Showing papers in "Polymer-plastics Technology and Engineering in 2010"
TL;DR: In this article, the authors proposed a method for converting epoxidized vegetable oils (EVO) into useful polymerizable oxygenated monomers commonly by Prileshajev-epoxidation, catalytic epoxidation using acidic ion exchange resin, chemo-enzymatic epoxide, or metal-catalyzed epoxide.
Abstract: Epoxidized vegetable oils (EVO) have drawn much attention in recent years, especially in the polymer industry as they are economical, available, environmentally friendly, non-noxious and renewable. Vegetable oils can be transformed into useful polymerizable oxygenated monomers commonly by Prileshajev-epoxidation, catalytic epoxidation using acidic ion exchange resin, chemo-enzymatic epoxidation, or metal-catalyzed epoxidation. Among those epoxidation methods, chemo-enzymatic epoxidation has achieved considerable interest nowadays since this method is safe, environmentally friendly and conversion rate of epoxidation usually exceeds 90%. Bio-based epoxidized vegetable oils from renewable natural resources are potential green materials to partially substitute and toughen petrochemical-based polymers.
261 citations
TL;DR: In this paper, the authors reviewed the mechanism of the conducting process of carbon nanotubes (CNTs)-reinforced polymer nanocomposites and discussed the critical factors that determine percolation thresholds or the conductivity of the nanocomposition.
Abstract: This paper reviews the mechanism of the conducting process of carbon nanotubes (CNTs)-reinforced polymer nanocomposites. Comparison of the two different mechanisms, the formation of the conducting network and the hopping of the electrons, are discussed. The paper also describes the critical factors that determine percolation thresholds or the conductivity of the nanocomposites. By summarizing the predecessors' research, some measures are put forward to improve the structure of the nanocomposites to get the samples that have the most extraordinary electrical conductivity with the lowest CNTs concentrations.
126 citations
TL;DR: In this article, Starch-based biodegradable banocomposites of poly(butylene adipate-co-terephthalate) [PBAT] and organically modified nanoclays were prepared using melt intercalation technique in Haake Torque Rheocord 9000.
Abstract: Starch-based biodegradable banocomposites of poly(butylene adipate-co-terephthalate) [PBAT] and organically modified nanoclays were prepared using melt intercalation technique in Haake Torque Rheocord 9000. Two different organically modified nanoclays Cloisite C20A and Cloisite C30B at various wt% (1, 3, 5) have been used for fabrication of nanocomposites. Starch was gelatinized to prepare thermoplastic starch (TPS) for increasing the compatibility with the PBAT matrix. Subsequently, films of PBAT/TPS blends at various TPS contents (10, 20, 30, 40) wt% and PBAT/TPS Organoclay biodegradable blend nanocomposites at different wt% of nanoclays were prepared using solvent casting method. The interfacial region between the biodegradable polymer matrix and the clays were also modified with grafting of Maleic anhydride (MA) with PBAT chains, during melt blending through two stage reactive extrusion process. Mechanical tests revealed an increase in tensile modulus and elongation at break with the incorporation of ...
94 citations
TL;DR: In this article, a study on the preparation and characterizations of Pine Needles reinforced polymers using Phenol-Formaldehyde (PF) as a novel polymer matrix has been reported.
Abstract: In the present communication a study on the preparation and characterizations of Pine Needles (PN) reinforced polymers using Phenol-Formaldehyde (PF) as a novel polymer matrix has been reported Pine Needles (PN) of different dimensions were used to prepare biocomposites The influence of different fiber dimension on the mechanical properties of the composites was determined Analysis of morphological (SEM) and thermal (TGA/DTA) properties of Pine Needles, PF resin and polymer composites have also been carried out These polymer composites were further subjected to various standardized characterization tests such as swelling under different solvents, moisture absorption and chemical resistance analysis
92 citations
TL;DR: In this paper, the influence of type of modified clay on surface properties of the resultant nanocomposite was investigated by various analytic techniques, namely, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurement (CAM), scanning electron microscopy(SEM), and reflectance spectrography (RS).
