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1.
Partially epoxidized soybean oil (pESO) and fully epoxidized soybean oil (fESO) were used respectively to modify a diglycidyl ether of bisphenol A (DGEBA) resin system in this study. The pESO was prepared by epoxidizing soybean oil and the fESO was purchased as it was commercially available. DGEBA/ESO ratio of the epoxy resin system was changed from 100/0 to 70/30 and triethylenetetramine was used as a curing agent. Impact strength of the bio-epoxy resin system with fESO increased with ESO content, but the system with pESO decreased with ESO content. The bio-epoxy resin system with pESO showed higher tensile strength and elongation at break than the system with fESO at ESO 30 wt%. Tensile modulus and thermal degradation temperature decreased with ESO content and glass transition temperature was highest at 20 wt% ESO regardless of epoxide functionality of ESO. The performance of the DGEBA/ESO bio-epoxy resin system could be tailored by changing ESO content and functionality. 相似文献
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Study on the effect of woven sisal fiber mat on mechanical and viscoelastic properties of petroleum based epoxy and bioresin modified toughened epoxy network 下载免费PDF全文
Sisal fiber reinforced biocomposites are developed using both unmodified petrol based epoxy and bioresin modified epoxy as base matrix. Two bioresins, epoxidized soybean oil and epoxy methyl soyate (EMS) are used to modify the epoxy matrix for effective toughening and subsequently two layers of sisal fiber mat are incorporated to improve the mechanical and thermomechanical properties. Higher strength and modulus of the EMS modified epoxy composites reveals good interfacial bonding of matrix with the fibers. Fracture toughness parameters KIC and GIC are determined and found to be enhanced significantly. Notched impact strength is found to be higher for unmodified epoxy composite, whereas elongation at break is found to be much higher for modified epoxy blend. Dynamic mechanical analysis shows an improvement in the storage modulus for bioresin toughened composites on the account stiffness imparted by fibers. Loss modulus is found to be higher for EMS modified epoxy composite because of strong fiber–matrix interfacial bonding. Loss tangent curves show a strong influence of bioresin on damping behavior of epoxy composite. Strong fiber–matrix interface is found in modified epoxy composite by scanning electron microscopic analysis. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42699. 相似文献
3.
《国际聚合物材料杂志》2012,61(6):385-398
ABSTRACT Unmodified epoxy resins based on bisphenol A exhibit brittleness and low elongation after cure. This article reports the results of a study for improving the properties of epoxy resin by blending with suitable thermosets. Hybrid polymer networks of diglycidyl ether of bisphenol A (DGEBA) resin with epoxidized phenolic novolac resins (EPN) containing phenol and formaldehyde in different stoichiometric ratios were prepared by physical blending. The modified epoxy resins were found to exhibit improved mechanical and thermal properties compared to the neat resin. DGEBA resins containing 2.5 to 20 wt% of epoxidized novolac resins (EPN) prepared in various stoichiometric ratios (1:0.6, 1:0.7, 1:08, and 1:0.9) between phenol and formaldehyde were cured using a room temperature amine hardener. The cured samples were tested for mechanical properties such as tensile strength, modulus, elongation, and energy absorption at break. All the EPNs are seen to improve tensile strength, elongation, and energy absorption at break of the resin. The blend of DGEBA with 10 wt% of EPN-3 (1:0.8) exhibits maximum improvement in strength, elongation, and energy absorption. EPN loading above 10 wt% is found to lower these properties in a manner similar to the behavior of any filler material. The property profiles of epoxy–EPN blends imply a toughening action by epoxidized novolac resins and the extent of modification is found to depend on the molar ratio between phenol and formaldehyde in the novolac. 相似文献
4.
