Lexan Poly

Usually poly (bisphenol - A carbonate, commercially - lexan) is used as a polymer matrix. 

Thermoplastic multilayer laminate composed from an outer layer of resorcinol arylate poly(ester)s, a middle layer comprising a polycarbonate), e.g., LEXAN 131, and an inner-tie layer made from ASA or ABS have been described (37). Resorcinol arylate poly(es-ter)s may be understood as an isophthalic terephthalic resorcinol bisphenol A copolymer. 

Sinclair-Koppers Co. Lexan 125 bisphenol A polycarbonate from General Electric Co. Polysulfone aromatic poly(sulfone-ether) from Union Carbide Corp. and PPO poly(2,6-dimethyl-p-phenylene oxide) from General Electric Co. 

And so we arrive at the basis for the strength of many polymers, especially plastics—molecular entanglement Picture hitting a glass windowpane with a hammer. The same blow to an equivalently shaped piece of Lexan (polycarbonate) or Ludte poly[methyl methacrylate]), both transparent plastics, does not break the polymer. In fact, the plastic glass is somewhat resilient, causing the hammer to bounce off of it. 

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-... 

In the fall of 1966, researchers at North Star Research Institute began a search for compression-resistant microporous substrates.19 This effort resulted in the development of microporous sheets of polycarbonate (Lexan) and poly-sulfone (Udel).20 Figure 5.4 shows a graph comparing the flux levels and flux stability for three membranes made at that time (a) float-cast cellulose acetate on microporous polysulfone, (b) float-cast cellulose acetate on a mixed cellulose ester microfilter support and (c) a standard asymmetric cellulose acetate membrane. The improvement in membrane fluxes was readily apparent, when switching from cellulosic substrates to the microporous polysulfone substrate. 

Carbonic acid is a diacid with suitable diols, it can form polyesters. For example, when phosgene (the acid chloride of carbonic acid) reacts with a diol, the product is a poly(carbonate ester). The following equation shows the synthesis of Lexan polycarbonate a strong, clear, and colorless material that is used for bulletproof windows and crash helmets. The diol used to make Lexan is a phenol called bisphenolA, a common intermediate in polyester and polyurethane synthesis. 

Lexan XT Poly(carbonate-co-silicone) copolymer GE Plastics... 

Medical grades are supplied with other engineering plastics such as Radel poly(phenylene sulfone) and Lexan polycarbonate. 

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). 

Dainton, F. S., Evans, D. M., Hoare, F. E., Melia, T. P. Thermodynamic functions of linear high polymers. Polymer 3 (196 Part I Polyoxymethylene. p. 263 Part II Thermodynamic functions of penton, p. 271 Part III Polyethylene. p. 277 Part IV Stereospecific poly-a-olefiiies. p. 286 Part V cis-and trans-l,4-polybntadiene. p. 297 Part VI Polysulphones. p. 310 Part VII Lexan. p. 316 Part VIII Methylmethacrylate and polymethylmeth acr3date. p. 317. 

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