Accelerated ageing versus realistic ageing in aerospace composite materials. III. The chemistry of thermal ageing in bismaleimide based composites

2007 ◽  
Vol 105 (4) ◽  
pp. 2062-2072 ◽  
Author(s):  
B. Dao ◽  
J. Hodgkin ◽  
J. Krstina ◽  
J. Mardel ◽  
W. Tian
Keyword(s):  
Composite Materials ◽  
Thermal Ageing ◽  
Accelerated Ageing

scholarly journals The Effect of Accelerated Ageing on Reaction-to-Fire Properties–Composite Materials

2021 ◽  
Author(s):  
Anna Sandinge ◽  
Per Blomqvist ◽  
Lars Schiøtt Sørensen ◽  
Anne Dederichs
Keyword(s):  
Composite Materials ◽  
Glass Fibre ◽  
Fibre Composite ◽  
Thermal Ageing ◽  
Gas Analysis ◽  
Accelerated Ageing ◽  
Fire Behaviour ◽  
Increased Temperature ◽  
Fire Properties ◽  
Glass Fibre Composite

AbstractAs material age, the durability, strength, and other mechanical properties are impacted. The lifespan of a material generally decreases when exposed to weathering conditions such as wind, temperature, humidity, and light. It is important to have knowledge of how materials age and how the material properties are affected. Regarding materials´ fire behaviour and the effect of ageing on these properties, the knowledge is limited. The research questions of the current work are: Are the fire properties of composite materials affected by ageing? And if so, how is it affected? The study is on material at Technology Readiness Level 9 (TRL). In this study, three composite fibre laminates developed for marine applications were exposed to accelerated ageing. Two different ageing conditions were selected, thermal ageing with an increased temperature of 90°C and moisture ageing in a moderately increased temperature of 40°C and a relative humidity of 90%. Samples were collected after one, two and four weeks of ageing. The reaction-to-fire properties after ageing was evaluated using the ISO 5660–1 cone calorimeter and the EN ISO 5659–2 smoke chamber with FTIR gas analysis. The test results showed that the fire behaviour was affected. Two of the composite laminates, both phenolic/basalt composites, showed a deteriorated fire behaviour from the thermal ageing and the third composite laminate, a PFA/glass fibre composite, showed an improved fire behaviour both for thermal and moisture ageing. The smoke toxicity was affected by the accelerated ageing, especially for the PFA/glass fibre composite that showed a higher production of CO and HCN, both for the thermal aged and the moisture aged samples.

Role of thermoxidation and depolymerisation in the ageing of systems paper/gum arabic/historical ink

2014 ◽  
Vol 68 (4) ◽  
Author(s):  
András Peller ◽  
Milena Reháková ◽  
Michaela Ciglanská ◽  
Peter Šimon
Keyword(s):  
Reaction Path ◽  
Gum Arabic ◽  
Thermal Ageing ◽  
Accelerated Ageing ◽  
Thermal Method ◽  
Reaction Paths ◽  
Thermal Methods ◽  
Iron Gall ◽  
A Minor ◽  
Whatman Paper

AbstractThe aim of this study was to assess the role and proportional representation of depolymerisation and thermoxidation reaction paths in the systems paper/gum arabic (GA)/historical ink during various accelerated ageing methods. The historical inks under study are iron-gall, bistre, and sepia. The results indicate that thermoxidation represents only a minor reaction path in the ageing of paper/GA/ink systems except for the iron-gall ink and the light-thermal method of accelerated ageing. The iron-gall ink accelerates both reaction paths of ageing, i.e. thermoxidation and depolymerisation; in this case, thermoxidation might become the prevailing degradation reaction path. For the sepia ink, an anti-depolymerisation stabilising effect in thermal methods of ageing has been detected. Considering the thermoxidation reaction path, the results even suggest that a compound preventing thermoxidation is formed during the thermally accelerated ageing in air and in 100 mg L−1 of NO2. In the light-thermal ageing, the most stable sample is the Whatman paper (W)/GA/bistre ink.

scholarly journals Weathering of Antibacterial Melt-Spun Polyfilaments Modified by Pine Rosin

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 876
Author(s):  
Mikko Kanerva ◽  
Jacob Mensah-Attipoe ◽  
Arja Puolakka ◽  
Timo M. Takala ◽  
Marko Hyttinen ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Degradation Process ◽  
Thermal Ageing ◽  
Poly Lactic Acid ◽  
Accelerated Ageing ◽  
Functional Additives ◽  
Volatile Organic ◽  
Melt Spun ◽  
Over Time ◽  
Killing Response