Abstract: Poly ethylene terephthalate (PET)-based nanocomposites containing three differently modified clays were prepared by melt compounding. The influence of type of modified clay on surface properties of the resultant nanocomposite was investigated by various analytic techniques, namely, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurement (CAM), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). Any possible interaction between each nanoclay and PET at the surface was elucidated by Fourier transform infrared spectroscopy. Atomic force microscopy studies of the resultant nanocomposites showed increased in surface roughness compared to pure PET. Contact angle measurements on the resultant PET composites demonstrated that the wettability of such composites depends on hydrophilicity of the nanoclay particles. Scanning electron microscopy images illustrated poor interfacial interaction between PET and Na+ clay particles causing fracture type non...
85 citations
TL;DR: In this paper, the authors investigated the weldability of UHMW-polyethylene via friction stir welding method and obtained a tensile test, durometer hardness test and an optical microstructure analysis were conducted on welded joint.
Abstract: The aim of this study was to investigate the weldability of UHMW-polyethylene via friction stir welding method. The samples were joined with single pass under 960–1960 rpm rotational speeds and 10–20 mm/min transverse speeds. In this study, three different heating processes were used. These processes are welding at room temperature, welding by pre-heating from the bottom of plastic samples at 50°C and 80°C with metal molding. A tensile test, durometer hardness test and an optical microstructure analysis were conducted on welded joint. In the experiments, a tensile strength of 72% was achieved in non-preheated welds whereas tensile strength of parent material was achieved approximately at an optimum value of 89% by pre-heating at 50°C. Pre-heating process enabled a homogeneous heat distribution by approximating the plastic material to fusing point in a short time and facilitated mixing and as a result welded joint of a supremer characteristic was obtained.
82 citations
TL;DR: In this article, the electrospinning process, along with its modeling equations and applications have been discussed, and some typical case studies regarding electro-spinning under various categories have also been discussed.
Abstract: Although there are several methods for obtaining sub-micro or nanofibers, electrospinning is perhaps the most versatile process. Nanotechnology has been widely accepted as dealing with the science and technology where at least one dimension is of roughly 1 to 100 nm. Electrospinning has been recognized as a feasible technique for the fabrication of polymeric nanofiber yarns. Various materials including polymers, composites, ceramics and metals have been electrospun into nanofibers. The nanofibers thus produced exhibit novel and significantly improved physical, chemical and biological properties due to their nanolevel size. In this article, the electrospinning process, along with its modeling equations and applications have been discussed. Some typical case studies regarding electrospinning under various categories have also been discussed.
81 citations
TL;DR: In this article, the photocatalytic degradation of polyethylene (PE) plastic was carried out directly under the sunlight irradiation with polypyrrole/TiO2 (PPy/ TiO2) nanocomposite as photocatalyst, which prepared by solgel and emulsion polymerization methods.
Abstract: The photocatalytic degradation of polyethylene (PE) plastic was carried out directly under the sunlight irradiation with polypyrrole/TiO2 (PPy/TiO2) nanocomposite as photocatalyst, which prepared by sol-gel and emulsion polymerization methods. The photocatalytic degradation efficiency was determined by weight loss monitoring, gel permeation chromatography (GPC), atomic force microscopic (AFM) and FT-IR analysis. The photocatalytic degradations of PE plastic with pure TiO2 and PPy were also investigated and compared with that of PPy/TiO2. It was noticed that irradiating the PE plastic for 240 h by sunlight reduced its weight up to 35.4% and 54.4% of M w, respectively. The AFM images showed the formation of cavities on PE plastic surface. FT–IR spectroscopic studies indicated that a strong interaction existed between the interface of PE and PPy/TiO2 and caused the degradation of PE. The photocatalytic degradation mechanism was also discussed briefly.
72 citations
TL;DR: In this paper, polyethersulfone (PES) was sulfonated using chlorosulfonic acid in order to improve proton conductivity, and incorporation of SO3H groups into polymer main chain through sulfonation was confirmed using FTIR and 1H NMR.
