نتایج جستجو برای: polyurethane foams
تعداد نتایج: 10571 فیلتر نتایج به سال:
In this article, we study on the effect of different congregated granularities of microencapsulated n-octadecane on polyurethane foamed system, and the making of the polyurethane foams with high contents of microencapsulated n-octadecane. The results show that, when relative low granularities of microencapsulated phase change materials (MicroPCMs) are used as additives, the remnant water and fo...
Topical hemostatic agents can be used to treat problematic bleedings in patients who undergo surgery. Widely used are the collagen- and gelatin-based hemostats. This study aimed to develop a fully synthetic, biodegradable hemostatic agent to avoid exposure to animal antigens. In this in vitro study the suitability of different newly developed polyurethane-based foams as a hemostatic agent has b...
Tannin/furanic rigid foams were modi ed by either polymeric 4,4’ diphenylmethane diisocyanate (pMDI) or a one-component polyurethane still presenting reactive isocyanate groups (PUR). Several di erent sequences of mixing the isocyanate and polyurethane with the chemicals used to prepare tannin-based foams were tested. Scanning electron microscopy (SEM) showed that addition of either pMDI or PUR...
Amit Desai, Maria L. Auad, 1 Hongbin Shen and Steven R. Nutt* Gill Foundation Composites Center, Department of Chemical Engineering and Materials Science, University of Southern California, 3651 Watt Way VHE-602, Los Angeles, CA 90089-0241, USA * E-mail: [email protected] Abstract: Hybrid composite phenolic foams are reinforced with chopped glass and aramid fibers in varied proportions. The mechanic...
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...
Developed in last decade, the shape memory polymers (SMP) have been gaining widespread attention for new product innovation. They are lightweight, have a high strain/shape recovery ability, are easy to process, and required properties can be tailored for a variety of applications. Recently a number of medical applications have been considered and investigated for polyurethane-based SMP material...
Improvements in passenger compartment comfort continue to be one of the key needs of the global transportation industry. Since their introduction more than 40 years ago, flexible molded polyurethane foams have successfully contributed to the comfort provided by all forms of transportation seating. Initially required to provide just a wide range of load bearing, seating foams are now being desig...
Polyurethane shape memory polymer (SMP) foams are proposed for use as thrombogenic scaffolds to improve the treatment of vascular defects, such as cerebral aneurysms. However, gas blown SMP foams inherently have membranes between pores, which can limit their performance as embolic tissue scaffolds. Reticulation, or the removal of membranes between adjacent foam pores, is advantageous for improv...
UNLABELLED BACKGROUND Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or chemical pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment ...
Polyurethane foam (PUF) is an outstanding material for various applications, which is manufactured by propelling liquid isocyanate-polyol mixture to form foams in the presence of blowing agent. In order to reduce the ozone depletion and environmental pollution from organic blowing agents, waterblown PU foams were prepared with various water levels (311phr), and the effects of water level on mec...
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