Strain localization in open-cell polyurethane foams: Experiments and theoretical model

Measurement and Modeling of Creep in Open-Cell NiAl Foams

Nickel-rich NiAl foams, consisting of open cells with hollow struts and exhibiting two relative densities (5.0 and 6.6 pct) and average cell sizes (1.27 and 0.85 mm), were creep tested between 800 °C and 1100 °C under compressive stresses between 0.10 and 1.50 MPa. For stresses lower than 0.50 MPa, the foams exhibit secondary creep with power-law behavior characterized by creep exponents and ac...

The Modification of Polyurethane Foams Using New Boroorganic Polyols (II) Polyurethane Foams from Boron-Modified Hydroxypropyl Urea Derivatives

The work focuses on research related to determination of application possibility of new, ecofriendly boroorganic polyols in rigid polyurethane foams production. Polyols were obtained from hydroxypropyl urea derivatives esterified with boric acid and propylene carbonate. The influence of esterification type on properties of polyols and next on polyurethane foams properties was determined. Nitrog...

Elimination of Amine Emissions from Polyurethane Foams: Challenges and Opportunities

Polyurethanes are a unique class of plastic in the sense that independent manufacturers buy liquid polyols and isocyanates and then react them in the presence of catalysts, surfactants and other additives in widely varying processing schemes to make the final commercial product. In some manufacturing scenarios, there is a growing concern about worker exposure to volatile organic chemicals (VOC)...

Effects of silicon surfactant in rigid polyurethane foams

The rigid polyurethane foams (RPUFs) have been fabricated from high functional crude 4,4’-di-phenylmethane diisocyanate (CMDI) and polypropylene glycols (PPGs) for a wide range of surfactant concentration with an environmently friendly blowing agent (HFC 365mfc). Cream time, gel time, and tack-free time increased with the addition of surfactant. Foam density decreased rapidly to a minimum at 0....

Do amines induce occupational asthma in workers manufacturing polyurethane foams?