Lexan properties

Polycarbonates are an unusual and extremely useful class of polymers. The vast majority of polycarbonates are based on bisphenol A [80-05-7] (BPA) and sold under the trade names Lexan (GE), Makrolon (Bayer), CaUbre (Dow), and Panlite (Idemitsu). BPA polycarbonates [25037-45-0] having glass-transition temperatures in the range of 145—155°C, are widely regarded for optical clarity and exceptional impact resistance and ductiUty at room temperature and below. Other properties, such as modulus, dielectric strength, or tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respective glass-transition temperatures, T. Whereas below their Ts most amorphous polymers are stiff and britde, polycarbonates retain their ductiUty. 

Property ASTM method Lexan 101 Medon 8320"- Lexan 470l "- ... 

Uses The electrical and electronics industries are the largest users. It is used also in blender housings, kitchen utensils and babies milk bottles. The physical properties are improved by stretching to form crystalline polymers like "Lexan". 

Much the most important polycarbonate in commercial terms is made from 2,2-di(4-hydroxyphenyl)propane, commonly known as bisphenol A. This polymer was discovered and developed by Farbenfabriken Bayer [92], The synthesis and properties of this and many other polycarbonates were described by Schnell in 1956 [93], The polymer became available in Germany in 1959, and was given the trade name Makrolon by Bayer (in the USA, Merlon from Mobay). General Electric (GE) independently developed a melt polymerisation route based on transesterification of a bisphenol with DPC [94], Their product, Lexan, entered the US market in 1960. The solution polymerisation route using phosgene has since been displaced by an interfacial polymerisation. 

Property Lexan 141 Lexan 3414a ASTM method... 

Property ASTM method Lexan 101b Merlon 8320C>d Lexan 470Y ... 

Table II. Mechanical Property Comparisons 20% Toly sulfonate Lexan Polysulfone...

Physical Property Shell 5A64 Homo PP Dow 8354N HD PE Huntsman 3037 HIPS Zytel 1016 Nylon 6 Lexan 141 PC Rohm Haas V920 Acrylic Dow Magnum 342EZ ABS... 

The mechanical properties of a craze were first investigated by Kambour who measured the stress-strain curves of crazes in polycarbonate (Lexan, M = 35000) which had first been grown across the whole cross-section of the specimen in a liquid environment and subsequently dried. Figure 25 gives examples of the stress-strain curves of the craze determined after the 1st and 5th tensile loading cycle and in comparison the tensile behavior of the normal polymer. The craze becomes more and more elastic in character with increasing load cycles and its behavior has been characterized as similar to that of an opencell polymer foam. When completely elastic behavior is observed the apparent craze modulus is 25 % that of the normal poly-... 

Synthetic polymers have many useful properties. The strength of one kind of polymer called Lexan is so great that it is used to make bullet-proof windows. 

Property ASTM Units ABS/PC Cycoloy EHA Sable Bayblend T65 Bayer Pulse 710 Styron PC Lexan 141 Sabic... 

TypicsJ properties [98, 99] Units (Test method) Lexan 101 resin Lexan PPC4501 resin Lexan PPC4701 resin Makrolon APEC DP9- 9331 resin Makrolon APEC DP9-9371 resin... 

By using this concept, resorcinol poly(ester carbonate)s were developed and introduced under the trade name Lexan SLX grades. The block copolymers of Iso- and Terephthalate esters of iJesorcinol (ITR) and BPA polycarbonate can be prepared by melt, solution, or interfacial reactions [191], The properties of these resins are controlled by adjusting the percentage of resorcinol phthalate to BPA carbonate (Fig. 14.18). 

Data obtained from the Lexan Polycarbonate Resin Property Guide, GE Advanced Materials. 

P. D. Sybert, S. Kiel, D. Rosendale, J. Di, and D. Shen, Weatherability and Physical Properties of Opaque Injection Moldable Lexan SLX Resins, SPE ANTEC, 2523 (2005). 

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