Abstract: Polyethersulfone (PES) was sulfonated using chlorosulfonic acid in order to improve proton conductivity. Incorporation of ‒SO3H groups into polymer main chain through sulfonation was confirmed using FTIR and 1H NMR. Ion exchange capacity of sulfonated membranes was determined via titration. Morphological studies (AFM, SEM) revealed the presence of hydrophilic proton transfer channels, which became continuous at higher degrees of sulfonation. Thermal stability was observed from thermogravimetric analysis (TGA). Storage modulus and tan δ also exhibited an increase with degree of sulfonation as determined from DMA. Conductivity measurements and fuel cell performance showed that sulfonated samples possessed higher conductivity than virgin PES.
69 citations
TL;DR: In this paper, various thermally conductive fillers including aluminum oxide(Al2O3), magnesium oxide(MgO), β-silicon carbide particle(β-SiCp), and βsilicon carbon carbide whisker(β -SiCw) were used to prepare polystyrene thermal conductivity composites.
Abstract: Various thermally conductive fillers including aluminum oxide(Al2O3), magnesium oxide(MgO), β-silicon carbide particle(β-SiCp) and β-silicon carbide whisker(β-SiCw) were used to prepare polystyrene thermal conductivity composites. Experimental results showed that, for given filler loading, the thermal conductivity of the composites was higher for PS flake than that of PS particle, and the thermal conductivity was optimal by powder blending method. The SiCw filler was more favorable to improve the thermal conductivity of the composites; a much higher thermal conductivity of 1.18 W/mK could be achieved for the composite with 40 vol% SiCw, about six times higher than that of native polystyrene. The experimental thermal conductivity values were in agreement with those predicted by lower bound of Maxwell-Eueken model. For given SiC loading, the thermal conductivity increased with the increasing shape parameter of n. The SiCw was much easier to form the thermal conductivity chains and network than that of SiCp.
61 citations
TL;DR: In this article, a biodegradable film based on gelatin and Na+Montmorillonite was prepared by mixing of gelatin solutions with ultrasonically pre-treated clay suspensions under controlled conditions.
Abstract: Biodegradable films based on gelatin and Na+-Montmorillonite were prepared by mixing of gelatin solutions with ultrasonically pre-treated clay suspensions under controlled conditions. The DRX patterns and AFM images suggested that ultrasonication process resulted in homogeneously distributed layered silicates inside the matrix but not fully exfoliated. Transparency was retained, suggesting that filler is mostly distributed at the nanoscale. The results of DMA showed an improvement in storage modulus and shifts in tan δ peaks toward higher temperatures. The reduction in polar groups due to hydrogen interactions between gelatin and clay particles was evidenced by the decrease in surface hydrophilicity and WVP.
TL;DR: In this article, an anhydride/epoxy ratio (R) was found to have significant effect on the resulting properties of the bio-based epoxy materials and compared by dynamic mechanical analysis (DMA), izod impact, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).
Abstract: Bio-based epoxy materials were prepared from epoxidized soybean oil (ESO) with an anhydride-curing agent. Variation of anhydride/epoxy ratio (R) was found to have significant effect on the resulting properties of the materials. The properties were studied and compared by dynamic mechanical analysis (DMA), izod impact, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The glass transition temperature reaches the maximum at stoichiometric ratio related to the cross-link density of the formed networks. These materials are thermally stable but exhibit a rapid decrease as the anhydride/epoxy ratio was increased.
TL;DR: In this article, the tensile properties and fatigue life of NR/MWCNT were enhanced by incorporating MWCNT at different loading using two different methods, i.e., mechanical and solution mixing.