Jiayao Yang Xingwei He Hengxu Wang Xiaohuan Liu Peng Lin Shengxiang Yang Shenyuan Fu 《应用聚合物科学杂志》2020,137(17):48596
The development of a facile and efficient approach to prepare high-toughness epoxy resin is vital but has remained an enormous challenge. Herein, we have developed a high-performance environment-friendly solid epoxy resin modified with epoxidized hydroxyl-terminated polybutadiene (EHTPB) via one-step melt blending. The characterization, mechanical performance, curing behavior, and thermal properties of EHTPB-modified epoxy resin were investigated. EHTPB-modified epoxy resin exhibited excellent toughness with a 100% increase in elongation at break of tensile than that of neat epoxy resin. The transfer stress and dissipated energy in the rubber phase were predominant mechanisms of toughening. The toughening effect of EHTPB on solid epoxy resin was better than that of some of the previously reported liquid epoxy resins. Meanwhile, at 10 wt % of EHTPB loading, the EHTPB-modified epoxy resin displayed high strength and 22 and 101% improvement of flexural strength and impact strength, respectively. Moreover, at 10 wt % of EHTPB loading, the activation energy of EHTPB-modified epoxy resin for curing reaction decreased from 73.89 to 65.12 kJ·mol−1, which is beneficial for the curing reaction. Furthermore, EHTPB-modified epoxy resin had a good thermal stability and the initial degradation temperature increased from 249 to 313 °C at 10 wt % of EHTPB loading. This work provides a simple-preparation and highly efficient and large-scale approach for the production of high-toughness environment-friendly solid epoxy resins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48596. 相似文献
5.
In this article, epoxidized carbon nanotubes (CNTs) are used to modify current epoxy resins. The produced epoxy groups on the nanotube surface significantly enriched nanotube chemistry and made them soluble in the organic solvents. Atomic force microscopy characterization indicated that epoxidized nanotubes were well dispersed in the organic solvent and most of them were isolated. Fracture surface of modified epoxy resins suggested that fracture toughness of the modified resins was significantly improved, demonstrating fracture characteristic of typical ductile materials. Epoxidized CNTs‐modified epoxy resins demonstrated a 50% increase in the Young's modulus, 32% improvement in the tensile strength with 1 wt % loading. This study provides an effective way to synthesize novel epoxy resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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Takashi Tsujimoto Kohei Takeshita Hiroshi Uyama 《Journal of the American Oil Chemists' Society》2016,93(12):1663-1669
In this study, bio‐based epoxy materials containing functionalized plant oil, such as epoxidized soybean oil (ESO) and epoxidized linseed oil (ELO), were processed with 4‐methylhexahydrophthalic anhydride (MHPA) as a curing agent. In the presence of tetraethylammonium bromide, the curing reaction of epoxidized plant oil and MHPA proceeded at 130 °C to give transparent plant oil‐based epoxy materials. The resulting bio‐based epoxy materials exhibited relatively soft and flexible characters, due to the aliphatic chains of plant oil. The thermal and mechanical properties of the ESO/MHPA polymers depended on the feed molar ratio of anhydride to oxirane. The mechanical properties such as tensile strength and Young's modulus of the ELO/MHPA polymer increased, compared with those of the ESO/MHPA polymer. The glass transition temperature of the ELO/MHPA polymer was higher than that of the ESO/MHPA polymer, because of the high oxirane number of ELO. Furthermore, the ELO/MHPA polymer showed excellent shape memory property. 相似文献
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Plasticized polyvinyl chloride (PVC) films were prepared by melt compounding and compression molding using epoxidized cardanol (EC), a biobased plasticizer and its plasticization effect was compared with epoxidized soybean oil (ESBO) and dioctyl phthalate (DOP). The mechanical, migration, thermal, and barrier properties of the plasticized films were compared. The effect of replacing DOP with EC on the properties of PVC films was also investigated. The tensile strength, elongation at break, tensile modulus and impact strength values of PVC/EC films were higher in comparison to PVC/DOP and PVC/ESBO films at a fixed plasticizer loading of 40 wt.%. Also, the films prepared with a mixture of DOP + EC showed higher tensile strength and elongation at break compared to that of films prepared with only DOP. The PVC/EC films showed good thermal stability and reduced oxygen transmission rate (OTR) compared to PVC/DOP films. The addition of graphene and nanoclay in the PVC/plasticizer system exhibited an increase in oxygen transmission. However, the oxygen barrier property of nano filler incorporated PVC/EC films was better than PVC/DOP films. All the films showed negligible water vapor transmission rate (WVTR). 相似文献
10.
