Jan-Anders Edvin Maansson

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Nanocomposite materials based on a HBP and silica are produced using either a dual-cure sol/gel and photopolymerization process or by mixing silica nanoparticles with the HBP. In both cases the conversion of the HBP is independent of composition and obeys ...

Driven by the need for more cost-effective applications, researchers and design engineers of polymer composites are facing increasing demands for the development of faster and more environment-friendly processing methods. Rapid processing techniques require a better understanding and a more efficient control of phenomena such as heating, impregnation, bonding and solidification. Most of the new techniques promote non-isothermal and transient phenomena in order to achieve faster transformation of the materia

In many cases of composite processing by liquid matrix impregnation, the fiber reinforcement is compressed when it comes in contact with the liquid and then relaxes as the matrix flows within its pores. This phenomenon can be analyzed in terms of local fluid flow, mass conservation and mechanical equilibrium. A model is proposed to simulate the kinetics of impregnation, and the evolution of the fiber volume fraction profile as the resin front progresses, as well as after the front has reached the end of the

A new quantitative thermodynamic model for the prediction of phase equilibrium behaviour of thermoset-reactive modifier polymer blends has been developed. The model combines the Flory Huggins lattice theory with a group contribution theory for the prediction of the thermodynamics evolution. The model predicts the free energy of mixing as a function of blend composition, temperature, and degree of polymerisation. The evolution during polymerisation of both the entropy and enthalpy of mixing has been taken in

During cure of epoxy resins, polymerization induces an increase in mechanical properties, which is accompanied by a volumetric shrinkage. When the resin is cured in a constrained mold to which it adheres, tensile stresses will hence develop, which may exceed the strength of the resin at a given curing stage. Voids will then form. The origin and governing parameters of void formation are studied using an epoxy resin cured in a three-dimensionally constrained glass mold following isothermal cure cycles. Two t

The different steps associated with the curing of a PVAc/polyester blend are identified and correlated to the mechanism of shrinkage control in the presence of a low-profile additive (LPA). Poly(vinyl acetate) (PVAc) is used as a LPA and is shown to induce ...

We review the process rates and energy intensities of various additive processing technologies and focus on recent progress in improving these metrics for laser powder bed fusion processing of metals, and filament and pellet extrusion processing of polymer ...

The cohesive and adhesive properties, and related critical radius of curvature of thin multilayer insulator coatings on a 152 μm thick flexible steel substrate were investigated using tensile experiments carried out in-situ in an optical microscope. This m ...

An experimental method based on a falling pressure measurement is proposed to evaluate the through thickness air permeability of prepregs during cure, with two set-up variants. One concerns the measurement of the inherent air permeability and the other app ...

The curing reaction of an epoxy resin [diglycidyl ether of bisphenol A (DGEBA)] combined with a methyl-hexahydrophtalic anhydride (MHHPA) hardener and a benzyldimethylamine (BDMA) accelerator was studied over a temperature range of 60 140°C to build its isothermal time-temperature-transformation (TTT) cure diagram. This includes gelation and vitrification measurements using rheological measurement techniques, monitoring of the glass transition temperature and the reaction kinetics by differential scanning c

The cost-effective production of high-performance and durable steel reinforced thermoplastic composites requires improvement of the adhesion encountered at the interface between metallic substrates (galvanized steel) and a thermoplastic elastomer (TPU). Combined requirements of processing speed, adhesion and durability were assessed by using cationic photo-polymerized coatings at the TPU-metal interface. The adhesion was studied by pull-out tests on co-molded TPU matrix - galvanized steel wires samples befo

We report the first measurements of a self-healing polymer that combines a microencapsulated liquid healing agent and shape memory alloy (SMA) wires. When a propagating crack ruptures the embedded microcapsules, the liquid healing agent is automatically re ...

