Long-term mechanical performance of polyethylene pipe materials in presence of carbon black masterbatch with different carriers

This paper presents a long-term experimental investigation of E-glass/epoxy composites’ durability exposed to seawater at different temperatures. The thermoset composite samples were exposed to 23 °C, 45 °C and 65 °C seawater for a prolonged exposure time of 11 years. The mechanical performance as a function of exposure time was evaluated and a strength-based technique was used to assess the durability of the composites. The experimental results revealed that the tensile strength of E-glass/epoxy composite was reduced by 8.2%, 29.7%, and 54.4% after immersion in seawater for 11 years at 23 °C, 45 °C, and 65 °C, respectively. The prolonged immersion in seawater resulted in the plasticization and swelling in the composite. This accelerated the rate of debonding between the fibers and matrix. The failure analysis was conducted to investigate the failure mode of the samples. SEM micrographs illustrated a correlation between the fiber/matrix debonding, potholing, fiber pull-out, river line marks and matrix cracking with deterioration in the tensile characteristics of the thermoset composite.

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Electrospun PCL Patches with Controlled Fiber Morphology and Mechanical Performance for Skin Moisturization via Long-Term Release of Hemp Oil for Atopic Dermatitis

Membranes ◽

10.3390/membranes11010026 ◽

2020 ◽

Vol 11 (1) ◽

pp. 26

Author(s):

Sara Metwally ◽

Daniel P. Ura ◽

Zuzanna J. Krysiak ◽

Łukasz Kaniuk ◽

Piotr K. Szewczyk ◽

...

Keyword(s):

Mechanical Properties ◽

Atopic Dermatitis ◽

Mechanical Performance ◽

Antibacterial Properties ◽

Skin Condition ◽

Fiber Morphology ◽

Suitable Material ◽

Hemp Oil ◽

Skin Moisture

Atopic dermatitis (AD) is a chronic, inflammatory skin condition, caused by wide genetic, environmental, or immunologic factors. AD is very common in children but can occur at any age. The lack of long-term treatments forces the development of new strategies for skin regeneration. Polycaprolactone (PCL) is a well-developed, tissue-compatible biomaterial showing also good mechanical properties. In our study, we designed the electrospun PCL patches with controlled architecture and topography for long-term release in time. Hemp oil shows anti-inflammatory and antibacterial properties, increasing also the skin moisture without clogging the pores. It can be used as an alternative cure for patients that do not respond to traditional treatments. In the study, we tested the mechanical properties of PCL fibers, and the hemp oil spreading together with the release in time measured on skin model and human skin. The PCL membranes are suitable material as patches or bandages, characterized by good mechanical properties and high permeability. Importantly, PCL patches showed release of hemp oil up to 55% within 6 h, increasing also the skin moisture up to 25%. Our results confirmed that electrospun PCL patches are great material as oil carriers indicating a high potential to be used as skin patches for AD skin treatment.

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Analysis of thermo-mechanical coupling damage behavior in long-term performance of microelectromechanical systems actuators

International Journal of Damage Mechanics ◽

10.1177/10567895211033972 ◽

2021 ◽

pp. 105678952110339

Author(s):

Jiaxing Cheng ◽

Zhaoxia Li

Keyword(s):

Damage Mechanics ◽

Microelectromechanical Systems ◽

Mechanical Performance ◽

Damage Model ◽

Irreversible Damage ◽

Damage Behavior ◽

Thermal Actuators ◽

Long Term Performance ◽

Term Performance

Effective numerical analysis is significant for the optimal design and reliability evaluation of MEMS, but the complexity of multi-physical field couplings and irreversible damage accumulation in long-term performance make the analysis difficult. In the present paper, the continuum damage mechanics method is used to develop a creep damage model and conduct long-term performance analysis for MEMS thermal actuators with coupled thermo-mechanical damage behavior. The developed damage model can make a connection between the material deterioration due to microstructure changes and the macroscopic responses (the change of thermo-mechanical performance or structure failure). The numerical simulations of coupled thermo-mechanical behavior in long-term performance are implemented using the finite element method, which is validated through comparison with previous literature. The numerical results demonstrate that the proposed damage model and numerical method can provide effective assessment in the long-term performance of MEMS thermal actuators.

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Long term mechanical performance of nano-engineered high volume fly ash concrete

Journal of Building Engineering ◽

10.1016/j.jobe.2021.103168 ◽

2021 ◽

pp. 103168

Author(s):

Charith Herath ◽

Chamila Gunasekara ◽

David W. Law ◽

Sujeeva Setunge

Keyword(s):

Fly Ash ◽

Mechanical Performance ◽

High Volume ◽

Fly Ash Concrete ◽

High Volume Fly Ash

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Mechanistic Approach for Long-Term Stability of a Polyethylene Glycol–Carbon Black Nanocomposite Sensor

ACS Sensors ◽

10.1021/acssensors.1c01875 ◽

2021 ◽

Author(s):

Wenjun Li ◽

Kazuki Nagashima ◽

Takuro Hosomi ◽

Chen Wang ◽

Yosuke Hanai ◽

...

