Alternating copolycarbonates

FAB-MS has been used to identify the low molar mass oligomers produced in the partial ammonolysis of an essentially alternating copolycarbonate containing resorcinol and bisphenol-A (BPA) units. ... 

Vitalini, D., Mineo, R, Di Bella, S., Fragala L, Maravigm, R, and Scamporrino, E., Synthesis and Matrix-Assisted Laser Desorption Ionization-Time of Flight Characterization of an Exactly Alternating Copolycarbonate and Two Random Copolyefhers Containing Schiff Base Copper(It) Complex Nonlinear Optical Units in the Main Chain, Macromolecules, 29, 4478, 1996. 

Yokoe M., Aoi K., Okada M., Biodegradable polymers based on renewable resources. Vll. Novel random and alternating copolycarbonates from l,4 3,6-dianhydrohexitols and aliphatic diols, J. Polym. ScL Part A Polym. Chem., 41,2003,2312-2321. Yokoe M., Aoi K., Okada M., Biodegradable polymers based on renewable resources. Vlll. Environmental and enzymatic degradabihty of copolycarbonates containing l,4 3,6-dianhydrohexitols, J. App. Polym. ScL, 98, 2005,1679-1687. 

Block copolymers comprising carbonate and arylene ether blocks have been prepared by the catalytic decarboxylation of random or alternating copolycarbonates. This novel route to block copolymers is catalyzed by a number of catalysts and requires only that one of the bisphenols in the starting copolycarbonates be activated by electron-withdrawing substituents, e.g. 4,4 -dihydroxydiphenyl sulfone (bisphenol S), or 4,4 -dihydroxybenzophenone (bisphcnol K). 

The random copolycarbonates were prepared by the standard phosgenation procedure in dichloromethane with pyridine as the acid acceptor. Because of the slight difference in reactivity, these polymers may have a very small degree of blockiness which should not affect the results of this work. The alternating copolycarbonates were prepared in a similar fashion except that bisphenol A was first converted to the bis-chloroformate before the addition of bisphenol S or bisphenol K. All polymers were capped with tert-butylphenol. This work was conducted on 1 1 copolycarbonates of bisphenol A with either bisphenol S or bisphenol K. The chemistry of this novel procedure is illustrated in Scheme 1. 

Syntheses.—The syntheses of several new polycarbonates have been described, for example based on 4,4 dihydroxy-o (i -dimethylbenzalazine. This polymer has been characterized by DSC thermal analysis and X-ray diffraction. The synthesis and characterization of some copolycarbonates of 2,2-bis(4-hydroxyphenyl)-propane and 1,1,1-trichloro 2,2-bis(4-hydroxyphenyl)ethane has also been described. The thermal mechanical properties of alternating copolymers produced... 

Despite the wide range of the PEGs used as segments for the alternating copolymers, only copolycarbonate prepared from PEG 4000 was completely water soluble. The use of the hydrophilic PEG 4000 segment was intended to render the polymer water soluble. 

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