Ye-Shiu Li Ming-Shiu Li Chen-Chi M. Ma Hung-Chung Hsia Der-Shyang Chen 《Polymer International》1994,35(4):371-378
A glycidyl-terminated polyurethane prepolymer was synthesized and used to enhance the properties of epoxy resins. Some properties of glycidyl-terminated PU/epoxy with polyether based (PPG) and polyester based (PBA) glycidyl-terminated PU were investigated in this research. The polyether based glycidyl-terminated PU(PPG) modified epoxy resin proved to be superior to conventional epoxy resins in improved impact strength and fracture energy, but not tensile strength, tensile modulus, flexural strength and flexural modulus. On the other hand, the polyester based glycidyl-terminated PU(PBA) modified epoxy resin had increased mechanical properties while showing slight variation of impact strength and fracture energy. Different mechanisms for this behaviour are advanced in this paper. 相似文献
11.
The aim of this research was to investigate the behaviors of epoxy resin blended with epoxidized natural rubber (ENR). ENRs were prepared via in situ epoxidation method so that the obtained ENRs contained epoxide groups 25, 40, 50, 60, 70, and 80 mol %. The amounts of ENRs in the blends were 2, 5, 7, and 10 parts per hundred of epoxy resin (phr). From the results, it was found that the impact strength of epoxy resin can be improved by blending with ENRs. Tensile strength and Young's modulus were found to be decreased with an increasing amount of epoxide groups in ENR and also with an increasing amount of ENR in the blends. Meanwhile, percent elongation at break slightly increased when ENR content was not over 5 phr. In addition, flexural strength and flexural modulus of the blends were mostly lower than the epoxy resin. Scanning electron microscope micrograph of fracture surface suggested that the toughening of epoxy resin was induced by the presence of ENR globular nodules attached to the epoxy matrix. TGA and DSC analysis revealed that thermal decomposition temperature and glass transition temperature of the samples were slightly different. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 452–459, 2006 相似文献
12.
In this study, the fabrication and characterization of bone ash filled biobased epoxy resin (Super SAP 100/1000, contains 37% biobased carbon content) nanocomposites are presented. Biosource bone ash was modified by size reduction and surface modification processes using a combination of ball milling and sonochemical techniques and characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The modified bone ash particles were incorporated into biobased epoxy with noncontact mixing process. The as-fabricated nanocomposites were characterized using various thermal and mechanical analyses. The nanocomposites showed significant improvement in flexural strength (41.25%) and modulus (34.56%) for 2 wt% filler loading. Dynamic mechanical analysis (DMA) results showed improvement in both storage modulus and loss modulus. Additionally, DMA results showed a slight reduction in glass transition temperature which also complies with differential scanning calorimetry results. Thermomechanical analysis results showed a reduction in the coefficient of thermal expansion. Thermogravimetric analysis results showed improved thermal stability at both onset of degradation and the major degradation. These enhanced thermal and mechanical performances of the epoxy nanocomposites allows them to be suitable for lightweight aerospace, automotive, and biomedical applications. 相似文献
13.
