Novel method of healing the fibre reinforced thermoplastic composite: A potential model for offshore applications

Abstract

Continuous fibre reinforced thermoplastic composites are increasingly finding their use as engineering materials in many industries due to the excellent fire, smoke and toxicity performance. However, the composite component produced using automated continuous fibre reinforced thermoplastic tapes laying machine are susceptible to sudden failure emanating from microscale cracks. This study demonstrates the healing potential of a layered Glass Fibre Reinforced Polymer (GFRP) composite consisting of alternative layers of GFRP and a magnetic polyamide-6 (PA-6) nanocomposite (PNC) film. The self-healing process is presented in three steps, viz. (i) polymer nanocomposite synthesis, (ii) preparation of the layered GFRP layered composite sample and (iii) selfhealing and testing of GFRP layered composite sample. Firstly, the multilayer dog bone sample consisting of a magnetic polymer nanocomposite (PNC) film sandwiched between thermoplastic unidirectional GFRP tapes are prepared. Healing is triggered by exposing the damaged multilayer sample to microwave causing selective heating of nanocomposite film and its subsequent melting. The healing process completes when liquid polymer fills the micro-crack in the multilayer tape through capillary action and solidifies upon cooling. The healing yields 84% of the undamaged tensile strength recovery. Results demonstrate the potential application of an autonomous self-healing method for thermoplastic composite used in the offshore environment.

A Review of Sensing Technologies for Non-Destructive Evaluation of Structural Composite Materials

“…The emitted ultrasonic signal travels within the Though FMCW has recently been applied as a stand-alone system for NDE of WT blades for studying the delamination, cracks, and water ingress [35,37], the literature shows that there is a wide area of applications for FMCW-based NDE of composites. Due to its nature of interaction with dielectric materials, it can also be used to identify variable materials present in a composite material [151], and the concept can even be extended for a micron-level nanoparticle agglomeration study, which is a critical aspect in bespoke polymer nanocomposites [152][153][154]. However, similar to other methods, it also has some limitations, which include a limited depth of penetration against other methods involving ground penetrating radar, X-ray, Gamma, and neutron [155], in addition to spatial resolution, which is limited by the bandwidth and low power, which limits the penetration depth in the target composite [18,35,36,155].…”

Optimising Crystallisation during Rapid Prototyping of Fe3O4-PA6 Polymer Nanocomposite Component

“…Dispersing magnetic nanoparticles into the semi-crystalline thermoplastic PA6 (Polyamide 6) is useful for preparing a polymer nanocomposite (PMC) capable of selfhealing a composite component by induced stimuli. The matrix of PA6 is versatile for engineering applications due to its ability to rapidly polymerise and provide good mouldability as well as mechanical properties [1][2][3][4][5]. PMCs with different functionalities or multifunctionalities can be produced using different types of nanoparticles (NPs) (Figure 1); however, the uniform dispersion of NPs is a precondition to achieve the required functionality.…”

“…PMCs with different functionalities or multifunctionalities can be produced using different types of nanoparticles (NPs) (Figure 1); however, the uniform dispersion of NPs is a precondition to achieve the required functionality. Previously, many nanoparticle dispersion techniques, such as melt blending, solution blending, high-shear mixing and in situ polymerisation, have been used [3][4][5][6][7][8]. However, the in situ PMC manufacturing method is most favoured for preparing PA6 PMC, as it provides the ease of mixing the nanoparticles in a low-viscosity ε-caprolactam monomer before the activator/catalyst-mediated polymerisation [9] is carried out, ensuring effective dispersion.…”

“…However, the in situ PMC manufacturing method is most favoured for preparing PA6 PMC, as it provides the ease of mixing the nanoparticles in a low-viscosity ε-caprolactam monomer before the activator/catalyst-mediated polymerisation [9] is carried out, ensuring effective dispersion. The incorporation of magnetic nanoparticles (MNPs), such as Fe 3 O 4 , using in situ methods has been proven to be useful in achieving melting through the magnetocaloric effect; however, its inclusion modifies the degree of crystallinity and resulting properties of the magnetic PA6 polymer [3]. Due to interface adhesion and MNPs dispersion, the degree of crystallinity and the crystalline structure within the polymer are affected [3,4], which, in turn, affects the multifunctional properties of the synthesised polymer magnetic PMC [1,[10][11][12].…”

Self-healing polymer–clay hybrids by facile complexation of a waterborne polymer with a clay

“…According to the healing mechanism, self-healing polymers are classified into autonomous and nonautonomous systems in which the damages are healed without and with the assistance of external stimuli, respectively. Such external stimuli as microwave irradiation, 10,11 UV-Visible irradiation, 12,13 heat, 14,15 magnetic field, 16 pH, 17 and addition of organic solvents 18 have been used for healing. These stimuli require energy consumption, addition of active chemical reagents and chemical modification of polymer chains.…”