Modification of Epoxy Resin by Reactive Block Copolymer SEBSMB

2014 ◽  
Vol 496-500 ◽  
pp. 71-74 ◽  
Author(s):  
Jian Ping Zhou ◽  
Hui Ru Wu ◽  
Wan Li Fu ◽  
Shi Jun Jia

Reactive block copolymer SEBSMB was used as modifier to toughen epoxy resin. The results indicate that ideal enhancement of toughness could be achieved by this method. The impact strength increases with increase of the content of SEBSMB in the matrix and it could be enhanced by 200% at 20wt% addition of the modifier. DMA and TG results show that the modified resin exhibits similar thermal stability as compared with pure epoxy resin. The toughening effect may be ascribed to the unique self-assembling structure of SEBSMB in the matrix and a hypothetical model was proposed.

2010 ◽  
Vol 123-125 ◽  
pp. 1139-1142 ◽  
Author(s):  
Sawitri Srisuwan ◽  
Pranee Chumsamrong

In this study, the effects of weave type and fiber content on the physical properties of woven sisal fiber/epoxy composites were investigated. Sisal fibers used in this work were obtained from Nakhon Ratchasima, Thailand. Both untreated and alkali-treated fibers were employed. The woven sisal fibers were manufactured by hand weaving process. The fiber content in sisal fiber/epoxy composites were 3 wt.%, 5 wt.% and 10 wt.%. The composites were cured at room temperatures. In order to determine mechanical properties of the composites, flexural and impact tests were applied. Flexural strength and flexural modulus of all composites were higher than those of pure epoxy resin and tended to increase with increasing fiber content. The impact strength of all composites was lower than that of pure epoxy resin. The composites containing 10 wt.% sisal fibers showed the highest impact strength. There was no definite influence of weave type on flexural properties of the composites. At 3 and 5 wt.% fiber, the composites containing plain weave fibers seemed to show a higher impact strength than the composites containing other weave types.


2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.


2016 ◽  
Vol 51 (9) ◽  
pp. 1197-1208 ◽  
Author(s):  
Wei Li ◽  
Hongyu Li ◽  
Xinguo Yang ◽  
Wei Feng ◽  
Hongyun Huang

This paper reported a facile one-pot strategy for fabrication of sulfonic graphene oxide–epoxy resin nanocomposites. The rheological and thermal properties were employed to characterize the viscosity and the curing temperature of epoxy resin. Fourier transform infrared spectra for sulfonic graphene oxide and nanocomposites indicated that the sulfonic graphene oxide contains chemical cross-linking responsible for better interactions with the epoxy resin. The state of dispersion was evaluated at different scales by still picture camera and scanning electron microscopy (SEM). Tensile property tests indicated that the tensile strength and elasticity modulus of sulfonic graphene oxide–epoxy resin nanocomposites decreased slowly with increasing of sulfonic graphene oxide content. The critical flexural property and impact strength of epoxy resin filled with sulfonic graphene oxide nanocomposites were measured. The content, size, and dispersion state of sulfonic graphene oxide were examined. It was found that the content of sulfonic graphene oxide has greater impact on both flexural property and impact strength of nanocomposites compared with other conditions. For instance, the impact strength increased by 113.0% and the flexural strength and modulus increased by 39.3% and 55.7% using 1 wt.% sulfonic graphene oxide as compared to neat epoxy resin.


2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.


2015 ◽  
Vol 744-746 ◽  
pp. 1463-1466
Author(s):  
Xi Wang

This paper presents the synthesis of a new type of flexible epoxy curing agent and an approach to improve the toughness of epoxy resin by curing without reducing the strength and modulus of the resin-cured material. The results show that the degree of toughness reaches maximum values when the flexible curing agent is applied at weight percentages (wt.%) between 10% and 15%. When the amount of flexible curing agent added to epoxy resin weight is 10wt.%, the impact toughness and fracture toughness increases by 33.3% and 96.3%, respectively, compared with the pure epoxy resin. When the amount of flexible curing agent added to epoxy is 10wt.%, the resulting impact thoughness of the material is 19.5 kJ•m-2 at-50°C, the impact toughness of pure epoxy resin is only 7.96 kJ•m-2.


