Synthesis and characterization of polycarbonates based on bisphenol S by melt transesterification

Abstract

Several sulfone‐containing polycarbonates, having inherent viscosity 0.25–0.30 dL g−1 in N,N‐dimethylformamide (DMF), were prepared by melt polycondensation of diphenyl carbonate (DPC) with various aromatic and aliphatic diols, in the presence of zinc acetate as transesterification catalyst. The polycarbonates were examined with IR spectra, inherent viscosity, solubility, tensile strength, contact angle, DSC and TGA. Almost all polymers were soluble in DMF, pyridine, N‐methyl pyrrolidinone (NMP), THF, phenol and dimethylsulfoxide (DMSO), partially soluble in nitrobenzene, but insoluble in acetone. Polycarbonate with introduced ether linkages leads to enhanced flexibility and elongation strength. The contact angle of the polycarbonate based on bisphenol S was found in the range 42–80°, smaller than that of polycarbonates based on bisphenol AF and bisphenol A. The wettability of polycarbonate films based on bisphenol S remarkably increased with increasing oxyethylene unit in polymer chain. The smaller values of Td of PC‐3‐PC‐7 than of PC‐1 is attributed to the flexible ether linkage. The thermal stability of a brominated aromatic polycarbonate (PC‐2) is less than that of the unbrominated one (PC‐1). The brominated aromatic polycarbonate (PC‐2) has good flame retardency, as indicated by the large limiting oxygen index 56. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2453–2460, 1997

Synthesis and Characterization of Polycarbonates by Melt Phase Interchange Reactions of Alkylene and Arylene Diacetates with Alkylene and Arylene Diphenyl Dicarbonates

“…Strong absorption bands due to the C–O–C stretching frequency for all polycarbonates were observed in the range from 1,161 to 1,254 cm -1 (Figure 2 and Table 3). These IR data are in accordance with the literature [22,23,32,33,42,43,44] and, therefore, confirm the formation of the various polycarbonates in this work. It was, however, observed that the C=O stretching vibration of aliphatic-aliphatic polycarbonate (1,743 cm -1 ) was very close to that of CHDM diacetate (1,741 cm -1 ).…”

Ab Initio Studies of Thermal Syn-Elimination Reactions in Carbonates: Effect of Structure on Reactivity

“…Their general characteristics are in line with previous studies. ,− All E i transition states for syn-elimination consist of a characteristic six-membered ring, which is typical for the concerted transfer of a proton and the simultaneous cleavage of the oxygen−α carbon bond. In conformance with the literature, it is also found here that the process is not fully concerted. This aspect can be studied in detail by comparing the relative lengthening of the two cleavage bonds in the transition state with respect to the reactant.…”

“…Up to now, the effect of a specific structural design of the polymer on the thermal degradation route was mostly obtained from experiment by measuring the thermal degradation temperature. This temperature is typically related to the polymer structure and can be measured by thermogravimetrical analysis (TGA) provided that the degradation products are sufficiently volatile . In this case, the degradation temperature is an indication for the reaction rates.…”

Ab Initio and Experimental Study on Thermally Degradable Polycarbonates: The Effect of Substituents on the Reaction Rates

“…Each polymer is characterized by its specific degradation temperature, defined as the temperature that is typically required to achieve thermal decomposition in good yield. The thermal properties of several polycarbonates have been studied mainly from an experimental point of view by using various techniques such as differential scanning calorimetry (DSC), powder X-ray analyses at various temperatures, and thermogravimetric analyses (TGA) . The main purpose of this paper is to investigate from a microscopic point of view to what extent the thermal degradation route of polycarbonates can be influenced by tailoring the chemical structure of the polymer backbone.…”