scholarly journals The Effect of UV Exposure on the Service-life of Thermochromic Microcapsules Integrated into the Epoxy Matrix

2021 ◽  
Author(s):  
Olga BULDERBERGA ◽  
Andrey ANISKEVICH
Keyword(s):  
Mechanical Properties ◽  
Service Life ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Uv Light ◽  
Colour Change ◽  
Critical Time ◽  
Tensile Tests ◽  
Uv Exposure ◽  
Exposure Effect

The effect of ultraviolet (UV) exposure on the service-life of thermochromic microcapsules integrated into the epoxy matrix was investigated. The microcapsules of the formaldehyde shell contain the core of thermochromic leuco dye. Seven sets of epoxy resin samples filled with concentrations from 0 to 10 wt.% of microcapsules were investigated. The composite samples were exposed to UV for approximately 1000 h. For the quantitative evaluation of colour change under UV, a fast and simple original procedure based on samples’ image treatment was developed. With the exposure time intervals of 50 h, samples were taken out from the UV light chamber to evaluate the exposure effect on their reversible thermochromic ability and mechanical properties. Periodical evaluation of the UV light effect on mechanical properties during the exposure was performed by microhardness tests. Tensile tests of the samples till the fracture were performed every 200 h. The critical time under the exposure of the UV lamp that destroys the reversible thermochromic reaction of the microcapsules was defined as 200 h. At the same time, it has been found that the mechanical properties of the epoxy resin under the same UV source were not strongly affected after 1000 h of irradiance and changed in the frame of ~ 10 %.

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

scholarly journals Effects of Ultraviolet Radiation on Recycled and Virgin HDPE Corrugated Pipes Used in Road Drainage Systems

2021 ◽  
Author(s):  
Khanh Q. Nguyen ◽  
Patrice Cousin ◽  
Khaled Mohamed ◽  
Mathieu Robert ◽  
Adel El-Safty ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Uv Light ◽  
Morphological Structure ◽  
Tensile Tests ◽  
Repair Process ◽  
Thermomechanical Properties ◽  
Uv Exposure ◽  
Scanning Calorimetry ◽  
Drainage Systems ◽  
Significant Difference

Abstract High-density polyethylene (HDPE) pipe is one of the materials of interest for use in road drainage systems. The combination of ultraviolet (UV) light, temperature, and moisture can produce weak spots and lead to pipe degradation during the storage, installation, and repair process. The objective of this study was to evaluate changes in the chemical, morphological structure, and thermomechanical properties of recycled and virgin pipes under UV exposure. Laboratory accelerated aging tests were conducted by exposing pipes to UV for 3600 hours with an irradiance of 0.89 W/(m2 nm) at a wavelength of 340 nm. A cycle of 12 hours—comprised of 8 hours of UV radiation at 60°C and 4 hours of no UV radiation at 50°C corresponding to no water condensation—was performed to condition the specimens. HDPE specimens were taken out after 3600 hours and analyzed with FTIR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscopy), DSC (differential scanning calorimetry), oxidative-induction time (OIT) measurements, and tensile tests. The results show that the recycled pipes maintained good properties and were not significantly affected by UV radiation, similarly to the virgin pipes. Statistical analysis using one-way analysis of variance (ANOVA) shows that there was no significant difference between tensile strength, elastic modulus, and hardness measurements before and after UV exposure. There were only a few small changes in the surface of the pipes. The addition of carbon black, antioxidants, and UV stabilizers prevented further aging of the pipes during UV exposure.

Preparation and Mechanical Properties of Epoxy Resin Reinforced with Jeffamines-Grafted Carbon Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 553-556 ◽  
Author(s):  
Ling Fei Shi ◽  
Gang Li ◽  
Gang Sui ◽  
Xiao Ping Yang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Epoxy Resin ◽  
Photoelectron Spectroscopy ◽  
Epoxy Matrix ◽  
Resin Matrix ◽  
Mechanical And Thermal Properties ◽  
Time Dynamic ◽  
Multi Walled Carbon Nanotubes ◽  
The Impact