Abstract: The NR/MWCNT nanocomposites were prepared by incorporation of MWCNT at different loading using two different methods, i.e., mechanical and solution mixing. For NR/MWCNT that prepared by mechanical mixing method, the results show that the scorch and cure time decrease with increasing MWCNT loading. The tensile modulus increase with increasing MWCNT loading but decrease the tensile strength, fatigue life and elongation at break. The SEM results show there is a lot of agglomeration of MWCNT occurred. Using the solution mixing method, the MWCNT are well dispersed in the natural rubber matrix and the tensile properties and fatigue life of NR/MWCNT were enhanced.
TL;DR: In this paper, the effect of polyethylene-grafted maleic anhydride (PE-g-MAH) on the tensile properties, morphology and thermal properties of low-density polyethylenes (LDPE)/eggshell powder (ESP) composites was studied.
Abstract: The effect of polyethylene-grafted maleic anhydride (PE-g-MAH) on the tensile properties, morphology and thermal properties of low-density polyethylene (LDPE)/eggshell powder (ESP) composites was studied. LDPE/ESP composites with different eggshell powder content and the addition of PE-g-MAH were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The tensile strength, elongation at break and thermal stability of LDPE/ESP composites with PE-g-MAH were greater than LDPE/ESP composites, and their differences became more pronounced at higher filler content. The interfacial adhesion between ESP and LDPE was improved with the addition of PE-g-MAH as evidenced by the morphological study.
TL;DR: In this article, the fracture toughness and thermal properties of epoxy/EPO blends were characterized using single-edge notched bending tests and differential scanning calorimetry, and it was determined that the water molecules absorbed were totally reversible.
Abstract: Epoxidized palm oil (EPO) was blended with cycloaliphatic epoxide, epoxy novolac and diglycidyl ethers of bisphenol-A. The fracture toughness and thermal properties of epoxy/EPO blends were characterized using single-edge notched bending tests and differential scanning calorimetry. Increased EPO loading improved the fracture toughness (K IC ) of the epoxy blends. The epoxy blends with higher EPO loading exhibited higher degree of conversion. The glass transition temperature (T g ) of the epoxy blends shifted to higher temperature as the increasing of DSC heating rate. Water absorption caused T g reduction of epoxy blends but it was determined that the water molecules absorbed were totally reversible.
TL;DR: In this article, differentially scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were performed to study various thermal properties of the chitosan biocomposites.
Abstract: Kenaf filled chitosan biocomposites have been prepared via solution blending method. 0.1 M acetic acid was used as diluent. Five types of biocomposites with different compositions of kenaf fiber by weight designated as (CH, CH7, CH14, CH21, and CH28) were prepared. Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) were performed to study various thermal properties of the biocomposites. It was found that the biocomposites have undergone several decomposition stages over a range of temperatures as revealed by TGA thermograms, with CH exhibited highest mass loss as compared to other composites. From the DSC thermogram, incorporation of kenaf dust into chitosan has reduced the thermal stability of the chitosan film. The reduction is proportionate to the amount of kenaf dust added and was attributed to the formation of inter- and intrahydrogen bonding between amine groups of chitosan matrix and hydroxyl methyl groups of kenaf fiber.
TL;DR: In this paper, TPNR hybrid composite with kenaf/glass fibers was prepared with fiber content (5, 10, 15, 20 volume % of fiber). Mechanical properties of the composites were investigated using tensile test, impact, and hardness test and scanning electron microscope (SEM).
Abstract: Thermoplastic natural rubber hybrid composites reinforced with kenaf and short glass fibers were compounded by melt blending method using an internal mixer, Thermo Haake 600P. Thermoplastic natural rubbers (TPNR) were prepared from polypropylene (PP), natural rubber (NR) and liquid natural rubber (TPNR) with ratio 70:20:10, which were blended using internal mixer for 12 minutes at 180°C and rotor speed 40 r.p.m. Glass fiber was treated with silane coupling agent while TPNR reinforced kenaf fiber composite is using MAPP as a compatibilizer. TPNR hybrid composite with kenaf/glass fibers was prepared with fiber content (5, 10, 15, 20 volume % of fiber). Mechanical properties of the composites were investigated using tensile test[ 1 ], flexural, impact, and hardness test and scanning electron microscope (SEM)[ 1 ]. The incorporation of the treated or untreated fiber into TPNR has result in an increment of almost 100% of flexural modulus and impact strength as compared to TPNR matrix. However, the maximum stra...
