scholarly journals Reduced density spheroplastic based on hollow phenol-formaldehyde microspheres and epoxy resin

2019 ◽  
Vol 58 (4) ◽  
pp. 98-101
Author(s):  
Vladimir Yu. Chukhlanov ◽  
◽  
Kirill V. Smirnov ◽  
Natalia V. Chukhlanova ◽  
◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Phenol Formaldehyde ◽  
Charpy Impact ◽  
Epoxy Oligomer ◽  
Hollow Microspheres ◽  
Stationary Mode ◽  
Gel Formation ◽  
The Impact

In this article the physical-mechanical, thermal and electrical properties of spheroplastic based on epoxy resin ED-20 and hollow phenol-formaldehyde microspheres were studied. The samples were obtained by mixing an epoxy resin, cured with polyethylene polyamine, with hollow phenol-formaldehyde microspheres, poured into a mold and then cured at room temperature. The influence of the filler on the kinetics of the interaction of epoxy oligomer and aliphatic polyamine was studied. The effect of reducing the time of gel formation may occur due to the possible presence of reactive groups on the surface of microspheres. The experiments showed that the introduction of hollow phenol-formaldehyde microspheres in General leads to a slight decrease in the gel formation time. It is established that the introduction of hollow microspheres into the composition leads to a decrease in the density of the finished composition. The impact strength of spheroplastic was determined in accordance with GOST 4647-2015 "Method of Charpy impact strength determination" (ISO 179-1: 2010, NEQ). The introduction of hollow microspheres into the composition leads to a change in the impact strength of the composition in the direction of its decrease. A similar trend is observed in the study of the strength in the separation from the substrate of different materials. The coefficient of thermal conductivity was determined in a stationary mode on the device ITP-MG4"100" GOST 7076-99 "Method for determining the thermal conductivity and thermal resistance in a stationary thermal regime." Studies have shown that an increase in the content of hollow microspheres in the composition to 15% leads to a gradual decrease in the thermal conductivity coefficient to 0.74 W/m∙K. The studied materials can be used as thermal insulation materials and for the manufacture of products used in various fields of science and technology.

scholarly journals Effect of sulfuric acid solution on thermal conductivity and impact strength of epoxy resin reinforced by silicon dioxide powder

2019 ◽  
Vol 17 (41) ◽  
pp. 82-90
Author(s):  
Baraa Khalil Ibrahim
Keyword(s):  
Thermal Conductivity ◽  
Sulfuric Acid ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Weight Ratio ◽  
Chemical Solution ◽  
Dioxide Powder ◽  
Before And After ◽  
Percentage Weight ◽  
The Impact

In this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared by hand Lay-up method, to measure the change in the thermal conductivity and Impact Strength of epoxy resin before and after immersion in H2SO4 Solution with a 0.3N for 10 days. The results before immersion decreases with the increase of the weight ratios of the reinforcement material (SiO2), It changed from (82.6×10-2 to 38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) % respectively, but after immersion time in the chemical solution where it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became (46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of the Impact strength decreased by increasing the percentage weight ratio, it changed from (1.48 to 0.87 kJ/m2) with change weight ratios from (3 to 12) % respectively, but found an increase in the value of Impact Strength after immersion in the chemical solution Where it was (1.28 kJ/m2) at the weight ratio of 6 % and became (1.82 kJ/m2) at the same weight ratio after immersion in sulfuric acid at normality of 0.3 for 10 days.

scholarly journals Synergetic Effects of Silver Nanowires and Graphene Oxide on Thermal Conductivity of Epoxy Composites

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1264 ◽  
Author(s):  
Li Zhang ◽  
Wenfeng Zhu ◽  
Ying Huang ◽  
Shuhua Qi
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Silver Nanowires ◽  
Phonon Transport ◽  
Epoxy Composites ◽  
Hybrid Fillers ◽  
Interfacial Contact ◽  
The Impact