Development and characterization of flax fiber reinforced biocomposite using flaxseed oil‐based bio‐resin 下载免费PDF全文
In this study, acrylated epoxidized flaxseed oil (AEFO) resin is synthesized from flaxseed oil, and flax fiber reinforced AEFO biocomposites is produced via a vacuum‐assisted resin transfer molding technique. Different amounts of flax fiber and styrene are added to the resin to improve its mechanical and physical properties. Both flax fiber and styrene improve the mechanical properties of these biocomposites, but the flexural strength decreases with an increase in styrene content. The mass increase during water absorption testing is less than 1.5% (w/w) for all of the AEFO‐based biocomposites. The density of the AEFO resin is 1.166 g/cm3, which increases to 1.191 g/cm3 when reinforced with 10% (w/w) flax fiber. The flax fiber reinforced AEFO‐based biocomposites have a maximum tensile strength of 31.4 ± 1.2 MPa and Young's modulus of 520 ± 31 MPa. These biocomposites also have a maximum flexural strength of 64.5 ± 2.3 MPa and a flexural modulus of 2.98 ± 0.12 GPa. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41807. 相似文献
14.
Both epoxidized linseed oil and transesterified epoxidized linseed oil were acrylated to form UV curable bio-based oligomers. The synthesis was confirmed by FTIR and 1H NMR and oxirane oxygen content (OOC). The OOC value of epoxidized linseed oil was determined to be 8.2 % which was reduced to 8.0 % after transesterification confirming the retaining of epoxy groups. The lower OOC of acrylated epoxidized linseed oil (AELO) (2.1 %) and acrylated epoxy methyl esters (AEME) (0.9 %) revealed successful acrylation. The degree of acrylation in AEME was higher (~ 90 %) than AELO (~ 77%) and most importantly, the viscosity of AEME was much lower than AELO revealing better processability for industrial use. 相似文献
15.
增塑剂对硅橡胶硫化胶性能的影响 总被引:1,自引:0,他引:1
在确定硅橡胶基本配方的前提下,分析了增塑荆对硅橡胶硫化胶性能的影响。研究结果表明,试验中选用的酯类增塑剂和醇类增塑荆均能明显降低硅橡胶硫化胶的模量,但采用自制的环氧改性胶粘荆进行硅橡胶硫化胶与金属粘接时,含酯类增塑荆的硫化胶粘接效果较好。试样破坏形式为橡胶内聚破坏;而采用醇类增塑剂的硫化胶。粘接质量较差。试样破坏形式均为粘接面破坏。 相似文献
16.
Baolong Zhang Shaowen Liao Keyu Shi Zongjie Du Manquan Du Lu Zheng Jifu Huang 《应用聚合物科学杂志》1999,73(9):1787-1792
A series of acrylic copolymer modifiers with mesogenic side chain (LCGMB) were synthesized and used to modify E-51/DDM system. The dynamic mechanical behavior and impact strength of the modified systems were investigated. The results showed that the impact strength and modulus were influenced by the composition and the amounts of the modifiers. With addition of 10% (wt %) LCGMB (molar ratio of GMA : HEMA : MMA : BA = 4 : 10 : 26 : 60) based on the amount of the epoxy resin, the modified systems obtained 100% increase in impact strength, 10% increase in modulus, and a little increase in Tg. The toughening mechanism of the modified systems was also discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1787–1792, 1999 相似文献
17.
Incorporation of epoxidized soybean oil as co‐matrix in epoxy resin toward developing plastisol/particulate toughened glass fiber composites 下载免费PDF全文
Madoor Comandore Rangasai Subhash Hanmant Bhosale Vismay Vinodkumar Singh Subrata Bandhu Ghosh 《应用聚合物科学杂志》2014,131(15)
Epoxidized soybean oil was incorporated as a co‐matrix into an epoxy resin, and the hybrid resin system was used for preparing glass fiber‐reinforced composites. Effect of addition of poly(vinyl chloride) plastisol and selected particulate fillers (fly ash and wood flour) to epoxy/epoxidized soybean oil matrix on mechanical and water uptake properties of glass fiber‐reinforced composites were studied. Fourier transform infrared spectroscopy was used to reveal the curing state of these composites. It was observed that tensile strengths and moduli decreased with the inclusion of all additives. However, addition of poly(vinyl chloride) plastisol, fly ash, and wood flour particulate fillers showed significant increase in impact strengths compared with neat epoxy composite in a synergistic manner. Water uptake results of the composites were found to be in good agreement with ? OH peak intensities obtained from Fourier transform infrared spectroscopy. Finally, acousto‐ultrasonic nondestructive technique was successfully used to assess damage states and to relate stress wave factors with tensile strength properties of modified epoxy‐based glass fiber composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40586. 相似文献
18.
