Glass elastomer

Identification of the materials of construction (i.e., plastics, paper, metal, glass, elastomers, coatings, adhesives, and other such materials) should be identified by a specific product designation (code name and/or code number) and the source (name of the manufacturer) alternate materials of construction should be indicated postconsumer recycled plastic should not be used in the manufacture of a primary packaging component, and if it is used for a secondary or associated component, then the safety and compatibility of the material for its intended use should be addressed appropriately... 

Ultimate storage has to be carried according to the specific sensitivities of the products (at room temperature, +4°C, -20°C). Again uncontrolled exposures to water vapor, oxygen (air), light, excess heat, or nonsterile environment are major factors to be considered. This obviously includes the composition and quality of the container itself, i.e., glass, elastomers of the stoppers, plastic or organic membranes. 

Substrate, Film (a) Glass, polymer (b) Polymer, polymer (C) Glass, elastomer (d) Glass, glass... 

At the First Symposium in 1977, the literature in this field could be encompassed in a single volume. Today, that is no longer possible. The field of Polymeric Liquid Crystals grew, and continues to grow, at a very rapid pace. At present, we know of every major mesophase in its polymeric form and of polymeric glasses, elastomers and fluids in their liquid crystalline form. Every year, new polymeric mesophases are being discovered. 

For a wide range of materials the emission of electrons (EE), positive ions (PIE), neutral species (NE), and photons (phE) has been observed accompanying fracture. We refer collectively to these emissions as fracto-emission. In this paper we review our work on fracto-emission where the fracture event involves interfacial or adhesive failure. The interfaces to be discussed include the following brittle materials/epoxy, glass/elastomers, and brittle materials/pressure sensitive adhesives. 

Both the pi-tensile and bar and rod tensile tests can be modified to test materials which are not easily fabricated into adherends. These materials may be glasses, elastomers, or thin films. The test specimens are prepared by forming a sandwich of the particular material, for example, as shown in Figure 4. The main consideration in this test is that the adhesion between the adhesive and sample ends must be greater than that between the adhesive... 

FIGURE 9.25. Deposition of drops at a glass/elastomer interface by (a) injection (water) or (b) dewetting (PFAS). A film (1) squeezed between a rubber marble and glass thins down (2) and dewets (3). Note the dimple formed during drainage (2) ... 

Microfluidic devices have been fabricated from a wide range of materials, such as silicon, fused silica, borosilicate glass, elastomers (poly(dimethylsiloxane)... 

Casting resin Thermoplastic elastomer Cast resin, flexible Mineral- and/or glass-filled Epoxy molding and encapsulating compound Polystyrene... 

Specialty coatings Specialty elastomers Specialty epoxy resins Specialty glass Specialty malts... 

Additional information on elastomer and SAN microstmcture is provided by C-nmr analysis (100). Rubber particle composition may be inferred from glass-transition data provided by thermal or mechanochemical analysis. Rubber particle morphology as obtained by transmission or scanning electron microscopy (101) is indicative of the ABS manufacturing process (77). (See Figs. 1 and 2.)... 

Elastomeric Modified Adhesives. The major characteristic of the resins discussed above is that after cure, or after polymerization, they are extremely brittie. Thus, the utility of unmodified common resins as stmctural adhesives would be very limited. Eor highly cross-linked resin systems to be usehil stmctural adhesives, they have to be modified to ensure fracture resistance. Modification can be effected by the addition of an elastomer which is soluble within the cross-linked resin. Modification of a cross-linked resin in this fashion generally decreases the glass-transition temperature but increases the resin dexibiUty, and thus increases the fracture resistance of the cured adhesive. Recendy, stmctural adhesives have been modified by elastomers which are soluble within the uncured stmctural adhesive, but then phase separate during the cure to form a two-phase system. The matrix properties are mosdy retained the glass-transition temperature is only moderately affected by the presence of the elastomer, yet the fracture resistance is substantially improved. 

Polymer systems have been classified according to glass-transition temperature (T), melting poiat (T ), and polymer molecular weight (12) as elastomers, plastics, and fibers. Fillers play an important role as reinforcement for elastomers. They are used extensively ia all subclasses of plastics, ie, geaeral-purpose, specialty, and engineering plastics (qv). Fillets are not, however, a significant factor ia fibers (qv). 

Properties. One of the characteristic properties of the polyphosphazene backbone is high chain dexibility which allows mobility of the chains even at quite low temperatures. Glass-transition temperatures down to —105° C are known with some alkoxy substituents. Symmetrically substituted alkoxy and aryloxy polymers often exhibit melting transitions if the substituents allow packing of the chains, but mixed-substituent polymers are amorphous. Thus the mixed substitution pattern is deUberately used for the synthesis of various phosphazene elastomers. On the other hand, as with many other flexible-chain polymers, glass-transition temperatures above 100°C can be obtained with bulky substituents on the phosphazene backbone. 

Plasma processing technologies ate used for surface treatments and coatings for plastics, elastomers, glasses, metals, ceramics, etc. Such treatments provide better wear characteristics, thermal stability, color, controlled electrical properties, lubricity, abrasion resistance, barrier properties, adhesion promotion, wettability, blood compatibility, and controlled light transmissivity. 

Polypropylene sheet has been used most extensively however, thermoplastic polyester, polycarbonate, and nylon versions are available (see Elastomers, synthetic Polycarbonates). Continuous strand glass fiber mat is the typical reinforcement. The limited number of sheet suppHers reduces potential for competitive pricing. 

The melt temperature of a polyurethane is important for processibiUty. Melting should occur well below the decomposition temperature. Below the glass-transition temperature the molecular motion is frozen, and the material is only able to undergo small-scale elastic deformations. For amorphous polyurethane elastomers, the T of the soft segment is ca —50 to —60 " C, whereas for the amorphous hard segment, T is in the 20—100°C range. The T and T of the mote common macrodiols used in the manufacture of TPU are Hsted in Table 2. 

Fig. 3. Elastomer properties as a function of monomer composition, butyl acrylate (BA), ethyl acrylate (FA), and methoxyethyl acrylate (MEA). (a), (—) glass-transition temperature (------------) swelling in ASTM No. 3 oil (b) (-) residual elongation at break, %, after heat aging.

FZ Characterization. FZ elastomer is a translucent pale brown gum with a glass-transition temperature, T of —68 to —72 C. The gum can... 

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