An investigation into the relaxation response of a self-healing dual network polymer through controlled introduction of strain damage

Self-healing ability in polymers is typically probed by monitoring restorative properties after localized macroscopic damage or repetitive cycles of destructive testing followed by a healing cycle (e.g. cut-and-heal tests). However, the restoration of homogeneously distributed damage before ultimate failure remains largely unattended in...

Modelling self-healing magnetic textures in hydrodynamic bearings

Hydrodynamic bearings can be used to minimise friction, and their load capacity can be improved by texturing the bearing surfaces. However, due to mechanical contact between the surfaces during start and stop, these textures are susceptible to wear. Previously, a new method of creating textures using magnetorheological fluids as lubricant was...

Effect of diisocyanate mixtures on the healing of thermoplastic polyurethanes

Self-healing materials and, in particular, polymers are characterized by their ability to partially or fully restore their original properties or functions after damage. Amongst the healable polymer classes, thermoplastic polyurethanes have received increasing attention in the last years. This is mainly due to their broad application areas, the...

Additive manufacturing of a self-healing thermoplastic polyurethane

Additive manufacturing of smart polymers is a rapidly growing field. Additive manufacturing presents a versatile, low-waste manufacturing method for functional materials. Self-healing polymers are a type of smart polymers that are able to mend damage, either by the incorporation of an encapsulated healing agent or by intrinsic polymer design....

On the use of Laser Speckle Imaging to study local polymer dynamics

Development of a fracture fatigue test for lifetime quantification of footwear outsoles: a preliminary application to self-healing polymers

Previous research showed fracture failure in the outsole of sports footwear. There was no method available for the quantification of the material behavior in with this failure mechanism. Therefor the goal of this research was to develop a mechanical test method for quantification of fatigue fracture behavior of a material when a crack is present...

Mechanical testing and quantification of crack healing in self-healing yttria-stabilized zirconia thermal barrier coating

Thermal barrier coatings (TBC) are often applied to hot components of modern turbojet engines. These coatings increase the performance of the engine and enhance the lifetime of its structural components. Thus, improving the TBC lifetime is related with a reduction of maintenance costs and increased reliability. As an alternative to conventional...

On the in situ encapsulation of MoSi2B healing particles in YSZ TBCs: Self-healing of thermal barrier coatings (TBCs)

A novel method to encapsulate MoSi2B healing particles was explored via in situ shell formation in yttria-stabilised zirconia thermal barrier coatings (YSZ-BCs). The shell formation was analysed for MoSi2B healing particles alloyed with 2, 6 and 12 wt% Al. According to oxidation kinetics study at 1100˚C using thermogravimetry, MoSi2B-12 wt% Al...

Synthesis and oxidation behaviour of Ta-Al-C MAX phases

MAX-phase materials, a class of ternary carbides and nitrides that combine favorable properties of metals (conductivity and toughness) and ceramics (high temperature strength) have been shown to autonomously heal micro-cracks by high temperature oxidation. The investigation of Ta and Al containing MAX phases (Ta2AlC & Ta4AlC3) could render self...

Coating of MoSi2 healing particles for self-healing thermal barrier coatings

To increase lifetime of the protective thermal barrier coatings (TBC) in jet engines and other gas turbines, a self-healing approach based on MoSi2 healing particle addition is considered. However, due to rapid oxygen transport in yttria-stabilized zirconia (YSZ), a common TBC material, premature oxidation is a major problem. This thesis...

Kinetics of self-healing reaction in TBC with MoSi2 based sacrificial particles

A fundamental study on mechanical & physical properties of polymer-modified self-healing mortars using bacteria

A polymer-modified self-healing mortar is a mixture of Portland cement, water, sand, polymer and self-healing material. The polyacrylic ester emulsion (PAE) is used as polymer and as self-healing material bacterial spores from genus Bacillus + calcium lactate is used. The reason why this type of bacteria is used as a component of self-healing...