An epoxidized vegetable oil of Mesua ferrea L. seed was prepared and used as a reactive diluent for commercial BPA-based epoxy resin at different compositions for the first time. The prepared epoxidized oil (ENO100) was characterized by determination of physical properties like epoxy equivalent, viscosity, hydroxyl value, saponification value, iodine value, acid value, etc. and FTIR study. The morphology and rheological characteristics of the ENO100 modified commercial epoxy systems have been studied by SEM and rheometer. The performance of poly(amido amine) cured above resin systems have been investigated by the measurement of drying time, tensile strength, elongation at break, adhesive strength, impact resistance, scratch hardness, gloss and chemical resistance studies. The results indicate that the epoxidized oil not only reduces the viscosity of the BPA-based epoxy resin but it also enhances the performance of the cured resin. The performance of this system (50 wt.% dilution) was further enhanced by formation of nanocomposites using ex-situ technique with organically modified nanoclay at different dose levels (1–5 wt.%).The formation of nanocomposites was confirmed by XRD, SEM and FTIR studies. The studies of above performance indicate the enhancement of properties compared to pristine system. As naturally renewable diluent is used in the above studies, so the resultant nanocomposites are green high performance materials with zero VOC. 相似文献
19.
Mengye Cao Hualin Wang Ruizhi Cai Qing Ge Suwei Jiang Linfeng Zhai Shaotong Jiang 《应用聚合物科学杂志》2015,132(45)
This work aimed to develop a novel epoxy‐modified tung oil waterborne insulation varnish with blocked hexamethylene diisocyanate as a curing agent. The Diels–Alder reaction between tung oil and maleic anhydride, and the ring‐opening esterification reaction of epoxy resin were confirmed. The conversion rate of epoxy was explored as a function of reaction time and temperature. The effects of epoxy resin content on the thermal stability, water absorption and insulation properties (insulation strength, volume resistivity, and surface resistivity) of films were investigated, and the resistances of films to salted water were evaluated. The increase in epoxy resin contents could improve the thermal stability and insulation properties of films, and decreased the water adsorption of films, but when the epoxy resin content reached 30% and above, the water solubility of resin became poor. After being immersed in 3.5 wt % NaCl solution, the electrical insulation strength of films were lower than that in dry state, and decreased as the immersed time prolonged. In particular, the electrical insulation strength loss of films increased significantly for epoxy resin content at 15% and below. Furthermore, the increase of epoxy resin content could improve the hardness and adhesion of films, but the flexibility of films became worse. On the basis of experimental, the epoxy resin content at 25% was appropriate to prepare waterborne epoxy‐modified tung oil resin. The resulting varnish may have potential as an immersing insulation varnish for the spindle of electric motor. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42755. 相似文献
20.
The new biobased nanocomposites are processed from anhydride-cured epoxidized linseed oil (ELO)/ or octyl epoxide linseedate (OEL)/diglycidyl ether of bisphenol F (DGEBF) epoxy matrix and organomontmorillonite clay. The selection of anhydride curing agent and biobased epoxy resulted in an excellent combination to provide an epoxy matrix having high elastic modulus, high glass transition temperature, and high heat distortion temperature (HDT), with higher amounts of functionalized vegetable oil (FVO), compared with amine-cured biobased epoxy. The sonication technique was utilized to process the organically-modified clay nanoplatelets in the glassy biobased epoxy network resulting in nanocomposites where the clay nanoplatelets are almost completely exfoliated and homogeneously dispersed in the epoxy network. The processed exfoliated clay nanocomposites showed higher storage modulus compared with the neat epoxy containing the same amount of FVO. Therefore, the lost storage modulus with larger amount of FVO can be regained with exfoliated clay nanoreinforcement. 相似文献