scholarly journals The Impact of Modification of Epoxy Adhesive by Addition of Active Diluent on its Energetic and Adhesive Properties

2018 ◽  
Vol 12 (1) ◽  
pp. 19-25
Author(s):  
Anna Krawczuk ◽  
Jacek Domińczuk
Keyword(s):  
Epoxy Adhesive ◽  
Adhesive Properties ◽  
Active Diluent ◽  
The Impact

Recent data on the causative agent of pale green dwarf (Acholeplasma laidlawii var. granulum incertae sedis) in Ukraine: pathogenicityand virulence factors and host reactions

2015 ◽  
Vol 2 (1) ◽  
pp. 30-34
Author(s):  
K. Korobkova ◽  
V. Patyka
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Proteolytic Enzymes ◽  
Physiological State ◽  
Plant Cells ◽  
Temporary Increase ◽  
Adhesive Properties ◽  
The Impact ◽  
Signaling Interactions ◽  
Pale Green

Contemporary state of the distribution of mycoplasma diseases of cultivated crops in Ukraine was analyzed. The changes of the physiological state of plant cells under the impact of mollicutes were investigated. It was demonstrated that there is temporary increase in the activity of peroxidase, catalase, polyphenoloxidase, phenylalanine-ammonia-lyase at the early stages of interaction. The adhesive properties are changed in the mollicutes under the impact of plant lectin; there is synthesis of new polypeptides. It was determined that the phytopathogenic acholeplasma is capable of producing a complex of proteolytic enzymes into the culture me- dium. It was concluded that when plant cells are infected with acholeplasma, a number of signaling interactions and metabolic transformations condition the recognition of pathogenesis and ensure the aggregate response of a plant to stress in the form of defense reactions. It was assumed that some specifi cities of the biology of phy- topathogenic acholeplasma determine their avoiding the immune mechanisms of plants and promote long-term persistence of mollicutes.

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

scholarly journals Experimental and Numerical Peeling Investigation on Aged Multi-Layer Anti-Shatter Safety Films (ASFs) for Structural Glass Retrofit

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 162
Author(s):  
Silvana Mattei ◽  
Luca Cozzarini ◽  
Chiara Bedon
Keyword(s):  
Young Modulus ◽  
Adhesive Layer ◽  
Experimental Program ◽  
Fe Model ◽  
Structural Glass ◽  
Adhesive Properties ◽  
Test Protocol ◽  
Adhesion Properties ◽  
The Impact ◽  
Pet Films

Anti-shatter safety films (ASFs) are often used for structural glass applications. The goal is to improve the response of monolithic elements and prevent fragments from shattering. Thus, the main reason behind their use is the possibility to upgrade safety levels against the brittle failure of glass and minimize the number of possible injuries. However, the impact response of glass elements bonded with Polyethylene terephthalate (PET)-films and pressure sensitive adhesives (PSAs) still represents a research topic of open discussion. Major challenges derive from material characterization and asymmetrical variability under design loads and ageing. In particular, the measurement of interface mechanical characteristics for the adhesive layer in contact with glass is a primary parameter for the ASF choice optimization. For this reason, the present paper presents an experimental campaign aimed at calibrating some basic mechanical parameters that provide the characterization of constitutive models, such as tensile properties (yielding stress and Young modulus) for PET-film and adhesive properties for PSA (energy fracture and peel force). In doing so, both tensile tests for PET-films and peeling specimens are taken into account for a commercially available ASF, given that the peeling test protocol is one of most common methods for the definition of adhesion properties. Moreover, an extensive calibration of the Finite Element (FE) model is performed in order to conduct a parametric numerical analysis of ASF bonded glass solutions. Furthermore, a Kinloch approach typically used to determine the fracture energy of a given tape by considering a variable peel angle, is also adopted to compare the outcomes of calibration analyses and FE investigations on the tested specimens. Finally, a study of the effect of multiple aspects is also presented. The results of the experimental program and the following considerations confirm the rate dependence and ageing dependence in peel tests.

scholarly journals The impact resistance of CTBN- modified epoxy adhesive joints

1994 ◽  
Vol 04 (C8) ◽  
pp. C8-771-C8-776 ◽  
Author(s):  
J. L. Lataillade ◽  
D. Grapotte ◽  
F. Cayssials
Keyword(s):  
Impact Resistance ◽  
Epoxy Adhesive ◽  
Adhesive Joints ◽  
The Impact ◽  
Modified Epoxy

scholarly journals Effect of incorrect mix ratio on strength of two component adhesive Butt-Joints tested at elevated temperature