For many antibacterial polymer fibres, especially for those with natural functional additives, the antibacterial response might not last over time. Moreover, the mechanical performance of polymeric fibres degrades significantly during the intended operation, such as usage in textile and industrial filter applications. The degradation process and overall ageing can lead to emitted volatile organic compounds (VOCs). This work focused on the usage of pine rosin as natural antibacterial chemical and analysed the weathering of melt-spun polyethylene (PE) and poly lactic acid (PLA) polyfilaments. A selected copolymer surfactant, as an additional chemical, was studied to better integrate rosin with the molecular structure of the plastics. The results reveal that a high 20 w-% of rosin content can be obtained by surfactant addition in non-oriented PE and PLA melt-spun polyfilaments. According to the VOC analysis, interestingly, the total emissions from the melt-spun PE and PLA fibres were lower for rosin-modified (10 w-%) fibres and when analysed below 60 ℃. The PE fibres of the polyfilaments were found to be clearly more durable in terms of the entire weathering study, i.e., five weeks of ultraviolet radiation, thermal ageing and standard washing. The antibacterial response against Gram-positive Staphylococcus aureus by the rosin-containing fibres was determined to be at the same level (decrease of 3–5 logs cfu/mL) as when using 1.0 w-% of commercial silver-containing antimicrobial. For the PE polyfilaments with rosin (10 w-%), full killing response (decrease of 3–5 logs cfu/mL) remained after four weeks of accelerated ageing at 60 ℃.

Accelerated Ageing of Parchment: Investigation of a Photo Catalysed, Low-Heat Approach

2018 ◽  
Vol 39 (1) ◽  
pp. 33-70 ◽  
Author(s):  
Marie Sarah Kern ◽  
Andrea Pataki-Hundt ◽  
Jan Wouters ◽  
Daniel P. Kirby
Keyword(s):  
Moisture Absorption ◽  
Thermal Ageing ◽  
Absorption Capacity ◽  
Accelerated Ageing ◽  
Heat Sensitivity ◽  
Shrinkage Temperature ◽  
Art And Design ◽  
Bovine Hide ◽  
Ma Thesis ◽  
Structural Levels

Abstract Accelerated ageing is an often-used tool in conservation research, yet difficult to apply to parchment due to the materials inherent heat sensitivity. The complexity of this organic material makes the analysis of its deterioration especially challenging. An attempt to develop a non-heat ageing protocol for parchment is described in this paper. The work was performed within the scope of a MA-thesis at the State Academy of Art and Design Stuttgart. Samples of a modern new limed goat parchment and pieces of reconstituted parchment made from bovine hide powder were subjected to a combination of light ageing and dynamic ageing at moderate temperatures. All samples were analysed with the goal to observe degradation on as many structural levels as possible: colour measurement via VIS spectrometry and light-microscopic observation of fibre damage were employed to assess visible changes. Shrinkage temperature (Ts) was measured as an indicator for the amount of intact intrafibrillar bonds and the determination of the maximum moisture absorption capacity gave an impression on the parchments overall level of hygroscopy. In addition, PMF (Peptid Mass Fingerprinting) via MALDI/MS TOF was performed on extracts from unaged and light aged goat parchment. The results of the different types of analysis showed significant degradation on different structural levels of the parchment, indicating that accelerated ageing of parchment that uses a combination of light and dynamic ageing may be a viable alternative to the more commonly applied thermal ageing.

The necessity of accelerated ageing in fire performance assessments of composite materials

2021 ◽  
Vol 141 ◽  
pp. 105358
Author(s):  
Anna Sandinge ◽  
Per Blomqvist ◽  
Anne Dederichs ◽  
Frank Markert
Keyword(s):  
Composite Materials ◽  
Performance Assessments ◽  
Accelerated Ageing ◽  
Fire Performance ◽  
In Fire

scholarly journals Experimental Investigation on Vegetative Oils under Accelerated Thermal Ageing against Their Dielectric Strength

2017 ◽  
Vol 7 (3) ◽  
pp. 1588
Author(s):  
Siti Sufiah Abd Wahid ◽  
Mohd Fikri Hilmi Mohd Taib ◽  
Yanuar Z. Arief ◽  
Mohd Hafizi Ahmad ◽  
Noor Azlinda Ahmad ◽  
...  
Keyword(s):  
Power Transformer ◽  
Research Work ◽  
Dielectric Strength ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Transformer Oil ◽  
Accelerated Ageing ◽  
Insulation Material ◽  
Low Dielectric ◽  
High Dielectric

Insulation is one of the most important parts in high voltage apparatus such as power transformer. Most power transformer use liquid insulation material, known as power transformer oil. Petroleum-based oil so called mineral oil has been used for many years as power transformer oil. This is due to its high dielectric field strength, low dielectric loses and good long-term performance. This research work has been carried out to investigate the effect of thermal accelerated ageing on electrical properties for several vegetative-based oils. The oil samples that have been used in this research work are soy bean-based oil (FR3) and commercial palm-based oil (PFAE). As comparison, Hyrax mineral oil has also been investigated. The results revealed that vegetative-based oils have as well as dielectric strength compared with mineral oil.  It was found that the dielectric strength for all oil samples decreased when undergo the thermal accelerated ageing process.