TL;DR: In this paper, the morphology and properties of PMMA-clay (1.5phr) nanocomposites prepared by three different manufacturing techniques viz., solution mixing, melt mixing, and suspension polymerization have been investigated.
Abstract: The morphology and properties of PMMA-clay (1.5 phr) nanocomposites prepared by three different manufacturing techniques viz., solution mixing, melt mixing, and suspension polymerization, have been investigated. XRD study revealed that for particular clay loading, the extent of clay intercalation by the PMMA chains depend on the manufacturing techniques. The glass transition temperature of PMMA increased significantly in the in-situ polymerized PMMA-clay nanocomposites. TGA results revealed nearly 14% improvement in thermal stability of PMMA for in-situ polymerized PMMA-clay nanocomposite. In both the glassy and rubbery regions, the storage moduli of all the nanocomposites were higher than that of neat PMMA.
TL;DR: In this paper, the feasibility of a strategy to partially replace polyamide-6 (PA6) with poly(lactic acid) (PLA), the morphology, mechanical, and thermal properties of PA6/PLA blending systems were investigated.
Abstract: To evaluate the feasibility of a strategy to partially replace polyamide-6 (PA6) with poly(lactic acid) (PLA), the morphology, mechanical, and thermal properties of PA6/PLA blending systems were investigated. Polyethylene-octene elastomer (POE) and POE grafted with maleic anhydride (POE-g-MAH) are added to improve the impact strength and elongation at break of the blend. The results show that POE-g-MAH is an effective compatibilizer for PA6/PLA blending system. Compared with the morphology of PA6/PLA/POE, smaller particle size, more homogeneous distribution of domains and improved interfacial adhesion between matrix and domains were observed in the PA6/PLA/POE-g-MAH blending system.
TL;DR: In this paper, non-cross-linked and cross-linked polyvinyl alcohol (PVA) films were prepared by the casting method then irradiated with gamma rays for various doses up to 300kGy.
Abstract: The non-cross-linked and cross-linked polyvinyl alcohol (PVA) films were prepared by the casting method then irradiated with gamma rays for various doses up to 300 kGy. The structure and characterization of PVA were determined by using Infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and X-ray diffraction (XRD). Swelling behaviour was also investigated. Mechanical properties have been examined with respect to the absorbed dose. The color of the films changed to yellowish-white after irradiation and the crystallinity of the films decreased with increasing dose. Additional changes observed by FTIR analysis of the degradation products demonstrated that the radiolysis of PVA was initiated by liberation of H and OH groups leading to scission of the main chains and formation of carbonyl and double bond groups. Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were performed. The FTIR, UV, XRD and mechanical properties indicate that the addition of cross-linker led to high degree...
TL;DR: In this paper, the synthesis and characterization of Grewia Optiva fiber reinforced Phenol-Formaldehyde (PF) matrix-based polymer composites through compression molded technique have been reported.
Abstract: In present communication, synthesis and characterization of Grewia Optiva fiber reinforced Phenol-Formaldehyde (PF) matrix-based polymer composites through compression molded technique have been reported. The work carried out reveals that mechanical properties of the PF resin increases to extensive extent when reinforced with Grewia Optiva fibers. Thermal (TGA/DTA/DTG) and morphological studies (SEM) of polymer composites thus synthesized have also been carried out to access the applications of polymer composite materials in daily life.
TL;DR: In this article, the effect of silane treatments on the water absorption properties of bamboo matting reinforced epoxy composites were investigated, and it was found that among the various silanes used only aminopropyltriethoxy silane treatment is suitable for bamboo-epoxy composite.
