Jan-Anders Edvin Maansson

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The integration of shear-thickening fluids (STFs) into composite structures has been investigated with the aim of tuning part stiffness and damping capacity under dynamic deformation. Results from oscillatory rheological measurements for a STF based on con ...

The damping properties of unidirectional, 0/90 and twill 2/2 flax fibre (FF) reinforced epoxy composites containing 40 vol% of fibres have been measured by vibration beam testing (VBT). The influence of the impregnation quality, the fibre/matrix adhesion, ...

The photo-curing behavior of composites containing nanosized SiO2 in an acrylated hyperbranched polymer matrix was investigated by means of photo differential scanning calorimetry. The chemical conversion data were analyzed using an autocatalytic model, pa ...

The parameters affecting the packing stress of fiber mats for melt impregnation, resin transfer molding and compression molding are systematically investigated. An analytical equation based on local bending of fibers, which was previously derived for non-impregnated networks, is applied to composite mats of dispersed planar bundles impregnated with molten polypropylene. It is shown that many simultaneous mechanisms interact during packing of impregnated bundle mats, in particular when the mats are needled.

Uniaxial fragmentation tests were carried out in situ in a scanning electron microscope (SEM) on 10-nm-thick silicon oxide coatings deposited by plasma enhanced chemical vapor deposition on poly(ethylene terephthalate). In order to prevent charging effects due to the isolating nature of the oxide surface, an additional conductive gold layer was sputtered onto the coating prior to its tensile loading in the SEM chamber. The gold layer was shown not to affect initiation of tensile failure of the oxide coating

Non-autoclave processing of honeycomb sandwich structures generally leads to poor compaction and high porosity of the skins, along with a decreased skin-core adhesion. The pressure level inside the honeycomb cells plays an important role and is controlled ...

Light-trapping textures were produced in hyperbranched polymer (HBP) silica nanocomposites using a UV-nanoimprint lithography (UVNIL) replication method, either in batch or roll-to-roll processes. The hardness of the HBP was found to increase by a factor o ...

This study has characterized the energetics of both the liquid state and the solid state of two commercially available epoxy resins: a DGEBA- and a TGMDA-based epoxy system. The surface properties of the liquid epoxies were evaluated by wetting measurements using a dynamic contact angle analysis (DCA). The Lifshitz-van der Waals components of the surface tension were found to be similar for both epoxy systems, while the acid-base components were found to be slightly different. Two different techniques were

A process window providing guidelines to minimize internal stress levels and to prevent void formation during cure of thermoset composite materials is presented. A model taking into account the applied pressure and the level of stress borne by the fiber assembly was introduced to calculate the hydrostatic internal stress state in the resin during cure. Based on the fundamental mechanisms of matrix shrinkage and evolution of viscoelastic properties under the given processing conditions, the internal stress i

Optical microscopy and transmission electron microscopy have been used to investigate the morphology of polylactide (PLA)/microfibrillated cellulose (MFC) composites prepared by: compression molding of wet-comingled MFC and PLA latex or powder, twin-screw ...

Structured silica woven fabrics have been derivatized with functional groups able to anchor by exchange of Fe3+-ions and TiO2 showing a stable performance during the visible light induced decoloration of the Orange II azo-dye. The kinetics and efficiency of the decoloration mediated by the catalytic loaded silica fabrics with Fe3+-ions were seen to be much higher than found with homogeneous Fenton reagents (Fe3+/H2O2) with the equivalent Fe3+ content. The same was observed for derivatized membranes where Ti

A novel method allowing rapid production of reliable composites with increased dielectric constant and high dielectric strength for dielectric elastomer actuators (DEA) is reported. The promising approach using composites of conductive particles and insula ...

Three methods to mix ceramic fillers, hydroxyapatite or β-tricalcium phosphate, with a polymer matrix, a poly l-lactic acid, are investigated as a first step prior to supercritical foaming to prepare porous composite structures for biomedical applications. ...