Keyword(s):

Polyethylene Glycol ◽

Carbon Black ◽

Term Stability ◽

Long Term Stability ◽

Mechanistic Approach ◽

Nanocomposite Sensor

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The importance of axial misalignment on the long term strength of polyethylene pipe butt fusion joints

Polymer Engineering & Science ◽

10.1002/pen.760291912 ◽

1989 ◽

Vol 29 (19) ◽

pp. 1406-1412 ◽

Cited By ~ 5

Author(s):

Jeremy Bowman ◽

Ravindra Parmar

Keyword(s):

Term Strength ◽

Polyethylene Pipe

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Mechanical Properties of Carbon Black-Filled Polymeric Concrete

Advanced Composites Letters ◽

10.1177/096369359600500405 ◽

1996 ◽

Vol 5 (4) ◽

pp. 096369359600500

Author(s):

L. Rejón ◽

M.A. Ponce ◽

G. Vazquez-Polo ◽

V.M. Castaño

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

Mechanical Performance ◽

Carbon Black Content

Polymeric concrete, a recently patented material for electrical insulators, was modified by using various amounts of monomer in the resins employed and by adding different concentrarions of carbon black. The results show that there exists an optimal carbon black content in terms of the mechanical performance.

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The Influence of Reclaimed Asphalt Pavement on the Mechanical Performance of Bituminous Mixtures. An Analysis at the Mortar Scale

Sustainability ◽

10.3390/su12208343 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8343

Author(s):

Ana E. Hidalgo ◽

Fernando Moreno-Navarro ◽

Raúl Tauste ◽

M. Carmen Rubio-Gámez

Keyword(s):

Mechanical Performance ◽

Asphalt Pavement ◽

Mechanical Analysis ◽

Elastic Response ◽

Reclaimed Asphalt Pavement ◽

Reclaimed Asphalt ◽

Bituminous Mixtures ◽

Water Sensitivity ◽

Term Performance

The main characteristics of bituminous mixtures manufactured with a considerable amount of reclaimed asphalt pavement (RAP), compared to conventional mixtures, are a reduction in workability, an increase in stiffness, and a loss of ductility, due to the presence of the aged bitumen contained in the RAP particles. To minimize these impacts, softer binders or rejuvenators are commonly used in the design of these mixtures in order to restore part of the ductility lost and to reduce the stiffness. In spite of previous investigations demonstrating that the mortar plays an essential role in the workability, long-term performance, and durability of bituminous mixtures (where cracking, cohesion, and adhesion problems all start at this scale), not many studies have assessed the impacts caused by the presence of RAP. In response to this, the present paper analyzes the workability, fatigue performance, and water sensitivity of bituminous mortars containing different amounts of RAP (from 0% to 100%) and rejuvenators. Mortar specimens were compacted using a gyratory compactor and studied via dynamic mechanical analysis under three point bending configuration. The results demonstrated that the presence of RAP reduces the workability and ductility of asphalt mortars. However, it also causes an increase in their stiffness, which induces a more elastic response and causes an increase in their resistance to fatigue, which could compensate for the loss of ductility. This aspect, together with the low water sensitivity shown, when using Portland cement as an active filler, would make it possible to produce asphalt materials with high RAP contents with a similar long-term mechanical performance as traditional ones. In addition, the use of rejuvenators was demonstrated to effectively correct the negative workability and ductility impacts caused by using RAP, without affecting the fatigue resistance and material adhesion/cohesion.

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3D-Printable PP/SEBS Thermoplastic Elastomeric Blends: Preparation and Properties

Polymers ◽

10.3390/polym11020347 ◽

2019 ◽

Vol 11 (2) ◽

pp. 347 ◽

Cited By ~ 18

Author(s):

Shib Banerjee ◽

Stephen Burbine ◽

Nischay Kodihalli Shivaprakash ◽

Joey Mead

Keyword(s):

3D Printing ◽

Carbon Black ◽

Computer Aided Design ◽

Fused Deposition Modeling ◽

Mechanical Performance ◽

Polymeric Materials ◽

Fused Deposition ◽

3D Printed ◽

Injection Molded ◽

Preferential Location

Currently, material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) is considered a highly adaptable and efficient additive manufacturing technique to develop components with complex geometries using computer-aided design. While the 3D printing process for a number of thermoplastic materials using FDM technology has been well demonstrated, there still exists a significant challenge to develop new polymeric materials compatible with ME3DP. The present work reports the development of ME3DP compatible thermoplastic elastomeric (TPE) materials from polypropylene (PP) and styrene-(ethylene-butylene)-styrene (SEBS) block copolymers using a straightforward blending approach, which enables the creation of tailorable materials. Properties of the 3D printed TPEs were compared with traditional injection molded samples. The tensile strength and Young’s modulus of the 3D printed sample were lower than the injection molded samples. However, no significant differences could be found in the melt rheological properties at higher frequency ranges or in the dynamic mechanical behavior. The phase morphologies of the 3D printed and injection molded TPEs were correlated with their respective properties. Reinforcing carbon black was used to increase the mechanical performance of the 3D printed TPE, and the balancing of thermoplastic elastomeric and mechanical properties were achieved at a lower carbon black loading. The preferential location of carbon black in the blend phases was theoretically predicted from wetting parameters. This study was made in order to get an insight to the relationship between morphology and properties of the ME3DP compatible PP/SEBS blends.

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