The increasing proliferation and application of advanced polymer composites requires higher and broader performance resin matrices. Poly(oxypropylene) with –NH2 end-groups has been widely used to toughen epoxy resins, but the strength of resin matrix may be reduced due to the addition of flexible segments in the crosslinking network. Carbon nanotubes (CNTs) have been paid more and more attention in recent years because of their superior thermal and mechanical properties. In this paper, CNTs grafted with Jeffamines T403 were used to simultaneously improve the reinforcement and toughening of an epoxy resin. The untreated multi-walled carbon nanotubes (u-MWNTs) were functionalized with amine groups according to three steps: carboxylation, acylation, and amidation. The f-MWNTs were characterized by Fourier transform infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS). The experimental results indicated that the T403 was grafted to the surface of MWCNTs. The mechanical and thermal properties of epoxy with f-MWNTs were investigated. The tensile and flexural strength increased by 7.77 % and 7.03 % after adding 0.5wt% f-MWCNTs without sacrificing the impact toughness. At the same time, dynamic mechanical thermal analysis (DMTA) showed that the glass transition temperature (Tg) of epoxy with f-MWNTs were increased. The fracture surface of epoxy with f-MWNTs was observed by scanning electron microscopy (SEM) to understand the dispersion of f-MWNTs in epoxy matrix and interfacial adhesion between f-MWNTs and epoxy matrix, which can be attributed to the strong interfacial bonding between f-MWNTs and epoxy resin.

scholarly journals A Study of Some Mechanical Properties of Composite Materials with a Dammar-Based Hybrid Matrix and Reinforced by Waste Paper

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1688
Author(s):  
Marius Marinel Stănescu ◽  
Dumitru Bolcu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Volume Ratio ◽  
Tensile Tests ◽  
Sem Analysis ◽  
Waste Paper ◽  
Hybrid Resin ◽  
Natural Resin ◽  
Tensile Response

When obtaining environment-friendly hybrid resins made of a blend of Dammar natural resin, in a prevailing volume ratio, with epoxy resin, it is challenging to find alternatives for synthetic resins. Composite materials reinforced with waste paper and matrix made of epoxy resin or hybrid resin with a volume ratio of 60%, 70% and 80% Dammar were studied. All samples obtained have been submitted to tensile tests and Scanning Electron Microscopy (SEM) analysis. The tensile response, tensile strength, modulus of elasticity, elongation at break and the analysis of the fracture surface were determined. The damping properties of vibrations of bars in hybrid resins and in the composite materials under study were also examined. The mechanical properties of the four types of resins and of the composite materials were compared. The chemical composition for a hybrid resin specimen were obtained using the Fourier Transformed Infrared Spectroscopy (FTIR) and Energy, Dispersive X-ray Spectrometry (EDS) analyzes.

Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin

2015 ◽  
Vol 1088 ◽  
pp. 411-414 ◽  
Author(s):  
Francisco Augusto Zago Marques ◽  
Carlos Eduardo G. da Silva ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Túlio Hallak Panzera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Portland Cement ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Physical And Mechanical Properties ◽  
Response Variable

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

Carbon Fiber Powder Reinforced Epoxy Composites used for Rapid Tooling

2011 ◽  
Vol 287-290 ◽  
pp. 197-200
Author(s):  
Hai Qing Hu ◽  
Li Zhao ◽  
Jia Qiang Liu ◽  
Shi Bao Wen ◽  
Yong Jiang Gu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Rapid Tooling ◽  
Epoxy Composites ◽  
Waste Materials ◽  
Ultrasonic Time ◽  
Good For

Carbon fiber powder (CFP) instead of the traditional glass fiber (cloth) was used to reinforce epoxy resin for rapid tooling. There are two obvious advantages: one is to utilize the waste materials, which is good for the protection of the environment; another is to simplify the producing process by cast molding. The filling amount and dispersing process of CFP was studied in this paper. The results show that when the amount of CFP was 10 wt%, and the ultrasonic time is more than 15 min, the CFP can be dispersed in the epoxy matrix uniformly, and the mechanical properties can meet the requirement of epoxy molding.

Submicron inorganic particles as an additional filler in hybrid epoxy matrix composites reinforced with glass fibres

2019 ◽  
Vol 28 (7) ◽  
pp. 484-491
Author(s):  
Marcin Włoch ◽  
Filip Bagiński ◽  
Piotr Koziński ◽  
Janusz Datta
Keyword(s):  
Mechanical Properties ◽  
Metal Oxide ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
Submicron Particles ◽  
Inorganic Particles ◽  
Glass Composites ◽  
Glass Fibres