Influence of Chemical Treatment on Chemical Changes of Fir Wood

2016 ◽  
Vol 688 ◽  
pp. 38-43
Author(s):  
Tereza Tribulová ◽  
František Kačík ◽  
Dmitry V. Evtuguin ◽  
Iveta Čabalová
Keyword(s):  
Chemical Treatment ◽  
Treated Wood ◽  
Thermal Ageing ◽  
Hot Water ◽  
Accelerated Ageing ◽  
Sufficient Information ◽  
Structural Components ◽  
Wood Degradation ◽  
Negative Effect

Many chemicals are used to prolong wood lifetime and protect wood against wood-destroying organisms and fire but there is not sufficient information about their possible corrosive effects on wood and its structural components from the perspective of long-term exposition in unsuitable condition. This study evaluated the combined effects of inorganic chemicals (borates, phosphates containing ammonia, sulphates with metal cations, chlorides) and wet-thermal accelerated ageing (T=80 °C, RH=65 %, for 30 days) on chemical composition of treated wood. Used analyses indicated that selected chemicals cause a decomposition of all wood constituents in varying degrees. Cellulose was degraded in the greatest extent due to acidic sulphates (Fe3+, Cu2+) and almost no deterioration of polysaccharides was caused with H3BO3. A negative effect on lignin had almost only Na2B4O7.10H2O and NaCl. At the same time the amount of extractives in hot water and acetone and ash content were compared at all samples. The wet-thermal ageing played an important role in wood degradation, but the effect of chemical treatment was certainly stronger.

Comparative Studies on the Thermal Ageing of Some Painting Materials

2018 ◽  
Vol 55 (2) ◽  
pp. 168-175
Author(s):  
Traian Rus ◽  
Adriana Mariana Bors ◽  
Alina Ruxana Caramitu ◽  
Iosif Lingvay ◽  
Danut Ionel Vaireanu
Keyword(s):  
Structural Changes ◽  
Thermal Stresses ◽  
Industrial Applications ◽  
Thermal Ageing ◽  
Accelerated Ageing ◽  
Clear Correlation ◽  
Dielectric Losses ◽  
Thermal Treatments ◽  
Thermal Cycles ◽  
Painting Materials

This paper presents a comparative study with respect to the behavior of some painting materials, used mainly for decorative and protective industrial applications, exposed to a controlled accelerated ageing process by using thermal storage and successive thermal cycles. The evaluation of the structural changes, as well as those concerning the dielectric loss were carried out in a comparative manner, on the initial samples, before any exposure to thermal stresses and during the ongoing process of the thermal treatments applied. As analysis techniques coupled thermal analysis and dielectric impedance spectroscopy have been used. It was found that there is a clear correlation between the structural changes of the investigated materials, particularly in the case of the epoxy materials subjected to the applied thermal treatments and the evolution of the dielectric losses in the material. As a result of these investigations, one may determine the characteristic acceptable zones for the thermal stresses (up to 1300 h of storage and 1500 thermal cycles), anything above these boundaries leading to strong increases in the dielectric losses and hence the deterioration of the materials rendered unfit to be used for the intended purpose.

Study on Anti-Aging Performance of Composite Materials of PP-G-an /PP /SiO2

2013 ◽  
Vol 634-638 ◽  
pp. 2023-2027 ◽  
Author(s):  
Ya Zhen Wang ◽  
Yong Li ◽  
Wei Nan Jia ◽  
Cheng E Yue ◽  
Di Ma
Keyword(s):  
Carbon Dioxide ◽  
Composite Materials ◽  
Supercritical Carbon Dioxide ◽  
Accelerated Ageing ◽  
Ageing Test ◽  
Aging Mechanism ◽  
Aging Properties ◽  
Aging Property ◽  
Ft Ir ◽  
Grafting Copolymerization

In order to further improve the anti-aging properties of polypropylene (PP), the polypropylene (PP) was modified via Supercritical carbon dioxide (SC CO2) grafting copolymerization with AN. PP-g-AN characterized by FT-IR. Polypropylene grafted acrylonitrile (PP-g-AN) / polypropylene (PP) / silica (SiO2) were blended. The influence of the contents of PP-g-AN on the anti-aging property was discussed. At the same time, the anti-aging mechanism was studied. After the artificial accelerated ageing test, the result shows that the anti-aging properties of PP were improved greatly which due to the addition of PP-g-AN and SiO2．

Sign in / Sign up

Export Citation Format

Share Document