2018 ◽  
Vol 244 ◽  
pp. 01019
Author(s):  
Jakub Szabelski
Keyword(s):  
Elevated Temperature ◽  
Material Properties ◽  
Mixed Type ◽  
Epoxy Adhesive ◽  
Future Research ◽  
Butt Joints ◽  
Adhesive Material ◽  
Epoxy Adhesives ◽  
Two Component ◽  
The Impact

The aim of this study was to determine the impact of the incorrect mix ratio on the strength of joints bonded with a commercial epoxy adhesive compo-sition. The performance of cold-cured as well as accelerated cured butt joints was monitored at elevated temperature conditions. The obtained data was subjected to statistical analysis to show the correlation between joint strength at high temperature and incorrect mix ratio. The degradation of adhesive material properties with increase of hardener ratio in adhesive material was observed, as well as the change in failure type from mixed type to clearly cohesive (for inadequate volume of harde-ner) or adhesive (for excessive amount of hardener). Surprisingly insufficiency of hardener doesn’t affect the strength of joint in such manner. General recommend-dation were drawn for the preparation of two-component epoxy adhesives for joints to be used in elevated temperature, particularly when uncertainty regarding the correct resin/hardener mix ratio and future research was planned.

scholarly journals Dynamic Mechanical Properties of Oxide Films Formed on Metallic Surfaces as Measured Using a Tribological Approach at High Temperature

2011 ◽  
Vol 2011 ◽  
pp. 1-12
Author(s):  
Yoshinori Isomoto Oka ◽  
Toshinori Tsumura
Keyword(s):  
High Temperature ◽  
Metal Surfaces ◽  
Oxide Films ◽  
Dynamic Mechanical Properties ◽  
Material Surface ◽  
Metallic Surfaces ◽  
Adhesive Properties ◽  
Mechanical Removal ◽  
Barrier Coating ◽  
The Impact

The surface degradation of metals in boiler tubes and turbines in high-temperature corrosive environments causes severe problems in fuel combustion power plant systems. High-temperature resistant materials have been recently developed using a thermal barrier coating (TBC) and high-chromium alloys. Oxide films or coatings formed on metal surfaces at high temperatures can sometimes decrease the corrosion rate. However, the damage to the material is often accelerated by the mechanical removal of corrosion products from the material surface. It is therefore very important to investigate the mechanical and adhesive properties of the oxide films or coatings on metal surfaces used in high-temperature environments. This paper introduces a tribological method that uses a single spherical projectile impact at high temperature to measure the mechanical and adhesive properties of oxide films formed on various metal surfaces. Impact tests were performed on the surfaces of oxide films after their growth in a high-temperature furnace, and the deformed or fractured surfaces were observed in order to measure the mechanical and adhesive properties. The mechanical and adhesive properties of an elastic modulus, fracture, and exfoliation stresses were measured using the impact method, and the results depended on the type of metal oxide films and on the high-temperature environment.

Strength of Adhesive Joints Under Impact Stress Conditions

2006 ◽  
Author(s):  
Luca Goglio ◽  
Massimo Rossetto
Keyword(s):  
Epoxy Adhesive ◽  
Structural Stress ◽  
Bonded Joints ◽  
Tensile Shear ◽  
Impact Stress ◽  
Steel Strips ◽  
Dynamic Loading Condition ◽  
The Impact ◽  
Stress Combinations ◽  
Strength Of Adhesive Joints

The paper reports an experimental study on the bonded joints, carried out by means of an instrumented impact pendulum, equipped to load overlap specimens in tensile shear. Such testing configuration is the most adequate and natural to study the possible modifications of the behavior of the joint, changing from static to dynamic loading condition, keeping the same specimen type. The specimens were steel strips bonded by an epoxy adhesive (Hysol 3425). Several values of lap length, adhesive and adherends thickness were adopted, to achieve rupture under different stress combinations. The stress state at rupture has been calculated by means of a structural solution. The results show that it is possible to represent the failure condition on a chart having as axes the peel and shear structural stress, in a way similar to that found for static cases. Furthermore, in spite of the concerns associated with the impact condition, the strength of the adhesive does not decrease with respect to the case of static loading.

