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rubber-toughening
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Toughening epoxy resins with solid acrylonitrile-butadiene rubber
, Article Polymer International ; Volume 49, Issue 2 , 2000 , Pages 163-169 ; 09598103 (ISSN) ; Mehrabzadeh, M ; Parvary, M ; Sharif University of Technology
2000
Abstract
The feasibility of using solid acrylonitrile-butadiene rubbers (NBR) with 19 and 33% w/w acrylonitrile to toughen diglycidyl ether of bisphenol A (DGEBA) epoxy resins has been investigated. Thermal analysis experiments revealed a two-phase morphology of these rubber-modified epoxies. However, the higher content of acrylonitrile in the rubber caused better compatibility between NBR and the epoxy resin. The rubber with 33% acrylonitrile was found to be an effective toughening agent for DGEBA epoxy resins. Fracture surface studies and also the high tensile strength of crosslinked high molecular weight NBR suggest that the toughening effect should arise from rubber bridging and tearing...
Preparation of highly rubber-toughened nylons
, Article Iranian Polymer Journal (English Edition) ; Volume 16, Issue 7 , 2007 , Pages 459-468 ; 10261265 (ISSN) ; Yousefi, A. A ; Ramezani saadatabadi, A ; Sharif University of Technology
2007
Abstract
Nylon 6 and 66 were toughened with EPDM-g-MA and SEBS-g-MA and steadystate rheological behaviour of rubbers, nylons and their blends and mechanical properties of nylons and their rubber-toughened blends were investigated. The EPDM maleic grafting preparation was performed In the framework of this study where SEBS-g-MA was obtained from a commercial source. The results showed the ultratoughened SEBS-g-MA blends, whereas EPDM blends under the same blending conditions did not show a significant improvement in toughness. In case of EPDM toughened blends an average of some micrometers was observed for the dispersed EPDM particles. Impact and tensile properties of the toughened blend with 20% of...
Rubber-toughened epoxies: A critical review
, Article Polymer Reviews ; Volume 49, Issue 3 , 2009 , Pages 201-225 ; 15583724 (ISSN) ; Marouf, B. T ; Pearson, R. A
2009
Abstract
Epoxy resins have been used as structural materials since the late 1940s. Despite their desirable properties such as high strength, excellent creep resistance, and good adhesion, they suffer from low fracture energy. Rubber modification as a major toughening approach to overcome the inherent brittleness of epoxy polymers was introduced during the early 1970s. Since then, a large number of investigations have been conducted to elucidate different aspects of rubber-toughened epoxies. The present work is a critical review of the field focusing on the important parameters affecting rubber-toughening. The studies reviewed are classified in five categories including roles of matrix ductility,...
Preparation and Structureproperties Relationship in Rubber Toughened PA6 Reinforced with Nanodiamond
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
Polyamide6 has many engineering applications due to its physical, mechanical and processability properties. However, its low impact resistance limits the use of polyamide6. One of the common ways to overcome this problem and extend the range of polyamide6 application is its elasticity with elastomeric materials, which reduces the strength and modulus (tensile and flexure) in comparision with neat polyamide6. To overcome this limitation, various reinforcements, often fiber or particle-shaped, are used. Today, with the development of nanoparticles, this effort is being made to use nanoparticles, especially carbon nanoparticles with unique properties. Recent research has shown that the addition...
Manufacturing and Mechanical Properties and Microstructure Optimization of the Ternary Polypropylene-based Composite Reinforced by Short Flax Fibers and Toughened by Poe Rubber Particles
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Seyed Reyhani, Morteza (Supervisor)
Abstract
Recently, Polypropylene has been extensively used in a variety of applications in the polymer industry, but its quite low stiffness and toughness limit this polyolefin’s application in the engineering functions; thus, the market of polymer blend and composite manufacturing has grown noticeably in the last few years. In the current project, short Flax fibers are used in order to reinforce the PP matrix. Firstly, Flax fibers were washed with the gentle and harsh condition during the alkalization process, then the optimized alkalization condition was determined through comparison of results from X-ray Diffraction (XRD ), Attenuated Total Reflectance FTIR (ATR-FTIR) and microscopic surface...
Fabrication and Study of Mechanical Behavior of in Situ Microfibrillar- Reinforced Composites of Polypropylene/Recycled Poly (Ethylene Terephthalate)Toughened with Rubber Particles
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Alizadeh, Reza (Supervisor)
Abstract
The use of polymers is increasing day by day due to low density, reasonable price and ability to produce different products. On the other hand, the accumulation of polymer wastes in nature is one of the environmental concerns in today's world, which is mainly due to the widespread use of polymers in the packaging industry and disposable applications. In order to solve this problem, recycling is recommended as the most appropriate and economical solution. Because in addition to consuming polymer waste, it also saves energy and reduces carbon footprint.Polyethylene terephthalate (PET) is one of the polymeric materials which; It has a special place in the packaging industry and is widely used...
