Shear strength of homopolymer and copolymer aramid fibers

Şahin, Korhan; Clawson, Jan K.; Singletary, J.; Chasiotis, Ioannis

doi:10.1016/j.polymer.2019.122034

Cited by 12 publications

(8 citation statements)

References 62 publications

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“…The PDA powder reveals peaks at 1515 and 1605 cm −1 which are consistent with the indole or indoline structure proposed earlier. [29] Since there is no shift of the peak position in the infrared spectrum, and there are benzene rings in dopamine and the structural units of Kevlar (-[-CO-C 6 H 4 -CONH-C 6 H 4 -NH-]-), [30] it is speculated that there are van der Waals force, π-π bond, cation-π interaction [31][32][33][34] between dopamine and ANFs. It was observed that the PDA was depolymerized successfully from the PANF film (Figures S3 and S4, Supporting Information) when the PANF film was soaked into alkaline, which indicates that there are no chemical bonds existed between PDA and ANF.…”

Section: Resultsmentioning

confidence: 99%

Flame‐Retardant Host–Guest Films for Efficient Thermal Management of Cryogenic Devices

Yang

Lyu

Chen

et al. 2021

Adv Funct Materials

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Phase change materials hold tremendous potential for thermal energy storage and temperature management due to their high latent heat and chemical stability. However, the manufacture of flame-retardant, form-stable phase change films working under a cryogenic environment remains difficult. Herein, an organic polydopamine-aramid nanofiber (PANF) aerogel film with a limiting oxygen index (LOI) of 32 is applied as a host to confine a unique phase change guest material (i.e., deep eutectic solvent, DES) to fabricate PANF-DES host-guest flame-retardant cryogenic phase change films. The PANF aerogel film is prepared through the in situ polymerization of dopamine within the aramid nanofiber hydrogel film, exhibiting a high specific surface area of 289 m 2 g −1 . The cryogenic phase change material is a ternary DES composed of ammonium chloride (NH 4 Cl), ethylene glycol (Eg), and deionized water (H 2 O). The as-prepared PANF-DES host-guest films with the phase transition temperature of −21 °C and melting enthalpy of 225 J g −1 can withstand fire for 60 s without naked flame, and the peak of heat release rate (pkHRR) is only 26.0 MJ kg −1 . This study opens the way for developing ultra-low flammable phase change composite films, as well as shows great potential applications for thermal management in cryogenic devices.

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Section: Resultsmentioning

confidence: 99%

Flame‐Retardant Host–Guest Films for Efficient Thermal Management of Cryogenic Devices

Yang

Lyu

Chen

et al. 2021

Adv Funct Materials

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“…For r u 12 ¼100 MPa, the debonding length is about 35 nm ($24 r CNT ). Thus, increasing the interfacial peak traction, or interfacial shear strength (IFSS), does not lead to a reinforcement of the polymer fibre because the limiting factor is not interfacial adhesion but the shear strength of the anisotropic polymer fibre itself, being typically very low (10-30 MPa) for UHMWPE fibres or fairly low for PBO or PPTA (40-80 MPa) [39,88,100]. Interestingly, from this work it can be concluded that the same property that limits the shear strength of macroscopic UHMWPE/epoxy or aramid/epoxy composites [88,[102][103][104], limits the reinforcing efficiency of CNT reinforced UHMWPE or aramid nanocomposite fibres.…”

Section: Finite Element Resultsmentioning

confidence: 99%

“…As a result of this, the transverse and shear properties of these fibres can be up to two orders of magnitude lower than their uniaxial tensile properties. Realistic values for the intrinsic shear strength lie somewhere between 10 and 30 MPa for UHMWPE fibres and 60 and 80 MPa for aramid [39,88,100], with PBO somewhere in between. Hence, irrespective of the level of interfacial adhesion the stress transfer in these fibres is often limited by the intrinsic shear strength of the polymer fibre rather than that of the interface.…”

Section: Aligned Cnts Of Finite Lenght In a Polymer Fibre With Debondingmentioning

confidence: 98%

On the low reinforcing efficiency of carbon nanotubes in high-performance polymer fibres

Goutianos

Peijs

2021

Nanocomposites

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Driven by the exceptionally high mechanical properties of carbon nanotubes (CNTs), over the years an extensive research effort has been devoted to the reinforcement of high-performance polymer fibres with CNTs. However, to date, improvements in the strength of these fibres have been rather modest even for relatively high CNT contents. After a brief review of CNT reinforced polymer fibres, here, analytical and numerical finite element models will be used to show that these experimental findings are to be expected based on the intrinsic mechanical properties of these polymer fibres and CNTs, their aspect ratio and interfacial characteristics. Results show that for realistic CNT contents and aspect ratios, the extraordinary strength of CNTs cannot be easily fully exploited in high-performance polymer fibres like Dyneema V R or Kevlar V R . Even if CNTs are perfectly aligned, bonded and dispersed, the low intrinsic shear strength of these highly anisotropic polymer fibres limits effective stress transfer and nanotube reinforcement.

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“…The main use of aramid fiber is in the airplane and military industries, such as ballistic composites and ballistic-rated body armor fabric [ 35 ]. Also, other applications like bulletproof vests, boats, motorsports, protective gloves, and racing car body components are quite widespread [ 36 , 37 , 38 ]. Figure 3 shows the main applications of AR fiber [ 39 ].…”

Section: Types Of Synthetic Fibersmentioning

confidence: 99%

A Review on Synthetic Fibers for Polymer Matrix Composites: Performance, Failure Modes and Applications

Rajak¹,

Wagh²,

Linul

2022

Materials

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In the last decade, synthetic fiber, as a reinforcing specialist, has been mainly used in polymer matrix composites (PMC’s) to provide lightweight materials with improved stiffness, modulus, and strength. The significant feature of PMC’s is their reinforcement. The main role of the reinforcement is to withstand the load applied to the composite. However, in order to fulfill its purpose, the reinforcements must meet some basic criteria such as: being compatible with the matrix, making chemical or adhesion bonds with the matrix, having properties superior to the matrix, presenting the optimal orientation in composite and, also, having a suitable shape. The current review reveals a detailed study of the current progress of synthetic fibers in a variety of reinforced composites. The main properties, failure modes, and applications of composites based on synthetic fibers are detailed both according to the mentioned criteria and according to their types (organic or inorganic fibers). In addition, the choice of classifications, applications, and properties of synthetic fibers is largely based on their physical and mechanical characteristics, as well as on the synthesis process. Finally, some future research directions and challenges are highlighted.

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Shear strength of homopolymer and copolymer aramid fibers

Cited by 12 publications

References 62 publications

Flame‐Retardant Host–Guest Films for Efficient Thermal Management of Cryogenic Devices

Flame‐Retardant Host–Guest Films for Efficient Thermal Management of Cryogenic Devices

On the low reinforcing efficiency of carbon nanotubes in high-performance polymer fibres

A Review on Synthetic Fibers for Polymer Matrix Composites: Performance, Failure Modes and Applications

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