Biobased Polyurethane Coatings with High Biomass Content: Tailored Properties by Lignin Selection

New biobased polyurethane (PU) coatings with high lignin content were developed and characterized in this work. These materials were based on a ?,?-diisocyanate monomer (1,4-bis(4-isocyanato-2-methoxyphenoxy)butane, VA-NCO) obtained from lignin-derived vanillic acid and its further cross-linking reaction with three different nonchemically...

Highly sensitive piezo particulate-polymer foam composites for robotic skin application

Tri-phase PZT-porous polyurethane (PU) composites are investigated with the aim of developing conformable, highly sensitive tactile sensors for application in Human-Machine Interactions. The main goal is to reduce the dielectric constant of the polymer matrix, and improve flexibility of traditional diphase piezo-composites, consisting of ceramic...

Compressive response of multiple-particles-polymer systems at various strain rates

Multiple-particles-polymer systems of a polyurethane elastomeric matrix embedding 25wt.% and 50wt.% 0.5 mm-diameter PMMA particles were investigated using a split Hopkinson pressure bar (SHPB) setup for revealing the dynamic compressive mechanical response. Taking the 25wt.%-particles-polymer system as a reference case, the characteristics of...

Glass interface effect on high-strain-rate tensile response of a soft polyurethane elastomeric polymer material

The glass interface effect on dynamic tensile response of a soft polyurethane elastomeric polymer material has been investigated by subjecting a glass-polymer system of this polymer material matrix embedded a single 3 mm-diameter glass particle to impact loading in a split Hopkinson tension bar (SHTB) setup. The characteristics of the dynamic...

Emission of volatiles from spray polyurethane foam (SPF) insulated crawl spaces

The emission of (di)isocyantes, polyols and blowing agents from curing Spray Polyurethane Foam (SPF) was studied in a house having its crawl space recently insulated. Before insulation a blank measurement was made and he emission was followed up to 144 hours after the insolation application. The emission of SPF emitting products and therefore...

Polyurethanes for potential use in transparent armour investigated using DSC and DMA

A material combination that may be applied as transparent armour is glass-clad polyurethane. These are comprised of a relatively thin glass strike face and a relatively thick (transparent) polyurethane backing layer. Three transparent polyurethane samples were investigated using differential scanning calorimetry (DSC) and dynamic mechanical...

Polyurethanes used in transparent armour investigated using DSC and DMA (Abstract)

Influence of synthetic packing materials on the gas dispersion and biodegradation kinetics in fungal air biofilters

The biodegradation of toluene was studied in two lab-scale air biofilters operated in parallel, packed respectively with perlite granules (PEG) and polyurethane foam cubes (PUC) and inoculated with the same toluene-degrading fungus. Differences on the material pore size, from micrometres in PEG to millimetres in PUC, were responsible for...

Application of porous foams for size-selective measurements of airborne wheat allergen

Background: Exposure to airborne wheat allergen is a well-known cause of bakers' allergy and asthma. Airborne wheat allergen can be measured by enzyme immunoassays (EIAs) in extracts of inhalable dust samples, but only limited knowledge is available on the size distribution of wheat allergen-carrying particles. Recently, a new sampling medium,...

Multiple linear regression analysis of bacterial deposition to polyurethane coatings after conditioning film formation in the marine environment

Many studies have shown relationships of substratum hydrophobicity, charge or roughness with bacterial adhesion, although bacterial adhesion is governed by interplay of different physico-chemical properties and multiple regression analysis would be more suitable to reveal mechanisms of bacterial adhesion. The formation of a conditioning film of...

Bacterial deposition to fluoridated and non-fluoridated polyurethane coatings with different elastic modulus and surface tension in a parallel plate and a stagnation point flow chamber

Deposition of three marine bacterial strains with different cell surface hydrophobicities from artificial seawater to polyurethane coatings on glass with different surface tensions and elastic modulus was studied in situ in a parallel plate (PP) and stagnation point (SP) flow chamber. Different surface tensions of the coatings were established...

Rheological behaviour of latexes in-can and during film drying

In-can rheology was studied for sixteen model acrylate latexes and a commercial vinyl/acrylate copolymer latex. Following the model of Quemada, the shear thinning behaviour, the effects of latex neutralisation and the copolymer composition could be described. Furthermore, the rheological effects of coalescing agents and thickeners (a cellulose...

Associative thickeners: Their adsorption behaviour onto latexes and the rheology of their solutions

The interaction between an associative thickeners in solution and an anionic surfactant has been studied with rheology and surface tension measurements. Both a HEUR thickener and low molecular weight HMHEC thickener interacted strongly with the surfactant. The addition of surfactant leads in both cases to a reinforced transient network at low...

Medium optimization for nuclease P1 production by Penicillium citrinum in solid-state fermentation using polyurethane foam as inert carrier

A solid-state fermentation system, using polyurethane foam as an inert carrier, was used for the production of nuclease P1 by Penicillium citrinum. Optimization of nuclease P1 production was carried out using a synthetic liquid medium. After a two-step medium optimization using a fractional factorial experimental design, nuclease P1 productivity...

Reduction of the radon entry rate from building materials by industrial surface coatings

The retaining effect of over 20 different surface coatings on the free 222Rn exhalation rate has been studied. Coatings that are normally applied for decoration of walls and ceilings in homes were found to be ineffective. Reductions of up to 75% were found for other coatings studied, when applied to all sides of the test walls. If the surface...

Pain, thermal sensation and cooling rates of hands while touching cold materials

Hand cooling and resulting comfort and pain were studied in 12 subjects, while touching six different materials (polyurethane foam, wood, nylon, rustproof steel, aluminium, and temperature-controlled metal) which were initially at ambient temperature. This was done for three ambient temperatures (-10°, 0° and 10°C), after pre-exposure exercise...

Simulation of hand cooling due to touching cold materials

A simple analytical model has been developed to simulate the cooling of the hands due to touching various types of cold material. The model consisted of a slab of tissue, covered on both sides with skin. The only active mechanism was the skin blood flow. The blood flow was controlled by body core temperature, mean skin temperature, and local...