Stabilizers transparency

The demand of PET for packaging applications is growing fast. This fact is based on the outstanding and versatile properties of PET, such as tensile strength, toughness, dimensional stability, transparency and chemical resistance. The need... 

Crystalline with good mechanical properties, high impact strength, good thermal and oxidative stability, transparent, selfextinguishing, low moisture absorption Good heat resistance, dimensional stability, resistance to cold flow, solvent, dielectric properties... 

Polycarbonate (PC) is the fourth largest volume material. It is an amorphous engineering thermoplastic with good thermal stability, transparency, impact resistance and the ability to be processed on conventional machinery. Its surface properties are important for many applications, including medical, optics and so on. Table 2.10 illustrates the properties of PC. 

Fluid handling excellent dimensional stability, transparent, solvent-and hydrolysis-resistant, with high burst strength... 

Polycarbonate possesses high mechanical strength, high thermal stability, transparency, good dielectric properties, thanks to which it is finding wide use in various branches of industry. It was shown in [22] that the thermal decomposition of polycarbonate, analogous to certain polyarylates, begins at temperatures above 400°C and is accompanied... 

Outstanding properties UV stability, transparency, good electrical properties ... 

At the end of this chapter it is necessary to recall that antistatic agents affect some of the properties of polymers, such as heat stability, structural stability, transparency, stress rupture resistance, surface aspect, ease of welding, stamping, and metallization. 

Figure 5.48 Weathering behavior of polycarbonate (white non-stabilized, brown non-stabilized, transparent UV-stabilized) [672]...

The combination of excellent stability, transparency and large nlo properties make these materials attractive competitors to both PA and PDAs. Several other families of benzazoles are known and are suitable for nlo study PQL [124], POL [125], BBL and BBB [126] (Fig. 4.20). Efforts to prepare block copolymers and the introduction of spacer groups in both the main chains are being made to allow different orientation and processing [126]. 

Biaxial orientation is widely utilized because excellent balances of properties, such as high tensile strength, dimensional stability, transparency, and electrical properties, are provided. The amorphous web of SPS can be biaxially oriented... 

Microemulsions have been attracting considerable attention due to properties such as ease of formation, thermodynamic stability, transparency and high solubilization capacity. Microemulsions are excellent delivery systems for nutraceuticals (Rozner et al., 2007,2008) and as vehicles for chemical reactions, such as acid autocatalysis (Mcllwaine et al, 2008). They have also been used for the separation and purification of proteins, metal extraction and as drug delivery systems (Hatton, 1989 Pileni, 1989 Garti et al, 2006 Spemath and Aserin, 2006 Kogan et al, 2007). 

To avoid the negative properties of PDMS and variations of PDMS, researchers have investigated the use of fluoropolymers as mold materials in soft lithography. Fluoropolymer elastomeric moltb have lowered surface energies, tunable modulus, chemical stability, transparency to visible light, and solvent resistance. Rolland et have developed photocurable... 

Solution vehicles consist of water soluble polymers not manufactured by emulsion polymerization. The solution vehicle is an alkali soluble polymer in aqueous solution or a blend of polymers with combined properties into a single waterborne varnish. Soluble polymers are made by free radical polymerization in a processing solvent or as addition or condensation products with heat reaching temperatures up to 265 °C. Solution vehicles are mixtures of soluble resins unlike emulsion polymers. A solution vehicle is used to increase adhesion to film and improve ink printabihty or transfer to meet specific performance requirements. The solution vehicle provides pigment dispersion stabilization, transparency, low film forming temperature, gloss and re-solubility. An alkali soluble resin is a carboxylic acid functional polymer neutralized (solubilized) with ammonia, amine or sodium hydroxide. The add numbers are generally above 100. Ammonia or volatile amines are used in most aqueous inks except for news print inks. After evaporation of the amine, the resin becomes insoluble and resistant to water spray or other water contact. The ink is re-solubilized with alkaline water for the clean-up cycle. For news print ink, the polymers are solubiHzed with sodium hydroxide to maintain re-solubility (open time) of the ink on the press. News print ink pressman prefer unlimited open time and fewer clean-up cycles. Water resistance is not required since ink penetrates the news print paper fibers. 

Imaging plates are exposed similar to radiographic films. They are read out by a LASER-scanner to a digital image without any developing process. After optical erasing of the virtual picture the same IP can be used cyclic up to more than 1000 times. The life time is limited by the mechanical stability of the IP s. An IP consists of a flexible polymer carrier which is coated with the sensitive layer. This layer is covered with a thin transparent protective foil. 

A beautiful and elegant example of the intricacies of surface science is the formation of transparent, thermodynamically stable microemulsions. Discovered about 50 years ago by Winsor [76] and characterized by Schulman [77, 78], microemulsions display a variety of useful and interesting properties that have generated much interest in the past decade. Early formulations, still under study today, involve the use of a long-chain alcohol as a cosurfactant to stabilize oil droplets 10-50 nm in diameter. Although transparent to the naked eye, microemulsions are readily characterized by a variety of scattering, microscopic, and spectroscopic techniques, described below. 

SAN resins are rigid, hard, transparent thermoplastics which process easily and have good dimensional stability—a combination of properties unique in transparent polymers. 

Poly(vinyl chloride). To be converted into film, poly(viayl chloride) [9002-86-22] (PVC) must be modified with heat stabilizers and plasticizers, which increase costs. Plasticized PVC film is highly transparent and soft, with a very high gas-permeation rate. Water-vapor transmission rate is relatively low. At present, PVC film is produced by blown-film extmsion, although casting and calendering are employed for heavier gauges (see Vinyl POLYAffiRS). 

Dehydration or Chemical Stabilization. The removal of surface silanol (Si—OH) bonds from the pore network results in a chemically stable ultraporous soHd (step F, Fig. 1). Porous gel—siHca made in this manner by method 3 is optically transparent, having both interconnected porosity and sufficient strength to be used as unique optical components when impregnated with optically active polymers, such as fiuors, wavelength shifters, dyes, or nonlinear polymers (3,23). 

Since acetal resins are degraded by ultra violet light, additives may be included to improve the resistance of the polymer. Carbon black is effective but as in the case of polyethylene it must be well dispersed in the polymer. The finer the particle size the better the ultra violet stability of the polymer but the poorer the heat stability. About 1.5% is generally recommended. For white compounds and those with pastel colours titanium dioxide is as good in polyacetals as most transparent ultraviolet absorbers, such as the benzophenone derivatives and other materials discussed in Chapter 7. Such ultraviolet absorbers may be used for compounds that are neither black, white nor pastel shade in colour. 

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