Fracture toughness of a hybrid rubber modified epoxy. II. Effect of loading rate
, Article Journal of Applied Polymer Science ; Volume 125, Issue 3 , January , 2012 , Pages 2476-2483 ; 00218995 (ISSN) ; Kouchakzadeh, M. A ; Bagheri, R ; Sharif University of Technology
Wiley
2012
Abstract
Effect of loading rate on toughness characteristics of hybrid rubber-modified epoxy was investigated. Epoxy was modified by amine-terminated butadiene acrylonitrile (ATBN) and recycled tire. Samples were tested at various loading rates of 1-1000 mm/min. Fracture toughness measurements revealed synergistic toughening in hybrid system at low loading rates (1-10 mm/min); hybrid system exhibited higher fracture toughness value in comparison with the ATBN-modified resin with same modifier content. However, synergistic toughening was eliminated by increasing the loading rate. At higher loading rates (10-1000), the fracture toughness of hybrid system decreased gradually to the level lower than that...
The simultaneous effect of silica nanoparticles and rubber particles on the toughness of epoxy polymer
, Article International Journal of Nanomanufacturing ; Volume 5, Issue 3-4 , 2010 , Pages 232-244 ; 17469392 (ISSN) ; Bagheri, R ; Sharif University of Technology
2010
Abstract
The objective of this study is to investigate the effects of both rubbery phase and nanosilica on mechanical properties of epoxy. Three series of formulations based on epoxy including nanosilica, rubber and rubber/nanosilica were prepared. Transmission electron microscopy showed that nanoparticles were homogeneously dispersed throughout the epoxy matrix. Compression and fracture toughness tests along with scanning electron microscopy and transmission optical microscopy were also done to evaluate the properties of the compounds. Although the results of compression tests indicate that addition of nanosilica could not change elastic modulus and yield strength of neat resin significantly,...
Investigation of the fracture resistance in hoop wound composites modified with two different reactive oligomers
, Article Materials and Design ; Volume 30, Issue 8 , 2009 , Pages 3048-3055 ; 02641275 (ISSN) ; Bagheri, R ; Haddadpour, H ; Motamedi, P ; Sharif University of Technology
2009
Abstract
Rubber modification of hoop filament wound epoxy composites was investigated using amine-terminated butadiene acrylonitrile (ATBN) and carboxyl-terminated butadiene acrylonitrile (CTBN) oligomers. Both mechanical and physical properties of modified composites were investigated and the morphology of the samples was studied via scanning electron microscopy. Results indicated that, when added to the epoxy matrix, ATBN effected a superior increase in toughness, yet a more severe decline in compressive and flexural strength, compared to CTBN. In contrast, in the case of composite samples, incorporation of ATBN led to more favorable mechanical properties, from the viewpoint of both toughness and...
Anomalous fracture behavior in an epoxy-based hybrid composite
, Article Materials Science and Engineering A ; Volume 515, Issue 1-2 , 2009 , Pages 49-58 ; 09215093 (ISSN) ; Pearson, R. A ; Bagheri, R ; Sharif University of Technology
2009
Abstract
In this investigation, core-shell rubber particles and organically modified clay were added to an epoxy resin and the changes in mechanical behavior were studied. As expected, the yield strength of the organoclay-filled epoxies increased modestly with increasing clay content and the yield strength of the rubber-modified compounds decreased with rubber content. Interestingly, the compressive yield strength of epoxy resins containing both rubber particles and organoclay (a.k.a. hybrid nanocomposites) was found to be independent on organoclay content (up to 5 phr). The fracture toughness of organoclay-filled epoxies increased modestly with clay content and, as expected, the increases in...
Use of rubber modification technique to improve fracture-resistance of hoop wound composites
, Article Materials and Design ; Volume 30, Issue 6 , 2009 , Pages 1976-1984 ; 02641275 (ISSN) ; Khademi, V ; Bagheri, R ; Haddadpour, H ; Kouchakzadeh, M. A ; Farsadi, M ; Sharif University of Technology
2009
Abstract
Toughness improvement of an epoxy resin and respective hoop wound composite were investigated systematically using amine-terminated butadiene acrylonitrile (ATBN) liquid rubber. Rubber modification improves fracture toughness of epoxy resin with slight reduction in the glass transition temperature (Tg), flexural and compressive properties of resin. Impact resistance of composite is improved by rubber modification similar to modified resin. Interlaminar shear strength (ILSS), compressive modulus and strength, and flexural strength of composite decreased slightly with rubber modification. To interpret the data, the void content of composite samples was determined and the damaged surfaces of...
Taguchi analysis of extrusion variables and composition effects on the morphology and mechanical properties of EPR-g-MA toughened polyamide 6 and its composite with short glass fiber
, Article Materials Science and Engineering A ; Volume 506, Issue 1-2 , 2009 , Pages 45-57 ; 09215093 (ISSN) ; Fereydoon, M ; Sharif University of Technology
2009
Abstract
Various compositions of maleated ethylene-propylene-rubber (EPR-g-MA) toughened polyamide 6 without and with short glass fiber, i.e. 5-20 wt.% rubber and 5-20 wt.% fiber, are prepared using an industrial twin-screw extruder at different levels of feed rate (100-250 kg/h), screw speed (200-450 rpm) and barrel temperature (230-260 °C). Trial runs designed based on the Taguchi's orthogonal arrays are subjected to tensile, impact, scanning electron microscopy (SEM) and optical microscopy tests; and the results are used to perform the analysis of variance (ANOVA). It is shown that the rubber particle size decreases significantly by increasing the rubber content for the unreinforced blend. The...