Producing closed-cell foams is generally cheaper and simpler than open-cell foams. However, the acoustic efficiency of closed-cell foam materials is poor because it is very difficult for the acoustic waves to penetrate the material. A method to remove the membranes closing the cell pores (known as reticulations) and thus to improve the acoustic behavior of closed-cell foam material is presented...

A new sensitive and low cost method for cadmium determination at microg l(-1) levels that combines an on-line preconcentration system with the thermospray flame furnace atomic absorption spectrometry technique (TS-FF-AAS) is described in this work. Cadmium is preconcentrated from an acidic medium (pH 2.0) by forming a complex with ammonium O,O-diethyldithiophosphate (DDTP), which is then adsorb...

Flame retardant (FR) chemicals have often been added to polyurethane foam to meet required state and federal flammability standards. However, some FRs (e.g., PBDEs and TDCIPP) are associated with health hazards and are now restricted from use in some regions. In addition, California's residential furniture flammability standard (TB-117) has undergone significant amendments over the past few yea...

Two modified passive samplers were evaluated at multiple field locations. The sampling rate (SR) of the modified polyurethane foam (PUF)-disk passive sampler for total gaseous mercury (TGM) using gold-coated quartz fiber filters (GcQFF) and gaseous oxidized mercury (GOM) using ion-exchange membranes (IEM) were 6.4 ± 1.4 and 15.3 ± 0.3 m(3) day(-1), respectively. The relative percent difference ...

With the phase-out of PentaBDE in 2004, alternative flame retardants are being used in polyurethane foam to meet flammability standards. However, insufficient information is available on the identity of the flame retardants currently in use. Baby products containing polyurethane foam must meet California state furniture flammability standards, which likely affects the use of flame retardants in...

We model electromagnetic interrogation of a polyurethane foam using the TE mode of the 2D Maxwell’s equations reduced to the wave equation for a fixed frequency in the THz regime. The foam block target contains knit lines which are modeled by modifying the speed of propagation, i.e., by altering the index of refraction. We describe our efforts to estimate the dielectric constant in the knit lin...

The fluid and cellular phases of inflammatory resonse have been measured using a technique employing subcutaneous implantation of polyurethane foam cubes impregnated with heat-killed Mycobacterium tuberculosis. Phenylbutazone, azathioprine, aspirin, cyclophosphamide, and prednisolone suppressed fluid response, whereas sodium aurothiomalate, hydroxychloroquine, and D-penicillamine had no effect....

Methylene chloride and CFCs are used as auxiliary blowing agents in the manufacture of flexible polyurethanefoams and are promptly emitted during the manufacturing processes.The concentrationof the auxiliary blowing agent are quite low due to the accepted practice of using large volumes of air to lower the ambient concentration of toxic isocyanates (a key chemical in the urethane reaction seque...

Polyurethane foam functionalized with β-naphthol was prepared by covalently linking the reagent with the polyurethane foam matrix through –N=N– groups. The reagent-bonded polyurethane foam (β-Nap-PUF) was characterized by use of elemental analysis, UV–visible and IR spectroscopy, thermal analysis (TGA), density, and stability. β-Nap-PUF was found to be very suitable for preconcentration and det...

Transesterification of palm olein with glycerol can increase the functionality by introducing additional hydroxyl groups to the triglyceride structure, an advantage compared to using palm olein directly as feedstock for producing palm-based polyol. The objective of this study was to synthesize transesterified palm olein-based polyol via a three-step reaction: (1) transesterification of palm ole...