Influence of sulfuric acid bath on morphological structure and mechanical properties of poly(p-phenylene-1,3,4-oxadiazole) fibers

2009 ◽  
Vol 114 (3) ◽  
pp. 1485-1493 ◽  
Author(s):  
Zaixing Zhang ◽  
Guangdou Ye ◽  
Wentao Li ◽  
Ting Li ◽  
Jianjun Xu
Keyword(s):  
Mechanical Properties ◽  
Sulfuric Acid ◽  
Morphological Structure ◽  
Acid Bath

Mechanical properties of the tracheal mucosal membrane in the rabbit. II. Morphometric analysis

2000 ◽  
Vol 88 (3) ◽  
pp. 1022-1028 ◽  
Author(s):  
Lu Wang ◽  
Kenneth L. Pinder ◽  
Joel L. Bert ◽  
Mitsushi Okazawa ◽  
Peter D. Paré
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Mechanical Load ◽  
Morphological Structure ◽  
Longitudinal Direction ◽  
Smooth Muscle Contraction ◽  
Elastic Fibers ◽  
Tissue Samples ◽  
Mucosal Membrane ◽  
Simple Geometry

Folding of the airway mucosal membrane provides a mechanical load that impedes airway smooth muscle contraction. Mechanical testing of rabbit tracheal mucosal membrane showed that the membrane is stiffer in the longitudinal than in the circumferential direction of the airway. To explain this difference in the mechanical properties, we studied the morphological structure of the rabbit tracheal mucosal membrane in both longitudinal and circumferential directions. The collagen fibers were found to form a random meshwork, which would not account for differences in stiffness in the longitudinal and circumferential directions. The volume fraction of the elastic fibers was measured using a point-counting technique. The orientation of the elastic fibers in the tissue samples was measured using a new method based on simple geometry and probability. The results showed that the volume fraction of the elastic fibers in the rabbit tracheal mucosal membrane was ∼5% and that the elastic fibers were mainly oriented in the longitudinal direction. Age had no statistically significant effect on either the volume fraction or the orientation of the elastic fibers. Linear correlations were found between the steady-state stiffness and the quantity of the elastic fibers oriented in the direction of testing.

Highly gas permselective polyetherketone hollow fibre membranes using aqueous sulfuric acid solution as coagulant

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiping Yang ◽  
Philip J Brown
Keyword(s):  
Mechanical Properties ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Gas Separation ◽  
Sulfuric Acid Solution ◽  
Hollow Fibre ◽  
Injection Rate ◽  
Fluid Injection ◽  
Aqueous Sulfuric Acid ◽  
Membrane Morphology

AbstractHollow fibre membranes with more sponge-like morphology and improved gas permeation performance were spun from 20% polyetherketone (PEK) /sulfuric acid (H2SO4) dope solution with aqueous sulfuric acid solution as coagulant using dry-jet wet spinning process. The membrane morphology, mechanical properties and gas separation performance (hydrogen, methane and carbon dioxide) of as-spun PEK hollow fibres have been measured using SEM, Instron and gas test rig. Better cross section structures and mechanical properties in as-spun PEK hollow fibres were observed when aqueous sulfuric acid solution replaced water as coagulant (internal and external). The hydrogen/methane selectivity of up to 40 and hydrogen permeation rate of 3.65 GPU obtained in PEK hollow fibre membranes using 30% sulfuric acid solution as internal and external coagulant simultaneously at the bore fluid injection rate of 30 ml/h are higher than those reported in literatures. Furthermore the effects of bore fluid injection rate and various coagulants on the membrane morphology, mechanical properties and gas separation properties were investigated, as well.

scholarly journals Highly Molybdenum-Alloyed Materials Hastelloy BC-1 (2.4708) and B3 (2.4600): Diffusion Bonding Experiments and Evaluation of both Mechanical Behavior and Corrosion Resistance in Hot 70% Sulfuric Acid

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 376
Author(s):  
Thomas Gietzelt ◽  
Mario Walter ◽  
Volker Toth ◽  
Florian Messerschmidt ◽  
Ralf Dahm
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Diffusion Bonding ◽  
Tensile Tests ◽  
Raw Material ◽  
Significant Advance ◽  
Thin Walls ◽  
Corrosive Effect ◽  
Material Conditions

