Preparation of Impact Resistance Epoxy Resin Encapsulating Materials

2013 ◽  
Vol 327 ◽  
pp. 18-22
Author(s):  
Kai Zhang ◽  
Jing Hui Fan ◽  
Yan Ma

According to research requests of encapsulating materials used in anti-impact precision electron apparatus parts, the materials system was designed on the relation of mechanics performance and techniques properties. Then epoxy resin E-51 was toughening modified with a kind of self-synthesized polyester epoxy resin which had liquid crystal groups. The results showed that the optimized epoxy resin encapsulating materials has high compression strength and favorable operating properties. The impact strength of prepared epoxy resin encapsulating materials increased 4.0 times, and the gel time at room temperature was over 100 minutes.

2011 ◽  
Vol 52-54 ◽  
pp. 2056-2059
Author(s):  
Da Hu Yao ◽  
Yu Qing Zhang ◽  
Joong Hee Lee

A bisphenol-A glycidol ether epoxy resin was toughened in cryogenic temperature using reactive macroglycol as modifiers. The properties of modified epoxy resin were characterized by SEM and DMA. Phase-separated structure formed during curing process in the PPG and PTMG modified epoxy resins system, and did not occurred in the PEO modified epoxy resins system. The impact strength of epoxy resin increased at both room temperature (RT) and cryogenic temperature (CT, 77 K) using PEO as modifier. The DMA results confirm that the introduction of PEO chains in the structure of the epoxy increases the mobility of the molecular segment of epoxy network at both RT and CT.


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.


2015 ◽  
Vol 24 (4) ◽  
pp. 096369351502400
Author(s):  
C. K. Tai ◽  
R. Ahmad ◽  
H. M. Akil ◽  
M. M. Ratnam

The combined effects of alkali treatment and compression molding temperature on the flexural strength and impact resistance of woven coir fibre composites are investigated. Ten pieces of composites plates made from single-layer woven coir fibre fabricated under different process parameters were used in the study. Five pieces of the coir woven fibre were treated with 6% sodium hydroxide (NaOH) solution while another five were left untreated. The compression molding temperature were varied between room temperature (25°C), 50°C, 75°C, 100°C and 125°C. The flexural properties of the composite were evaluated using the three-point flexural test, while the impact resistance was investigated by drop weight impact tests using a specially designed indenter. The indentation radius on each test specimen was measured using a 3-D metrology system and the depth of indentation was determined from the geometry of the indenter. The results show that the maximum flexural load to failure is improved by 38.9% when the fibres were treated and the compression molding temperature is increased to 125°C. The flexural modulus generally decreased with increase in the molding temperature. The depth of indentation in the treated coir woven composites is lower than that of untreated fibre composite at all molding temperatures. The impact resistance of both untreated and treated fibre composites decreased with the increase in the compression molding temperature. Composites fabricated by molding at room temperature, 50°C and 75°C using treated fibre produced the best impact properties.


2014 ◽  
Vol 936 ◽  
pp. 3-7
Author(s):  
Shi Hui Chen ◽  
Jun Gang Gao ◽  
Hong Zhe Han ◽  
Chao Wang

In order to modify the properties of the epoxy composites, an alkali catalyzed biphenyldiol formaldehyde resin (BPFR) was synthesized and used to cure epoxy resin (ER). γ-Glycidoxypropyl trimethoxysilane (KH-560) was used as a reinforcer of the composites. Laminates of the BPFR/ER fiberglass reinforced composites with different (KH-560) contents were prepared. The influence of the KH-560 content on the glass transition temperature (Tg) and thermal degradation properties of the composites was researched by dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TG). The mechanical, electrical properties of the composites were determined. The results showed that the interfacial bonding strength between resin matrix and fiberglass can be efficiently improved with the presence of KH-560. When the ratio of BPFR and ER is 3 : 7, the content of KH-560 is 5 ~7 wt%, the impact resistance of the fiberglass reinforced composites is 61.35~78.59 kJ/m2, the tensile resistance is 150.37~162.54 MPa, which are all 30 % higher than that of no added; The dielectric constant ε and dielectric loss tanδ of the composites is between 0.50~0.68 and between 0.008~0.01, respectively.


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.


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.


2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.


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.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Retno Eka Pramitasari ◽  
Mochamad Arif Irfa'i ◽  
Reza Prasetyo

The development of increasingly advanced technology, especially in the health sector, can lead to an increase in the need for composite materials used. This study aims to describe the results of the concentration of KOH solution and the orientation of the ramie fiber on the impact strength of composites with a polyester matrix. This research is an experimental study with the manipulation variables are the concentration of the KOH solution and the orientation of the fiber direction by determining the value of the impact strength as the dependent variable of ramie fiber as a control variable of this study. This study obtained the optimum impact test result of 0.0711 J/mm2 with 5% KOH solution concentration and located at 0o/45o/90o fiber direction orientation. While the results of the lowest impact test resulted in a value of 0.0101 J/mm2 without soaking the KOH solution and located at 90o/0o/90o fiber direction orientation.


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