Abstract: The effect of silane treatments on the water absorption properties of bamboo matting reinforced epoxy composites were investigated. Treatments using γ-Aminopropyltriethoxy silane, 3-trimethoxysilylpropyl methacrylate, Vinyltris(2-methoxyethoxy)silane, Bis[3-(triethoxysilyl)propyl] tetrasulfide, 3-aminopropyltrimethoxy silane and n-Octyltrimethoxy silane were carried out to study the water absorption property of the bamboo composites. Water absorption in the composites was studied by long-term immersion and 2 h boiling in distilled water. The process of absorption of water was found to follow the kinetics and mechanism described by Fick's theory. Only aminosilanes have shown the positive effects, but to a limited degree. It has been found that among the various silanes used only aminopropyltriethoxy silane treatment is suitable for bamboo-epoxy composite. Aminopropyltriethoxy silane-treated bamboo fiber composite has decreased the water uptake from 41.42% to 36.87%.
TL;DR: In this paper, mixed acid was used to purify multi-walled carbon nanotubes, and a silane coupling agent n-octyltriethoxysilane (OTES) was added to the mixture to modify them.
Abstract: This experiment adopted mixed acid (H2SO4:HNO3 = 3:1) to purify multi-walled carbon nanotubes, and used a silane coupling agent n-octyltriethoxysilane (OTES) to modify carbon nanotubes, respectively. Then we mixed OTES-modified carbon nanotubes (CNTs) with high-density polyethylene (HDPE) resin to make a composite. TGA analysis results revealed that as the CNTs'content increased, the Td10 tended to rise. The amount of composite residual at 500°C also increased, as well as the composite electrical conductivity. When a concentration of 5% OTES was used to modify the CNT, the resultant composite exhibited better electrical conductivity.
TL;DR: In this paper, maleic anhydride (MA) was first grafted onto BC nanofibers to improve the compatibility of the composites and the tensile strength and modulus increased.
Abstract: Nanocomposite consisting of two biocompatible materials, bacterial cellulose (BC) and polylactide was prepared. To improve the compatibility, maleic anhydride (MA) was first grafted onto BC nanofibers. Mechanical tests showed that the tensile strength and modulus of the composites increased, especially the composites including BC nanofibers modified with MA. Differential scanning calorimetry showed the thermal behaviors changed due to the addition of BC. The morphology of the composites suggested that the grafting of MA made BC nanofibers well disperse into polylactide matrix and the interfacial adhesion between BC and polylactide was improved. This research proposes novel avenues to tailor the dispersion of BC nanofibers into the thermoplastic matrix to produce nanocomposites and improve the compatibility of reinforcement and matrix.
TL;DR: The addition of the organoclay into the PBS/PBAT blends produced intercalated-type nanocomposites with improvements in tensile modulus and strength as mentioned in this paper.
Abstract: Sodium montmorillonite (Na-MMT) was successfully modified by octadecylamine (ODA) through a cation exchange technique that showed by the increased of basal spacing of clay by XRD. The addition of the organoclay into the PBS/PBAT blends produced intercalated-type nanocomposites with improvements in tensile modulus and strength. The highest tensile strength of nanocomposite was observed at 1 wt% of organoclay incorporated. A TGA study showed that the thermal stability of the blend increased after the addition of the organoclay by 1 wt%. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes smoother with presence of organoclay.
TL;DR: In this article, low density polyethylene (LDPE)/modified water hyacinth fiber (WHF) composites have been prepared by melt blending, and all the composites were characterized by tensile test, differential scanning calorimetry (DSC), water absorption behaviour, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).
Abstract: Low density polyethylene (LDPE)/modified water hyacinth fiber (WHF) composites have been prepared by melt blending. All the composites were characterized by tensile test, differential scanning calorimetry (DSC), water absorption behaviour, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results indicated that LDPE/WHF composites with NCO-polyol as a coupling agent show higher values of tensile strength, Young's modulus and water absorption resistance but lower elongation at break than LDPE/WHF composites without NCO-polyol. The micrographs of SEM showed that the WHF were more widely dispersed in the LDPE matrix with the addition of the NCO-polyol as a coupling agent. It was also found that the modified WHF offers better thermal stability in the LDPE/WHF composites than unmodified WHF.