In this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous filler) were fabricated by using the hand lay-up method and the average content of glass fibres was 39–41 wt%. Flexural properties, thermo-mechanical properties, abrasion resistance and hardness were determined for each group of the prepared hybrid epoxy/glass composites. The obtained results were compared with control samples (without submicron particles). Investigations showed that the addition of 2 wt% SiO2, 4 wt% TiO2 or 4 wt% ZnO to epoxy resin improved the flexural strength and the flexural modulus of composites. Dynamic mechanical analysis showed that the addition of the mentioned particles enhanced storage and loss modulus. It can be attributed to the good dispersion and good interaction between submicron-mentioned particles and the epoxy matrix.

scholarly journals Improving Mechanical Properties of Thermoset Biocomposites by Fiber Coating or Organic Oil Addition

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Truc T. Ngo ◽  
James G. Kohl ◽  
Tawni Paradise ◽  
Autumn Khalily ◽  
Duane L. Simonson
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Polymer Matrix ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Linseed Oil ◽  
Hemp Fibers ◽  
Fiber Coating ◽  
Strength And Ductility

Two different thermoset biocomposite systems are experimented in this study with the hope to improve their mechanical properties. Fiberglass and hemp, in form of fabrics, are used to reinforce the thermoset polymer matrix, which includes a traditional epoxy resin and a linseed oil-based bioresin (UVL). The fiber/polymer matrix interface is modified using two different approaches: adding a plant-based oil (pine or linseed) to the polymer matrix or coating the fibers with 3-(aminopropyl)triethoxysilane (APTES) prior to integrating them into the polymer matrix. Epoxy resin is cured using an amine-based initiator, whereas UVL resin is cured under ultraviolet light. Results show that hemp fibers with APTES prime coat used in either epoxy or UVL matrix exhibit some potential improvements in the composite’s mechanical properties including tensile strength, modulus of elasticity, and ductility. It is also found that adding oil to the epoxy matrix reinforced with fiberglass mostly improves the material’s modulus of elasticity while maintaining its tensile strength and ductility. However, adding oil to the epoxy matrix reinforced with hemp doubles the material’s ductility while slightly reducing its tensile strength and modulus of elasticity.

Synthesis of UV-Writing Fluorinated Polymer for Organic Optical Waveguide

2013 ◽  
Vol 690-693 ◽  
pp. 1604-1608
Author(s):  
Xu Fei ◽  
Shu Qi Fan ◽  
Jing Tian ◽  
Yi Wang
Keyword(s):  
Refractive Index ◽  
Epoxy Resin ◽  
Polymer Film ◽  
Optical Waveguide ◽  
Optical Waveguides ◽  
Uv Light ◽  
Uv Exposure ◽  
Propagation Losses ◽  
Channel Waveguides ◽  
Uv Writing

UV-Writing Poly(FPS-co-GMA) for optical waveguide was synthesized and the refractive index of the polymer film was tuned in the range of 1.460~1.555 at 1550 nm by mixing with bis-phenol-A epoxy resin. The film, which was made by spinning coated the Poly(FPS-co-GMA) with photo initiator, had good UV light lithograph sensitivity. The optical waveguides with very smooth top surface were fabricated from the resulting polymer by direct UV exposure and chemical development. The propagation losses of the channel waveguides were measured to be below 0.6 dB/cm at 1550 nm.

Assessment of GFRP Mechanical Properties in Order to Determinate Suitability for UAV Components

2020 ◽  
Vol 834 ◽  
pp. 57-66
Author(s):  
Mihaela Raluca Condruz ◽  
Alexandru Paraschiv ◽  
Andreea Deutschlander ◽  
Ionel Mîndru
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Low Velocity Impact ◽  
Small Range ◽  
Low Velocity ◽  
Damage Degree ◽  
Aerial Vehicle ◽  
Twill Weave

Mechanical properties of several composite materials were assessed in order to establish their suitability for unmanned aerial vehicle components manufacturing. The materials under evaluation consisted in E-glass fiber (satin/twill weave) impregnated with polyester, respective epoxy resin. The study was focused on two mechanical tests: low-velocity impact and tensile tests. Based on the results obtained, it was observed that configurations reinforced with twill weave presented higher tensile strength compared with satin reinforced configurations. Moreover, they presented a lower damage degree in case of impact tests. It was concluded that fabric quality has a considerable influence on the impregnation process and on the composite material mechanical properties. In the present case, the twill weave impregnated with epoxy resin can be used to manufacture small range UAV components.

Sign in / Sign up

Export Citation Format

Share Document