The feasibility of integrating thermoplastic isotactic polypropylene/ montmorillonite nanocomposite matrices into conventional fiber-reinforced composites has been investigated. Two basic processing routes were considered: long glass fiber (GF)-reinforced ...

Dry, compression molded films of medical grade poly-L-lactide (PLLA) showed a marked reduction in tensile strength and strain after accelerated ageing in aqueous NaOH at 50 degrees C. accompanied by mass loss, surface erosion, increased hydrophilicity and, ...

The influence of the surface morphology of semi-crystalline poly(ethylene terephthalate) (PET) and polyamide 12 (PA12) films on the adhesion and cohesion of thin oxide coatings is analysed, with attention paid to the role of spherulites and processing additives. The failure mechanisms of the coating are determined by means of fragmentation tests and the results are modelled using a constant interfacial strength approach with a Weibull-type probability of fracture. Coating failure is shown to be initiated at

Two forms of carbon fibre reinforced polyamide 12 (PA12) were compared during non-isothermal stamp forming. The first was a stretch broken commingled yarn woven into a fabric, studied at three initial preconsolidation levels. The second was produced by in ...

The present work focuses on the interfacial mechanical behaviour of a model composite consisting of a solid droplet on a fibre, generally referred to as the microbond test. The interfacial adhesion is derived from the modelling of stress transfer in the microbond geometry including process-induced internal stresses, following two alternative approaches, namely the numerical discretisation of the droplet profile, and the equivalent cylinder analytical solution. This is in contrast to previous approaches, whi

Crack patterns of 53 nm and 103 nm thick silicon oxide coatings on poly(ethylene terephthalate) films are analyzed under equibiaxial stress loading, by means of a bulging cell mounted under an optical microscope with stepwise pressurization of film specimens. The biaxial stress and strain are modeled from classical elastic membrane equations, and an excellent agreement is obtained with a finite element method. In the large pressure range, the derivation of the biaxial strain from force equilibrium considera

The glass transition behavior of hyperbranched polymer (HBP) molecules with suspensions of silica and glass particles up to the concentrated regime (25 vol %) was analyzed by modulated differential scanning calorimetry (MDSC). The reversing and nonreversing components of the MDSC signal were measured on suspensions of untreated and silylated particle of size in the nanometer and micrometer ranges. The heat capacity step (ΔCp) at the glass transition of the HBP was found to be independent of silica loading f

Jan-Anders Edvin Maansson

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Dynamic properties of sandwich structures with integrated shear-thickening fluids

The role of twist and crimp on the vibration behaviour of flax fibre composites

Conversion and shrinkage analysis of acrylated hyperbranched polymer nanocomposites

The packing stress of impregnated fiber mats

Mechanical analysis of ultrathin oxide coatings on polymer substrates in-situ in a scanning electron microscope

Vacuum-bag processing of sandwich structures: role of honeycomb pressure level on skin-core adhesion and skin quality

UV-nanoimprint lithography and large area roll-to-roll texturization with hyperbranched polymer nanocomposites for light-trapping applications

Characterization of epoxy resin surface energetics

A structure and property based process window for void free thermoset composites

Morphological investigation of polylactide/microfibrillated cellulose composites

Silylation and sulfonation of structured supported catalysts active in the decoloration of azo-dyes under visible light

High Breakdown Field Dielectric Elastomer Actuators Using Encapsulated Polyaniline as High Dielectric Constant Filler

Processing of homogeneous ceramic/polymer blends for bioresorbable composites

Hybrid glass fiber-reinforced thermoplastic nanocomposites

Accelerated ageing and degradation in poly-L-lactide/hydroxyapatite nanocomposites

Influence of substrate morphology on the cohesion and adhesion of thin PECVD oxide films on semi-crystalline polymers

Stamp forming of carbon fibre/PA12 composites - a comparison of a reactive impregnation process and a commingled yarn system

The influence of internal stresses on the microbond test 1 : Theoretical analysis

Biaxial fragmentation of thin silicon oxide coatings on poly(ethylene terephthalate)

Immobilized polymer fraction in hyperbranched polymer/silica nanocomposite suspensions