Flexible sheeting

In principle, mesoscale methods can provide a means for connecting one type of simulation to another. For example, a molecular simulation can be used to describe a lipid. One can then derive the parameters for a lipid-lipid potential. These parameters can then be used in a simulation that combines lipids to form a membrane, which, in turn, can be used to compute parameters describing a membrane as a flexible sheet. Such parameters could be used for a simulation with many cells in order to obtain parameters that describe an organ, which could be used for a whole-body biological simulation. Each step, in theory, could be modeled in a different way using parameters derived not from experiment but from a more low-level form of simulation. This situation has not yet been realized, but it is representative of one trend in computational technique development. 

Uses. Phthabc anhydride is used mainly in plasticizers, unsaturated polyesters, and alkyd resins (qv). PhthaUc plasticizers consume 54% of the phthahc anhydride in the United States (33). The plasticizers (qv) are used mainly with poly(vinyl chloride) to produce flexible sheet such as wallpaper and upholstery fabric from normally rigid polymers. The plasticizers are of two types diesters of the same monohydric alcohol such as dibutyl phthalate, or mixed esters of two monohydric alcohols. The largest-volume plasticizer is di(2-ethylhexyl) phthalate [117-81-7] which is known commercially as dioctyl phthalate (DOP) and is the base to which other plasticizers are compared. The important phthahc acid esters and thek physical properties are Hsted in Table 12. The demand for phthahc acid in plasticizers is naturally tied to the growth of the flexible poly(vinyl chloride) market which is large and has been growing steadily. 

In addition to aerospace uses, sihca fibers can be twisted into sewing threads and yams for weaving into fabrics. These fabrics are used extensively for heat-resistant clothing, flame curtains for furnace openings, thermocouple protection, and electrical insulation. The cloth can also be used to encapsulate other fibers to produce flexible sheets. 

One reason for the success of PVC is its formulation versatility. Products range from rigid piping and window frames to soft flexible foams, with such diverse materials as vinyl leathercloth, flexible sheeting and playballs somewhere in between. 

Produced from PVC compounds containing plasticizers such as dioctyl phthalate, this is a flexible sheeting suitable for lining tanks made from steel and concrete. The maximum temperature at which this lining can be used is 60°C. 

Permeability to Heater Vapour of Flexible Sheet Materials, BS 3 177 1959, British Standards Institution, London... 

Monomers- + Flexible -sheet ribbons Rigid fibrils and fibers Nematic Nematic ... 

Graphite is offered moreover in flexible sheets (e.g. Sigraflex of the SGL-Carbon Group). This is primarily a sealing material, but it is suitable also as electrode or corrosion resistant current feeder (erosion in case of gas evolution is possible). 

After the composite has been manufactured onto its mould, an anti-adherent flexible sheet is applied onto it, and then a light vacuum is created by a suitable system (see Figure 5.24). 

New possibilities exist for the development of piezoelectric devices using so-called 1-3 composites. These consist of an array of piezoelectric pillars embedded in a pliable material providing a transducer in the form of a flexible sheet (Fig. 7.5) which can be moulded to fit the shape of a reactor. A particular advantage of such a system is that the emitting face is a combination of ceramic and plastic and can provide much better acoustic transmission into aqueous systems. 

Whether offered as flexible sheeting or as a rigid material, such as in shed construction, always seek an alternative to PVC for use in the garden. PVC contains dioxin, a persistent organic pollutant (POP) that accumulates in the food chain and can be released during manufacture and disposal. 

A formed laminate is made by relative movement of first and second contoured mould surfaces toward each other to compress a flexible sheet and vertically spaced film with a foamable liquid mixture therebetween that has substantially completed expansion but not yet substantially cured so as to form the flexible sheet and provide a collapsed foam layer bonded to the sheet. The flexible sheet is preferably porous cloth, vinyl or leather. A film which is preferably a nonadherent plastic such as PE is preferably positioned in a vertically spaced relationship with the flexible sheet either above or below the sheet with the foamable liquid mixture received therebetween for the expansion prior to the compression that provides the formed laminate. The formed laminate... 

FIGURE 6.2 A film of polyacetylene forms on the inner surface of the reaction vessel, after ethyne gas passes over the catalyst solution of the walls. The paper-thin flexible sheet of polyacetylene is then stripped from the walls before doping. (Photograph by James Kilkelly. Originally published in Scientific American)... 

In India, flexible sheet explosives are generally made from indigenously available unsaturated polyester resins, epoxy resins and natural rubber etc. and common... 

One of the representatives of this group of explosives, EL-506 A, consists of PETN combined with plasticizers to form flexible sheets of 10x20 in., fabricated in a number of thicknesses [68]. 

A quantity of I (0.200 g, 0.412 mmol) is dissolved in 20 mL of acetone in a 100-mL Schlenk flask in the air. After 48 h at room temperature in the air, the deep purple color of the solution fades to a pale brown with precipitation of a crystalline material. The reaction is complete when a TLC (IB2-F flexible sheets, J. T. Baker, CH2C12 as elutant) shows the disappearance of the band due to I (R = 0.3) and the appearance of the band due to II (Rr = 0). The reaction mixture is dried under vacuum. The solid product is washed with 5 mL of diethyl ether and 20 mL of hexane and dried again to give shining black crystals. The total weight of crystals is 0.171 g (0.0541 mmol), corresponding a 96% yield based on total cobalt when optimized. The checkers observed variable and generally lower yields. 

Detosheet Flexible Sheet Explosives. Detasheet is a high explosive developed and manufd by the DuPont Co. Composed of integral mixrure of PETN and elastomeric binder, Detasheet is flexible over a wide range of temps, easy to cut and handle, yet, retains most of the expl props of PETN alone. In addition, it is safe to use and is completely water-... 

Sheet Explosives. See under Detasheet Flexible Sheet Explosives in Vol 3, D99-L to D101-L, and Flexible Explosives in Vol 6, F107-L... 

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