One-dimensional silver nanowires (AgNWs) and two-dimensional graphene oxide (GO) were combined to construct a three-dimensional network structure. The AgNWs can effectively inhibit stacking of adjacent GO sheets by occupying regions between layers of GO. Moreover, the GO sheets embedded in the gaps of the AgNWs network increase the interfacial contact area between the AgNWs and the epoxy matrix, resulting in the formation of more efficient phonon transport channels. To prepare an epoxy-based thermal conductive composite, hybrid networks were fabricated and added to epoxy resin using a solution mixing method. Significant synergistic effects were observed between the AgNWs and GO sheets. The thermal conductivity of epoxy composites filled with 10 wt.% AgNW/GO hybrids was found to be 1.2 W/mK and the impact strength was 28.85 KJ/m2, which are higher than the corresponding values of composites containing AgNWs or GO sheets alone. Thus, the thermal conductivity and impact strength of the epoxy composites were improved. The additive effects are mainly owing to the improved interfacial contact between the hybrid fillers and the epoxy resin, resulting in a more efficient phonon transport network. The use of hybrid fillers with different structures is a simple and scalable strategy for manufacturing high-performance thermally conductive materials for electronic packaging.

Preparation and properties of novel sulfonic graphene oxide–epoxy resin nanocomposites by resin transfer molding process

2016 ◽  
Vol 51 (9) ◽  
pp. 1197-1208 ◽  
Author(s):  
Wei Li ◽  
Hongyu Li ◽  
Xinguo Yang ◽  
Wei Feng ◽  
Hongyun Huang
Keyword(s):  
Graphene Oxide ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Curing Temperature ◽  
Flexural Property ◽  
Oxide Content ◽  
Molding Process ◽  
One Pot ◽  
Epoxy Resin Nanocomposites ◽  
The Impact

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.

The Effect of Chitosan Addition in Acrylic Resin Matrix towards the Residual Monomers and Impact Strength

2021 ◽  
pp. 2280-2285
Author(s):  
Titik Ismiyati ◽  
Ananto Ali Alhasyimi
Keyword(s):  
Acrylic Acid ◽  
Impact Strength ◽  
Charpy Impact ◽  
Acrylic Resin ◽  
Test Sample ◽  
Acid Group ◽  
Resin Matrix ◽  
Residual Monomer ◽  
Group 2 ◽  
The Impact

Background: A residual monomer might have impact on the quality of acrylic resin since its caused allergic reactions and inflammation. Chitosan is a biocompatible material and potential to reduce residual monomers and ameliorate the impact strength of acrylic resin Objective of the study: To examine the effect of an acrylic resin matrix mixed with chitosan together with 1% and 2% acrylic acid as denture base and orthodontic material on residual monomers and impact strength. Methodology: There were 30 samples for the test analysis. The impact strength test sample formed with a plate size of 55 × 10 × 10mm, whereas the residual monomer test sample was prepared into powder. The test samples were divided into 3 groups, of 10 samples. Group 1 acrylic resin only, group 2 acrylic resin matrix mixed with chitosan and 1% acrylic acid, group 3 is the same as group 2 but with a concentration of 2% acrylic acid. Gas chromatography was used for measuring the residual monomers. The impact strength was tested by the Charpy impact. The data was evaluated using the ANOVA and correlation test. Results: There were significant differences (p < 0.05) in acrylic resin without addition with the matrix of acrylic resin with chitosan and acrylic acid 1% and 2% to the number of monomers and impact strength. Conclusion: The mixture of acrylic resin with chitosan and acrylic acid 1% and 2% can reduce the amount of residual monomer and increase the impact strength.

scholarly journals The Effect of Crystallinity on the Toughness of Cast Polyamide 6 Rods with Different Diameters

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 293
Author(s):  
Miklós Odrobina ◽  
Tamás Deák ◽  
László Székely ◽  
Tamás Mankovits ◽  
Róbert Zsolt Keresztes ◽  
...  
Keyword(s):  
Impact Strength ◽  
Impact Test ◽  
Charpy Impact ◽  
Polyamide 6 ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Tensile Impact ◽  
Different Diameters ◽  
The Impact ◽  
The Degree Of Crystallinity

The present paper concentrates on the toughness and the degree of crystallinity of the magnesium-catalyzed polyamide 6 rods cast in different diametres, which are commonly used for gear manufacturing. Its toughness cannot be regarded as a constant feature due to the casting technology. The mechanical properties of the semi-finished products are sensitive to the manufactured dimension, e.g., cast diameter, which are investigated by the Charpy impact test and tensile impact test. It is generally accepted that the impact strength and tensile-impact strength correlate with the degree of crystallinity beside many other material’s feature. Crystallinity is evaluated by Differential Scanning Calorimetry. The aim of this study is to determine the relationship between toughness and crystallinity of the magnesium-catalyzed cast PA6 rods with different diameters. For the research cast rods between 40 and 300 mm diameter were selected in seven-dimensional steps. Based on the results, it was found that the toughness depends strongly on the diameter size. Furthermore, it is proved that the crystallinity explains 62.3% of the variation of the Charpy’s impact strengths, while the tensile impact method was not suitable to detect the difference between the test samples.

