhesive bondlines and influences the strength of the bonded joints. In this work, void formation was investigated using two adhe...
Multicomponent nanocomposite materials based on a high-performance epoxy system and single-walled carbon nanotubes (SWNTs) have been prepared. The noncovalent wrapping of nitric acid-treated SWNTs with a PEO-based amphiphilic block copolymer leads to a highly disaggregated filler with a boosted miscibility in the epoxy matrix, allowing its dispersion without organic solvents. Although direct dispersion of acid-treated SWNTs results in modestly improved epoxy matrix mechanical properties, the inc...
Last. Yiu-Wing Mai(USYD: University of Sydney)H-Index: 112
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A highly ordered poly(dimethyl siloxane)-poly(glycidyl methacrylate) (PDMS-PGMA) reactive diblock copolymer was synthesized and used to modify bisphenol A-type epoxy resin (ER). The PDMS-PGMA block copolymer consisted of epoxy-miscible PGMA blocks and an epoxy-immiscible PDMS block. The PGMA reactive block of the block copolymer formed covalent bonds with cured epoxy and was involved in the network formation, and the PDMS block phase separated to give different ordered and disordered nanostructu...
The ability to control the dispersion of carbon nanotubes in polymers is key to most applications of nanotube-polymer composites. This feature article describes recent advances in methods used to disperse carbon nanotubes and considers how these methods affect dispersion on different length scales. It is becoming increasing clear that perfect dispersion is not desired for many applications, in particular for electrical conductivity, and controlling the dispersion is key for proper function of th...
Last. Suchart Siengchin(King Mongkut's University of Technology North Bangkok)H-Index: 28
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Abstract As one of the goals in recent research and development is to use eco-friendly materials from sustainable resources to manufacture a product material. Bioepoxy resin is a relevant choice to maximize the natural content of the composites along with natural fiber as a reinforcement material. This work presents the effect of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) triblock copolymer in bioepoxy and bioepoxy composites prepared by sisal fibers. Incorpor...
#1Bruna Louise Silva(UDESC: Universidade do Estado de Santa Catarina)H-Index: 2
#2Marcia B. Schuster(UDESC: Universidade do Estado de Santa Catarina)H-Index: 2
Last. Luiz A. F. Coelho(UDESC: Universidade do Estado de Santa Catarina)H-Index: 17
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This work studies the effects of combining triblock copolymers with carbon nanoparticles (carbon nanotubes, graphene and carbon black) on curing kinetics. The chosen triblock copolymer was poly (propylene glycol)-block-poly (ethylene glycol)-block-poly (propylene glycol) (PPG-b-PEG-b-PPG), which has different contents of PEG in its structure. The main objective is to investigate the influence of the miscibility of the PPG-b-PEG-b-PPG copolymer in epoxy nanocomposites. The PEG fraction in the cop...
#2Janusz Datta(GUT: Gdańsk University of Technology)H-Index: 21
Last. Sabu Thomas(Mahatma Gandhi University)H-Index: 114
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Abstract We are utilizing a new method to improve the dielectric properties of a conventional polymer using a recycled polymer product. The polyurethane foams are recycled by glycolysis process and the derived material was applied to improve the dielectric properties of the brittle DGEBA epoxy resin. Two main parameters that determine the applicability of the material as a dielectric (the dielectric constant and dielectric loss), were studied at room temperature for all the blends. The propertie...
#2M. R. Sanjay(King Mongkut's University of Technology North Bangkok)H-Index: 29
Last. Nishar Hameed(Swinburne University of Technology)H-Index: 23
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Abstract Epoxy resin was modified by the incorporation of poly (e-caprolactone)-block-poly (dimethyl siloxane)-block-poly (e-caprolactone) (PCL–PDMS–PCL) triblock copolymer (TBCP) in the presence of 4,4′-diaminodiphenylmethane (DDM). The role of intermolecular hydrogen bonding interaction in cure behavior, morphology, thermo-mechanical and surface wetting properties of TBCP modified epoxy thermoset was investigated. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetr...
We synthesized PPG-terminated tetra-carbamates as a new toughening additive for epoxy thermosets through facile addition reaction of hexamethylene diisocyanate (HDI) with poly(tetra-methylene glycols) (PTMG) and poly(propylene glycols) (PPG). The effects of prepared tetra-carbamates on the rheological behavior of neat epoxy resin were studied along with the various cured properties of their modified epoxy systems. Four carbamate groups (–NHCOO–) endow the prepared additives not only with good in...
Abstract Inspired by the octopus, a typical nanostructure consisting of a spherical “body” and worm-like “tentacles with suckers” was constructed through incorporating polydimethylsiloxane-block-poly(e-caprolactone)-block-polystyrene (BXLS) in epoxy thermosets. The novel nanostructure of BXLS copolymer and its morphology evolution during the epoxy curing process were investigated by transmission electron microscopy, field emission scanning electron microcopy and small-angle X-ray scattering. The...
#1Ping Yu(CAS: Chinese Academy of Sciences)H-Index: 1
#2Guitao Li(CAS: Chinese Academy of Sciences)H-Index: 13
Last. Ga Zhang(CAS: Chinese Academy of Sciences)H-Index: 26
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Abstract Structural evolution and mechanical properties of polyurethane/epoxy interpenetration networks (PU/EP IPNs) as a function of PU content were comprehensively studied. In particular, tribological behaviors of the IPNs were investigated in water medium while varying lubrication regimes. Our results demonstrate that microstructures of PU/EP IPNs are closely dependent on stoichiometric proportions of their components. It is impressive that unlike conventionally modified polymers, blending 30...