TL;DR: In this paper, the effects of electron beam irradiation of (ethylene vinyl acetate) EVA containing 18% vinyl acyclic acid (VVA) was studied.
Abstract: The effects of electron beam irradiation of (ethylene vinyl acetate) EVA containing 18% vinyl acetate was studied. The EVA sample was then irradiated by using 3 MeV electron beam machine at doses ranging from 120 to 360 kGy in air at room temperature and analyzed for mechanical, thermal and electrical properties. It was revealed by DSC analysis that the crystallinity of the electron-beam radiated EVA decreased slightly as verified by a marginal reduction in the densities and heats of melting. Thermal degradation of EVA occurred through two steps as shown by the thermogravimetric curve with maximum rates of 350 and 450°C, respectively. The results obtained from both gel content and hot set tests showed that under the irradiation conditions employed, the EVA sample cross-linked by the electron beam irradiation, and the degree of cross-linking in the amorphous regions was dependent on the irradiation dose. A significant improvement in the tensile strength of the neat EVA samples was obtained upon electron-be...
TL;DR: In this paper, a hand lay-up technique at 150°C under 27.58 MPa pressure for 6 hours by using phthalic anhydride as a curing agent was used.
Abstract: Glass-PA (EC-G-PA), Jute-PA (EC-J-PA), Glass-Jute-Glass (EC-GJG-PA), Jute-Glass-Jute (EC-JGJ-PA) composites of epoxy resin of bisphenol-C (EBC) have been prepared using a hand lay-up technique at 150°C under 27.58 MPa pressure for 6 h by using phthalic anhydride as a curing agent. EC-G-PA, EC-J-PA EC-GJG-PA and EC-JGJ-PA Possess 34, 41, 27 and 21 MPa tensile strength; 34, 27, 19 and 22 MPa flexural strength; 1.9, 1.0, 1.6 and 1.3 kV/mm electric strength and 4.2 × 1013, 1.2 × 109, 8.7 × 1011 and 4.0 × 1011 ohm.cm volume resistivity. Hydrolytic stability of the composites was tested against water, 10% aq. HCl and NaCl solutions at 35°C and also in boiling water. The percent water uptake, equilibrium time and diffusivity of the composites have been determined and discussed their possible applications.
TL;DR: In this article, natural rubber compounds with untreated and treated kenaf were prepared with different loading i.e., 0, 10, 20, 30 and 40 pphr. The compounds were cured at 150°C according to its cure time, t90.
Abstract: Natural rubber compounds with untreated and treated kenaf were prepared with different loading i.e., 0, 10, 20, 30 and 40 phr. The compounds were cured at 150°C according to its cure time, t90. Curing characteristics, tensile properties, rubber-filler interaction and morphology properties of the rubber compounds were tested. Curing characteristics showed that scorch time, ts2 and cure time, t90 decreased with increasing of fibre loading and treatment. Mechanical properties of kenaf filled natural rubber compounds decreased with increasing of fibre loading but increased with fibre treatment. Swelling measurement and morphological study showed that better rubber-filler interaction was obtained with treated kenaf.
TL;DR: In this paper, the results of the processing of nanocomposites based on epoxy and nanofillers, namely multiwalled carbon nanotubes and carbon black, were presented.
Abstract: This paper presents results of the processing of nanocomposites based on epoxy and nanofillers, namely multiwalled carbon nanotubes (up to 10 wt%) and carbon black (up to 15 wt%). The twin screw extruded nanocomposites showed increases in electrical and thermal conductivities, tensile strength, microhardness and glass transition temperature. Electrical conductivity increased on the order of 1011 at 10 wt% of nanotubes loading and at 15 wt% of carbon black. Greater increases in thermal and mechanical properties were observed in cases of nanotube-dispersed composites more so than others. SEM and AFM were used to examine the dispersion of the fillers.