Polycarbonates polyarylates

The polymerization of cyclic low-molar-mass polycarbonates, polyarylates, and PBT to high-molar-mass thermoplastics has been extensively studied by the General Electric Company during the last decade.57,58 Due to very low viscosity, cyclic oligoesters can be processed like thermosetting resins but retain thermoplastic properties in the final state, after polymerization in the presence of suitable... 

Zoller, P., "A Study of the Pressure-Volume-Temperature Relationships of Four Related Amorphous Polymers Polycarbonate, Polyarylate, Phenoxy, and Polysulfone," J. Polym. Sci., Polym. Phys. Ed., 20, 1453 (1982). 

To further investigate the question of polymer structure-permeability relationships, this study reports oxygen permeability measurements on a group of structurally varied bisphenol based polymers. In addition to representing commercially important classes of engineering thermoplastics, polycarbonates, polyarylates and polyetherimides can be easily prepared from a common set of... 

PPE/HIPS blends filled the price-performance gap between the styrenic resins (HIPS, ABS) and the engineering resins such as polycarbonate, polyarylate and polysulfones. The technology and applications of PPE/HIPS blends have already been discussed under the styrenic resin blends section (Table 15.3). 

This Figure notes that combinations of amorphous (high T ) engineering polymers (e.g., PPE, polycarbonate, polyarylate) with lower T crystalline polymers (e.g., polyamide-66, polybutyleneterephthalate), offers the modulus-temperature behavior desired for the noted application. 

Some ordered structure is formed in the surface layer adjoining the friction surface during friction of polyheteroarylenes of the chain and cyclochain structure (polycarbonate, polyarylates, pol3dmides, pol3rphenylquinoxalines, polybenzimidazoles and others). This results in stabilization of friction and reduction of the friction coefficient [107]. 

S.L. Bourke, J. Kohn, Polymers derived from the amino acid 1-tyrosine polycarbonates, polyarylates and copolymers with poly(ethylene glycol), Adv. Drug Deliv. Rev. 55 (2003) 447-466. 

Since the early discovery of miscibility between the low-cost polystyrene and PPE, several commercial grades of PPE/HIPS have been developed, which offer a wide choice of heat resistance (DTUL), impact strength, and melt processability (Cizek 1969 Fried et al. 1978). This versatility of PPE/HIPS blends led to their unparalleled commercial success, accounting for nearly 50 % of market volume of all engineering polymers commercial blends. PPE/HIPS blends filled the price-performance gap between the styrenic resins (HIPS, ABS) and the engineering resins such as polycarbonate, polyarylate, and polysulfones. The technology of PPE/HIPS blends has already been discussed previously under the styrenic blends section (Sect. 19.3), and the typical blend properties are shown in Tables 19.6 and 19.32. 

In dew of the nonprocessibility of conventional poly(L-tyrosine), which cannot be used as an engineering plastic, variational derivatives were emlsioned. The development of tyuosine-based polycarbonates, polyarylates and polyiminocarbonates represents the first time tyrosine-derived polymers wth favorable engineering properties have been identified. 

Thus, the kinetics of the oxidation of the overwhelming majority of pol5miers is described by S-shaped curves, as is the case, for example, in the thermooxidative destruction of polyolefins, polyethylene oxide, polyamides, polycarbonates, polyarylates, epoxide resins, rubbers, etc. 

Polypropylene Polyformaldehyde Aliphatic polyamides Epoxide resin hardened ethylenepolyamine Epoxide resin hardened anhydride Polycarbonate Polyarylates TD and ID... 

This is especially important for such polymers as polycarbonate, polyarylates, and other polymers that can be reprocessed at high temperatures, in which the oxidation processes develop at a considerable rate. 

Important polymers that are produced by polyaddition are polyamide 6 (nylon) and all kinds of polyurethanes. In polycondensation one mol of a small molecule (typically H2O) is liberated per step of chain growths, important polymers that are produced by polycondensation are polyamide 6.6, poly(ethylene terephthalate) (PET), polycarbonate, polyarylate, and polysulfide. Step growth polymerization is usually slow, equilibrium limited and isothermal to slightly exothermic. Polyaddition and polycondensation reactions of monomers with three or more reactive end groups lead to three-dimensionally crosslinked resins. 

Shogenov, V. N., Kozlov, G. V, Gazaev, M.A., Shustov, G. B., Mikitaev,A. K. (1985). The Correlation Strength-Notch Length in Polycarbonate-Polyarylate Blend Fihns. sokomolek. Soed. B, 27(4), 244-245. 

Compared to polycarbonate, polyarylates often exhibit better gloss behavior, less deposit formation, and better transparency. Moreover, the mechanical properties of polyarylates are less impaired than those of polycarbonate [83]. Coating with polyarylate is often recommended in order to protect polycarbonate against UV degradation [572]. 

An example of the use of extractor-type PlMRs in reactions other than esterification is the gas-phase decomposition of MTBE catalysed by tung-stophosphoric acid. Lee et reported the use of closed-loop recycle membrane reactors by using polycarbonate, polyarylate or cellulose acetate membranes to selectively permeate the formed methanol in a flat membrane reactor configuration, with the catalyst packed in the retentate side and by using helium as sweep gas in the permeate side. The authors also used a tube-and-shell reactor configuration with the catalyst packed in the shell side being the sweep gas fed to the tube side. 

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