In the impregnation process, when pressure is applied, the dry fiber preform is first compressed and then unloads as the matrix flows within the pores. It has been shown earlier that for glass mat-reinforced thermoplastic (GMT) materials, the time to provi ...

The present paper discusses the uniqueflow behavior in a new type of extruder. The extruder design is based on a hollow conical assembly of static (stators) and rotating (rotor) parts. Extrusion is achieved from each side of the rotor to provide a two-layer annular product. Flow is helicoidal in the vicinity of the rotor tip and die entry where the polymer layers merge. However, it becomes fully parallel to the main extrusion direction after a certain distance downstream from the rotor tip. Numerical simula

A waterborne latex-based technique, in which functionalized laponite is attached to PS and acrylic latex particles, is used to prepare films containing up to 50 wt% laponite. At high laponite contents this leads to a cellular arrangement of the laponite-rich layers, concentrated at the latex particle interfaces. MDSC shows that a significant proportion of the organic matrix does not contribute to the glass transition. However, this "rigid" matrix fraction arises from intercalation of the laponite stacks, an

Damage occurring under tensile loading and the resulting increase of electrical resistance of indium-doped tin oxide and amorphous graphite coatings on various polymer substrates are investigated, using an electro-fragmentation method in situ in an optical ...

Desorption processes of low-molecular-weight compounds from the surface of smectites into the gas phase determine a number of processes, e.g. those involved in drug delivery and the release of herbicides. The desorption has not been investigated thoroughly ...

The development of internal stress during cure of epoxy and hyperbranched polymer- modified epoxy resins was characterized, taking into account the evolving viscoelastic properties, the volumetric shrinkage due to the chemical reaction, and the thermal expansion. A criterion for void formation during cure in a constrained mold was proposed, providing guidelines for the construction of a process window for manufacturing of void-free composites. It was shown that the internal stress development in epoxy resin

A study of the microstructure developing at the surface of glass fibers in a poly(vinyl acetate) (PVAc)/polyester blend is presented. Three different experimental methods are used: a technique based on the Wilhelmy method to measure the wettability of the ...

Different types of inorganic oxide films composed of a chemical composition gradient single layer were designed, fabricated and characterized. Compositionally graded thin films were created by power-controlled co-sputtering of alumina (Al2O3) and silica (S ...

Jan-Anders Edvin Maansson

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Low-Stress Hyperbranched Polymer/Silica Nanostructures Produced by UV Curing, Sol/Gel Processing and Nanoimprint Lithography

Material phenomena controlling rapid processing of thermoplastic composites

Impregnation of compressible fiber mats with a thermoplastic resin, Part I: Theory

A thermodynamic model for thermoset polymer blends with reactive modifiers

Stress-initiated void formation during cure of a three-dimensionally constrained thermoset resin

Low-Profile mechanisms in a PVAc/polyester blend

Note on the Rate and Energy Efficiency Limits for Additive Manufacturing

Mechanical integrity analysis of multilayer insulator coatings on flexible steel substrates

Through thickness air permeability of prepregs during cure

TTT - Cure diagram of an anhydride-cured epoxy system including gelation, vitrification, curing kinetics model and monitoring of the glass transition temperature

Fast-curing coatings for adhesion promotion between metallic oxides and thermoplastic polyurethane

Performance of self-healing epoxy with microencapsulated healing agent and shape memory alloy wires

Graded glass mat reinforced polypropylene

Modeling and Analysis of Helicoidal Flow in a Conical Extruder

Small strain mechanical properties of latex-based nanocomposite films

Electrofragmentation modeling of conductive coatings on polymer substrates

Kinetics Of Desorption Of Water, Ethanol, Ethyl Acetate, And Toluene From A Montmorillonite

Internal Stress Control in Epoxy Resins and their Composites by Material and Process Tailoring

Phase separation at the fiber-matrix interface in composites based on a thermoplastic/polyester blend

Design and fabrication of compositionally graded inorganic oxide thin films: Mechanical, optical and permeation characteristics