Polyurethane consolidation

Adhesive-Coated Material. The addition of an adhesive-coated material [335] to proppants decreases the flowback of the particulates. Such adhesive-coated materials can be inorganic or organic fibers, flakes, and the like. The adhesive-coated material interacts mechanically with the proppant particles to prevent the flowback of particulates to the wellbore. The consolidation of a proppant also may occur via a polyurethane coating, which will slowly polymerize after the fracturing treatment because of a polyaddition process [1856]. 

R. Wiser-Halladay. Polyurethane quasi prepolymer for proppant consolidation. Patent US 4920192, 1990. 

Bayer consolidated its American holdings at about the same time as BASF. But, given its history, it focused on a somewhat different set of product lines, especially pharmaceuticals. In 1977, partly from antitrust pressure, Bayer acquired Monsanto s 50 percent in Mobay, the joint venture that had expanded its line to polyurethane and agricultural chemicals. Bayer s primary drive, however, continued to be in pharmaceuticals. In the same year, it also purchased Cutter Laboratories, makers of nutrients and ethical drugs. Soon thereafter. Cutter recorded its first profit. Bayer s success in turning around... 

Thermoplastics in the form of a lacquer have poorer mechanical strength than the thermosetting resins but are more easily removed, should this prove necessary. Polyvinyl acetate and polyurethane are good examples of this class of consolidants, particularly on wrought iron artefacts. Many of the copper and copper-based alloys, such as bronzes and brasses recovered from the Mary Rose, were consolidated with a solution of acrylic resin dissolved in toluene (Incralac). 

Ceflthane. [Flexible Prods.] One- and two-comprment polyurethane coatings for elastomers, encapsulation, consolidation, structural enhancement of media. 

Though numerous types of plastics materials are presently used for automotive applications, future vehicles will probably use fewer resin variables. This consolidation trend is well underway and is a result of postconsumer recycling requirements (see Ghapter 6), which increasingly emphasize the use of only a few families of materials. Auto manufacturers will rely primarily on four key resin families for their plastics applications polyolefins, polyamides, polyurethanes, and styrenics. The future use of PVC for automotive applications is uncertain due to pressure of environmental groups who assert that the resin contaminates automotive shredder residue with chlorine. 

Polyurethane board can include a low density foam block for applications from styling models to cutter path verification, and styling. Low density master models from which vacuum-consolidated RP tools and components can be produced. 

In 2000, we have begun our research on this topic paying particular attention to the possibility of finding new chemical systems able to frontally polymerize and new FP applications. Specifically, we have studied polyurethanes (19, 20), polyester tyrene resins (21), polydicylopentadiene (22) and its BPNs with polyacrylates (23), Furthermore, we were able to prepare films (24) and to apply FP to the consolidation of porous materials (i.e. stones, woods, flaxes, papers), in particular -but not only- those having a historical-artistic interest (24), In this chapter we present a brief overview of these recent findings. 

A dry fiber preform is used with the layers of fibers/fabric holding it together with a powder binder. This initial preform is consolidated under heat and pressure to form a rigid preform, which is then placed in the blade mold and a core of low density polyurethane foamed in situ, followed by applying layers of carbon fiber at 45° using a braiding machine. 

Reputedly the tallest mast (53.33 m) in sailing history was fabricated in two halves by the Consolidated Yacht company for the Zeus super yacht, using carbon/epoxy prepreg, vacuum bagged and cured in a special oven tailormade from foil insulated polyurethane... 

In-situ intercalative polymerization of layered silicates is perhaps the best example of reactive molding of nanocomposites today. In-situ interactive polymerization of layered silicates, which was discussed above, can be achieved either with thermosetting matrices, such as polyurethane and epoxy, or with thermoplastic systems, such as nylon-6 [4, 23]. A general requirement for reactive molding of nanocomposites is that the particulate phase of a PNC is compatible with the monomer phase of the reactive molding system, which acts as a polymerizable solvent This makes it possible to achieve and maintain a fine dispersion of the particulate phase in the monomer during matrix consolidation, resulting in excellent particle distribution in the final PNC. Above, it was noted that the hydroxylated surface of cellulose makes it reactive to isocyanate. Cellulose whiskers may therefore represent the ideal particulate phase for a nano-RIM process. For this to be achieved, the whisker-polyurethane system needs to be better characterized, so that the RIM process can be adapted to fabrication of cellulose whisker PNCs. 

This objective is being achieved by the use of many different materials and processes. As ever with plastics, the main theme is consolidation of components. For interior panels, this takes the form of integrating two or more layers in a sandwich construction. Examples include a textile skin formed over wood-filled polypropylene pressing, in a single operation, to produce a door panel, and a unit seat, in which the polyurethane foam is formed with the fabric facing already in position. 

Puterman M., Jansen B., Kober H. Development of organosiUcone-polyurethanes as stone preservation and consolidation materials. J. Appl. Polym. Sci. 1996 59(8) 1237-1242 RothM. Conservation of natural stone monuments. Praxis derNaturwissenschaften, Chemie, 1988 37(8) 6-11... 

For example, Li et al. [153] used a simple solution-precipitation technique to improve the dispersion of CNTs in a polycarbonate solution by sonication at a frequency of 20 kHz for 10 min. They showed that the CNTs were uniformly dispersed in polycarbonate matrix on its consolidation. Safadi et al. [154] dispersed MWNTs in PS using ultrasonication and dismembrator at 300 W for 30 min. Uniform dispersions of CNTs in PS were achieved by using sonication. Recently, Cho and coworkers successfully prepared polyurethane (PU)/MWNT composites with better dispersion of CNTs up to 20 wt% in PU [155]. 

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