2014 ◽  
Vol 926-930 ◽  
pp. 198-201
Author(s):  
Li Ying Guo ◽  
Jin Lin Liu ◽  
Peng Cheng Huang ◽  
Jun Hai He ◽  
Shi Yang Bai ◽  
...  

Polyether imidazole ionic liquid (PIIL) was blended with general-purpose epoxy resin (EP). PIIL/EP was cured by ethylenediamine curing agent. The structure of PIIL/EP was determined by FTIR. The effect of the content of PIIL on the impact strength of EP was studied. The toughness of epoxy resin could be significantly improved by PIIL. The impact strength of the modified EP was improved with the increase of PIIL and leveled off when the content of PIIL was more than 45%, and the modified EP showed rubber elasticity obviously.


2010 ◽  
Vol 150-151 ◽  
pp. 698-702
Author(s):  
Zhi You Yang ◽  
Shao Rong Lu ◽  
Zhi Yi Huang ◽  
Chun He Yu ◽  
Kuo Liu

A new kind of lower-branched liquid crystalline polyester (LLCP) containing polyester mesogenic units was synthesized by p-hydroxybenzoic acid, terephthalyl chloride and trimellitic anhydride (TMA), then was used as collaborative modifier for the epoxy resin (E-51) with γ-azyl polyhedral oligomeric silsesquioxane (POSS). The experimental results showed that the LLCP / POSS could act as an effective toughening modifier for the epoxy resin. The impact strength of the composites modified with LLCP and POSS was 1.1 times higher than that of the unmodified system. The temperature of starting decomposition and maximum decomposition rate improved about 20 oC and 13 oC , respectively.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Nina Graupner ◽  
Jörg Müssig

The present study focuses on a comparison between different cellulose fiber-reinforced thermoplastics. Composites were produced with 30 mass-% lyocell fibers and a PLA or PP matrix with either an injection (IM) or compression molding (CM) process. Significant reinforcement effects were achieved for tensile strength, Young’s modulus, and Shore D hardness by using lyocell as reinforcing fiber. These values are significantly higher for PLA and its composites compared to PP and PP-based composites. Investigations of the fiber/matrix adhesion show a better bonding for lyocell in PLA compared to PP, resulting in a more effective load transfer from the matrix to the fiber. However, PLA is brittle while PP shows a ductile stress-strain behavior. The impact strength of PLA was drastically improved by adding lyocell while the impact strength of PP decreased. CM and IM composites do not show significant differences in fiber orientation. Despite a better compaction of IM composites, higher tensile strength values were achieved for CM samples due to a higher fiber length.


2020 ◽  
Vol 15 (1) ◽  
pp. 113-128
Author(s):  
Chouaib Aribi ◽  
Aissa Bouaissi ◽  
Brahim Safi ◽  
Mohammed Saidi

Abstract This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.


2021 ◽  
Author(s):  
Chenglin Zhang ◽  
Guohua Gu ◽  
Shuhua Dong ◽  
Zhitao Lin ◽  
Chuncheng Wei ◽  
...  

Abstract In this study, the nonisothermal differential scanning calorimetry (DSC) was carried out to evaluate the curing reaction of fiber/epoxy laminates. The optimal curing process of the prepreg was obtained by T-β extrapolation method and nth-order reaction curing kinetic equation. The bending strength, impact strength and thermodynamic properties of the composite laminates with different ply orientations were investigated, respectively. The results show that the apparent activation energy and the reaction order of the prepregs are 82.89 kJ/mol and 0.92, respectively. The curing process of carbon fiber/epoxy resin prepreg is 130 ℃ /60min + 160 ℃/30 min. The bending strength of [0]10 laminate is 1948.3 MPa, which is 11.8 times higher than that of [+ 45/-45]5s laminate, and 96.4% higher than that of [0/90]5s laminate. The impact strength of [0]10 laminate is higher than that of [+ 45/-45]5s and [0/90]5s laminates. The glass transition temperature (Tg) of the laminates is 142 ~ 146 ℃, and the loss factor of [0]10 laminate is significantly higher than that of [+ 45/-45]5s and [0/90]5s laminates. This research provides a theoretical basis for the further application of prepregs to fiber composite materials.


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