A survey is given on the various options to seal water ingress from strata and from concrete structures by injecting different types of resins showing the scope and limits of the individual grouts. The report covers methacrylates and polyurethane hydrogels, one and two component polyurethane resins as well as silicate isocyanate resins. The use of fast reacting two component polyurethane resins...

      In order to prepare polyurethane elastomers with acceptable physical properties and good biocompatibility, novel polyurethane networks were synthesized via curing reaction of epoxy-terminated polyurethane prepolymers (EUPs) with hexamethylene diamine. EUPs were prepared from reaction of glycidol with NCO-terminated polyurethanes (ITPs). ITPs were also synthesized from reaction of one equi...

Field robots are widely used to accomplish a variety of tasks in many different fields. However, setting of the locomotive ability of these robots at the design phase may prevent the traversal of unknown rough terrain. To address this shortcoming of existing robots, we designed a robot that is able to modify its environment by using polyurethane foam to construct auxiliary structures to facilit...

Novel reactive polyols were synthesized via modification of castor oil, a renewable agricultural raw material with epoxy resin and triethylamine as a catalyst. This polyol was used for synthesis of polyurethane coating. Coating formulations were developed by reacting polyol with aromatic adduct, aliphatic adduct and castor oil based adduct in different NCO/OH ratio. All coating composition syst...

The recent article by Luu et al. (1) predicting an excess lifetime risk from polyurethane covered breast implants of 1 in 400,000 is based upon numerous questionable assumptions and cannot go unchallenged. I have listed below several of the more obvious problems with this study and its conclusions. The estimated dose of polyurethane was too high. The authors use a weight of foam in their dosage...

A series of designed drug-release systems were prepared and established for clear moisture healing. These systems were designed to have an interpenetrating polymer network (IPN) structure, which contained a breathable polyurethane film, hydrocolloidlayer, and polyacrylate adhesive layer. Breathable polyurethane film (2000 g/m(2)/24 hr) with high moisture permeability was employed as a base for ...

in this work, a thermoplastic polyurethane elastomer (tpue) model based on polytetramethylene glycol, toluene diisocyanate and 1,4-butanediol was selected and synthesized. according to this model two types of polyurethane nanocomposites were prepared by in situ polymerization and melt intercalation procedures. the organo-modified nanoclay was used in nanocomposites samples in 0.4 weight percent...

PURPOSE: To assess the capsules formed by silicone implants coated with polyurethane foam and with a textured surface. METHODS: Sixty-four Wistar albinus rats were divided into two groups of 32 each using polyurethane foam and textured surface. The capsules around the implants were analyzed for 30, 50, 70 and 90 days. Were analyzed the following parameters: foreign body reaction, granulatio...

Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetramethylene glycol as the soft segments were electrospun from their solutions in N,N-dimethylformamid...

Purpose: Morphological study comparing castor oil polyurethane and autogenous bone graft to repair bone defect in zygomatic bone of rabbits. Methods: Twenty-four adult, male New Zealand rabbits were randomly distributed between two groups of twelve. Bone defects of 5mm in diameter were cut through the zygomatic bone and filled with polyurethane discs in the experimental group or autogenous bone...