Sulfuric acid is a widely used raw material in the chemical industry. Its corrosive effect on materials varies considerably, depending on impurities, temperature and water content. This is an issue for micro process apparatuses with thin walls. Such devices are often joint by diffusion bonding what may alter materials properties due to high temperatures and long dwell times. In this paper, two high molybdenum alloys, namely Hastelloy B3 and BC-1, were investigated. Diffusion bonding tests were performed at different temperatures. Tensile tests were carried out for different material conditions, to determine the change in mechanical strength and elongation at fracture values. The fracture behavior of both alloys was ductile and the fracture surfaces showed dimple structure. For diffusion bonded samples, weak spots or rather non-bonded areas were found. These obviously caused the onset of material failure and thus, degradation of mechanical properties. Tensile samples, aged in 70% sulfuric acid at 100 °C for 1000 h showed local corrosion attacks at the grain boundaries at the circumferential surfaces and joining planes—for Hastelloy B3 more pronounced than for Hastelloy BC-1. Accordingly, a further decrease of stress and elongation at fracture values was observed. However, 0.2% yield strength used for dimensioning components are found to be reasonable. As conclusion, at least Hastelloy BC-1 reveals both good mechanical properties and an excellent corrosion resistance, regardless of the heat treatment. This is a significant advance compared to the results obtained from a previously research project on four different alloys.

Fabrication and Mechanical Properties of Double-Shell Thermal Energy Storage Microcapsules Applied as Environmental Temperature-Controlling Materials in Building

2010 ◽  
Vol 96 ◽  
pp. 81-86 ◽  
Author(s):  
Jun Feng Su ◽  
Sheng Bao Wang ◽  
Zhen Huang
Keyword(s):  
Mechanical Properties ◽  
Energy Storage ◽  
Shell Structure ◽  
Environmental Temperature ◽  
Morphological Structure ◽  
Average Diameter ◽  
Formaldehyde Resin ◽  
Plastic Behavior ◽  
Shell Analysis ◽  
Change Temperature

The aim of the present work was to fabricate heat energy storage microcapsules, which could be used in indoor-wall materials as environmental temperature-controller. Melamine formaldehyde resin (MF) double-shell structure microcapsules were fabricated and the mechanical properties of shell were investigated. The average diameter of microcapsules was in the range of 5-10 μm, and the globular surface was smooth and compact. The mechanical properties of shell were evaluated through observing the surface morphological structure change after pressure by means of scanning electron microscopy (SEM). The results showed that a yield point was found both on single and double shell, and when the press was beyond the point the microcapsules showed plastic behavior. In addition, the mechanical intensity of double-shell microcapsules was better than that of single shell. Analysis of DSC indicated that the phase change temperature was not affected by the double –shell structure.

Mechanical properties and durability of unconfined and confined geopolymer concrete with fiber reinforced polymers exposed to sulfuric acid

2019 ◽  
Vol 215 ◽  
pp. 1015-1032 ◽  
Author(s):  
Radhwan Alzeebaree ◽  
Abdulkadir Çevik ◽  
Behzad Nematollahi ◽  
Jay Sanjayan ◽  
Alaa Mohammedameen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sulfuric Acid ◽  
Fiber Reinforced Polymers ◽  
Geopolymer Concrete ◽  
Fiber Reinforced ◽  
Reinforced Polymers

Direct polymer additive tooling – effect of additive manufactured polymer tools on part material properties for injection moulding

2019 ◽  
Vol 25 (10) ◽  
pp. 1575-1584 ◽  
Author(s):  
Achim Kampker ◽  
Johannes Triebs ◽  
Sebastian Kawollek ◽  
Peter Ayvaz ◽  
Tom Beyer
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Tensile Elongation ◽  
Morphological Structure ◽  
Mould Insert ◽  
Content Type ◽  
3D Print ◽  
Standard Specimens

Purpose This study aims to investigate the influence of additive manufactured polymer injection moulds on the mechanical properties of moulded parts. Therefore, polymer moulds are used to inject standard specimens to compare material properties to specimens produced using a conventional aluminium tool. Design/methodology/approach PolyJet technology is used to three-dimensional (3D)-print a mould insert in Digital ABS and selective laser sintering (SLS) technology is used to 3D-print a mould insert in polyamide (PA) 3200 GF. A conventionally aluminium milled tool serves as reference. Standard specimens are produced to compare resulting mechanical properties, shrinkage behaviour and morphology. Findings The determined material characteristics of the manufactured prototypes from the additive manufactured tools show differences in terms of mechanical behaviour to those from the aluminium reference tool. The most significant differences are an up to 25 per cent lower tensile elongation and an up to 63 per cent lower elongation at break resulting in an embrittlement of the specimens produced. These differences seem to be mainly due to the different morphological structure caused by the lower thermal conductivity and greater surface roughness of the polymer tools. Research limitations/implications The determined differences in mechanical behaviour can partly be assigned to differences in surface roughness and morphological structure of the resulting parts. The exact extend of either cause, however, cannot be clearly determined. Originality/value This study provides a comparison between the part material properties from conventionally milled aluminium tools and polymer inserts manufactured via additive tooling.

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