Anisotropic polymer foams have been prepared, which exhibit a Poisson's ratio exceeding 1, and ratios of longitudinal to transverse stiffness exceeding 50. The foams are as much as 20 times stiffer in the longitudinal direction than the foams from which they were derived. The transformation process involved applying a uniaxial stress sufficient to produce 25% to 45% axial strain to open-cell po...

An extensive product range is mandatory to be a key player in the pipe insulation market. The polyurethane preinsulated pipe producers are responding to global opportunities by diversifying their activities into industrial, marine, oil and gas applications. Moreover, the requirements for traditional district heating preinsulated pipes including initial thermal conductivity and its ageing perfor...

A dry starch–oil composite was blended with each of three glycols; ethylene, polyethylene, and propylene, and then reacted with isocyanate to produce polyurethane foams. The liquid glycols permitted the dry composite to blend well with the other ingredients in the foam formulations. Infrared spectra confirmed the presence of urethane structures in the composite–glycol foams. Polyethylene glycol...

Thermal and photo initiated release of tris(1-chloro-2-propyl) phosphate (TCPP) from different polyurethane foam materials were studied using a validated GC-MS method with a linear range of 0.34-680 g/ml. The release of TCPP from two foam types was reported and was found to follow first order kinetics with rate constants directly related to the ageing conditions and radiation intensity. Rate c...

Indoor residential pesticide applications present the potential for human exposures, particularly for small children. Personal contact with target and nontarget surfaces can result in transfer of pesticides to the skin, but the magnitude of such transfer is uncertain. This research compared surface sampling techniques [wipe and polyurethane foam (PUF) roller] with the removal ability of human s...

A fast and sensitive on-line procedure for the determination of zinc in water and biological samples was developed. Zinc was preconcentrated in a mini-column packed with polyurethane foam (PUF) chemically modified with zincon via -N=N- bonding. The optimal conditions for preconcentration were pH 8.5 and sample flow rate of 4.0 mL min(-1). Quantitative desorption of Zn(II) was obtained by 0.1 mo...

Lignosulfonate and lignosulfonate hydrolyzed under alkaline conditions were used as the polyol components in polyurethane foam formulations. Although the treatment increased hydroxyl group abundance, it did not improve the applicability of hydrolyzed lignosulfonate in polyurethane foam. Thus, the use of original lignosulfonate yielded foams of thermal stability and mechanical properties compara...

The objective of this matched case-control study was to determine whether women with Même or Replicon polyurethane-covered silicone breast implants are exposed to clinically significant levels of free 2,4-TDA from biodegradation of the polyurethane foam. Urine and serum samples were obtained from 61 patients with Même or Replicon breast implants and 61 controls on two separate occasions separat...

polyurethane foams are extensively used in different applications such as furnitures and sandwich structures due to better mechanical properties, higher acoustic and damping behavior, higher resistance to hydrocarbon, and aging.with respect to flammability of polyurethane materials and safety precaution in living and working environments there is a vital need to study and investigate published ...

We studied the seated buttock pressure distribution in six paraplegic patients by means of computerized pressure mapping. They were all male and their age ranged from 18 to 48 years old. Their level of paralysis varied from Th5 to L1. Five kinds of wheelchair cushions were studied: an air cushion, a contour cushion, a polyurethane foam cushion, a Cubicushion (which is made of polyurethane foams...