Preliminary Structure Characterization of UV Curing Paint Film

2015 ◽  
Vol 1120-1121 ◽  
pp. 49-52
Author(s):  
Jing Jing Qi ◽  
Mao Bing Shuai ◽  
Yuan Lin Zhou ◽  
Feng Wen Chang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Paint Film ◽  
Uv Curing ◽  
Structure Characterization ◽  
Good Adhesion ◽  
Adhesive Properties ◽  
Liquid Chromatograph ◽  
Low Surface Energy ◽  
The Impact

PC film has some shortcomings such as low surface energy and strong rigidity. In order to improve the impact strength and adhesive properties of PC film, UV curing coating which was used on the surface of the PC film achieved good results. However, the combination between the UV curing paint-PC composite membrane had not been explained clearly. In this paper, we analyzed the structure of UV curing varnish oligomers. Fourier Transform Infrared Spectroscopy (FTIR) 、X-ray Photoelectron Spectroscopy (XPS) and Liquid Chromatograph Mass Spectrometer (LC-MS) were used to characterize. Through the experiment, we had achieved 4, 4’ -Isopropyliden-edicyclohexanol(HBPA) and Phthalic acid . The existence of the two substances explained the reason why the lacquer had good adhesion, and the result also laid the foundation for the the characterization of the molecular structure about the film later.

scholarly journals Challenges in Experimental Evaluation of Morphological, Chemo-Mechanical and Adhesive Properties of Glass-ionomer Based Dental Materials

2019 ◽  
Vol 44 (2) ◽  
pp. 26-30
Author(s):  
Bojan Petrović ◽  
Evgenija Marković ◽  
Tamara Perić ◽  
Sanja Kojić
Keyword(s):  
Critical Review ◽  
Experimental Evaluation ◽  
Dental Materials ◽  
Experimental Studies ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Adhesive Properties ◽  
Dental Tissues ◽  
New Material ◽  
The Impact

Changes in composition and new material characteristics require verification in clinical and experimental studies. Investigating glass-ionomer cements under laboratory conditions encounters problems in interpreting the results and in comparing them with other types of materials tested in the same way. As the connection between the glass-ionomer cements and the dental tissues is delicate, it is often the case that the impact of fractures and other artifacts is either underestimated or over-dimensioned when interpreting the results. A critical review was performed, with defining the main problems regarding the usage of SEM, EDX and nanoindentation techniques in glass-ionomer based materials evaluation.

scholarly journals Effects of Various Antifouling Coatings and Fouling on Marine Sonar Performance

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 663 ◽  
Author(s):  
Bradley Donnelly ◽  
Ian Bedwell ◽  
Jim Dimas ◽  
Andrew Scardino ◽  
Youhong Tang ◽  
...  
Keyword(s):  
Failure Modes ◽  
Transmission Loss ◽  
Fuel Efficiency ◽  
Peel Test ◽  
Acoustic Properties ◽  
Frictional Drag ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Antifouling Coatings ◽  
The Impact

There is a rising imperative to increase the operational availability of maritime vessels by extending the time between full docking cycles. To achieve operational efficacy, maritime vessels must remain clear of biological growth. Such growth can cause significant increases in frictional drag, thereby reducing speed, range and fuel efficiency and decreasing the sensitivity of acoustic sensors. The impact that various stages of fouling have on acoustic equipment is unclear. It is also unclear to what extent antifouling techniques interfere with the transmission of acoustic signals. In this study, to examine this effect, neoprene samples were coated with three antifouling coatings, namely, Intersmooth 7460HS, HempaGuard X7 and Hempasil X3. Other neoprene samples were left uncoated but were imbedded with the biocide, 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) during the mixing and curing process. Uncoated nitrile samples that had varying levels of fouling from immersion in Port Phillip Bay, Australia, for 92, 156 and 239 days were also extracted. The acoustic properties of these samples were measured using an acoustic insertion loss test and compared to uncoated neoprene or nitrile to ascertain the acoustic effects of the applications of antifouling coatings as well as the fouling growth itself. A T-peel test was performed on all coated samples in an attempt to understand the adhesive properties of the coatings when applied to neoprene. It was found that the application of antifouling coatings had little effect on the transmission characteristics of the neoprene with approximately 1 dB loss. The embedment of DCOIT, however, has a chance of causing aeration in the neoprene, which can heavily hamper transmission. An assessment of the effect of the fouling growth found that light and medium fouling levels produced little transmission loss, whereas more extreme fouling lead to a 9 dB transmission loss. The adhesion properties of the coatings were investigated but not fully ascertained as tensile yielding occurred before peeling. However, various failure modes are presented and discussed in this study.

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