Polycarbonate aesthetic properties

First, polycarbonate offers a broad palette of physical, mechanical, and aesthetic properties, allowing it to serve many different types of apphcations requiring quite different properties. Its performance profile offers... 

Acrylic Resins. The first synthetic polymer denture material, used throughout much of the 20th century, was based on the discovery of vulcanised mbber in 1839. Other polymers explored for denture and other dental uses have included ceUuloid, phenolformaldehyde resins, and vinyl chloride copolymers. Polystyrene, polycarbonates, polyurethanes, and acryHc resins have also been used for dental polymers. Because of the unique combination of properties, eg, aesthetics and ease of fabrication, acryHc resins based on methyl methacrylate and its polymer and/or copolymers have received the most attention since their introduction in 1937. However, deficiencies include excessive polymerization shrinkage and poor abrasion resistance. Polymers used in dental appHcation should have minimal dimensional changes during and subsequent to polymerization exceUent chemical, physical, and color stabiHty processabiHty and biocompatibiHty and the abiHty to blend with contiguous tissues. 

Polycarbonates are used in optics, transparent technical parts, aesthetic applications and protection devices for their transparency, mechanical properties, impact resistance, rigidity, good creep behaviour, fatigue resistance, insulating properties, dimensional stability, low moisture uptake, broad range of service temperatures (-100°C up to -i-135°C),food contact and sterilization possibilities for suitable grades. 

The following TPs are the main thermoforming materials processed high-impact and high-heat PS, HDPE, PP, PVC, ABS, CPET, PET, and PMMA. Other plastics of lesser usage are transparent styrene-butadiene block copolymers, acrylics, polycarbonates, cellulosics, thermoplastic elastomers (TPE), and ethylene-propylene thermoplastic vulcanizates. Coextruded structures of up to seven layers include barriers of EVAL, Saran, or nylon, with polyolefins, and/or styreneics for functional properties and decorative aesthetics at reasonable costs.239-241... 

Optical properties of polymers are characterized by haze, transparency, and gloss (Villalobos et al., 2005). Transparency increases the aesthetic value of the packaging and is usually desirable as it helps in the identification of the packaged material. However, there are light sensitive products, which do not require transparency to have a longer shelf life. Hence, the level of transparency varies from product to product. Some of transparent packaging plastics are PET, PS, and polycarbonate (PC). 

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