scholarly journals Preparation and properties of flame-retardant epoxy resins containing reactive phosphorus flame retardant

2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  
Keyword(s):  
Impact Strength ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Epoxy Resins ◽  
Phosphorus Content ◽  
Phosphorus Compound ◽  
Phosphorus Compounds ◽  
Limiting Oxygen Index ◽  
The Impact

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.

scholarly journals Cyanate ester resin based composites with high toughness and thermal conductivity

RSC Advances ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 5722-5730 ◽  
Author(s):  
Le Zhai ◽  
Zhenxin Liu ◽  
Chen Li ◽  
Xiongwei Qu ◽  
Qingxin Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Impact Strength ◽  
Cyanate Ester ◽  
Core Shell ◽  
Microelectronic Packaging ◽  
Cyanate Ester Resin ◽  
High Toughness ◽  
The Impact

h-BN particles were used to fabricate cyanate ester/core–shell structured polyacrylic/BN composites. The impact strength and the thermal conductivity of the composites were simultaneously increased, which may be used in microelectronic packaging.

Research of Epoxy Resin Modified by Polyether Imidazole Ionic Liquid

2014 ◽  
Vol 926-930 ◽  
pp. 198-201
Author(s):  
Li Ying Guo ◽  
Jin Lin Liu ◽  
Peng Cheng Huang ◽  
Jun Hai He ◽  
Shi Yang Bai ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Impact Strength ◽  
Epoxy Resin ◽  
General Purpose ◽  
Rubber Elasticity ◽  
Curing Agent ◽  
The Impact

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.

Lower Branched Liquid Crystalline Polyester POSS Used as Collaborative Modifier for Epoxy Resin

2010 ◽  
Vol 150-151 ◽  
pp. 698-702
Author(s):  
Zhi You Yang ◽  
Shao Rong Lu ◽  
Zhi Yi Huang ◽  
Chun He Yu ◽  
Kuo Liu
Keyword(s):  
Impact Strength ◽  
Epoxy Resin ◽  
Decomposition Rate ◽  
Liquid Crystalline ◽  
Hydroxybenzoic Acid ◽  
Trimellitic Anhydride ◽  
Maximum Decomposition Rate ◽  
Oligomeric Silsesquioxane ◽  
The Impact ◽  
Liquid Crystalline Polyester

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.

scholarly journals Charphy Impact of Medium Molecular Weight Phenol Formaldehyde (MMwPF) Plywood

2020 ◽  
Vol 18 (1) ◽  
pp. 24-30
Author(s):  
Norhayati Ibrahim ◽  
Hasmawi Khalid
Keyword(s):  
Molecular Weight ◽  
Oil Palm ◽  
Phenol Formaldehyde ◽  
High Surface ◽  
Charpy Impact ◽  
High Water ◽  
Tissue Cell ◽  
Uniform Density ◽  
Tropical Hardwood ◽  
The Impact

Plywood is a wood product frequently utilized in building as part of concrete formwork systems. In the concreting process, plywood formwork needs to be strongly made to withstand the pressure subjected by the wet concrete as well as the impact. To reduce the dependency on solid timber as plywood, oil palm stem offers alternative materials. There are four main weaknesses of oil palm stem (OPS) as a material for plywood manufacturing; high variations in density and moisture content (MC), high water absorption and high surface roughness. Therefore, this study modified the drying and treatment process of OPS veneer. The veneer was predried by using roller presser for removing a large amount of water and later treated with medium molecular weight phenolformaldehyde (MMwPF) to bond together parenchyma tissue, cell wall, and a lumen for much uniform density and better surface bonding. The Charpy impact of OPS plywood developed in this study denoted as PTA was investigated. These properties were compared with the properties of another two types of commercial OPS plywood denoted as PTB and PTC which were manufactured using OPS veneer with tropical hardwood veneer for face and back veneer and control plywood denoted as PTD which was manufactured using 100% tropical hardwood veneer. The results showed that PTA has the highest mean value of energy and strength for both notched and unnotched Charpy impact.

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