Mechanistic aspects of ester–carbonate exchange in polycarbonate/cycloaliphatic polyester with model reactions

Abstract

The reactive blending of bisphenol A polycarbonate (PC) with poly(1,4cyclohexanedimethylene-1,4-cyclohexanedicarboxylate) (PCCD) was investigated with a new high-temperature solution-blending methodology. The ester-carbonate exchange reaction (transesterification) in the blends was studied with NMR and Fourier transform infrared. The composition analysis of the PC/PCCD blends was performed with 1 H NMR, and the molecular weights were determined with viscosity methods. 1,4-Dimethylcyclohexanedicarboxylate, 1,4-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedimethanol were reacted with PC to study the tendency of polyester chain-end reactions such as transesterification, acidolysis, and alcoholysis. These model reactions revealed that the reactive blending was affected by both alcoholysis and transesterification, whereas acidolysis was absent. The model reaction products were used to study the mechanistic aspects of PC/PCCD reactive blending, which indicated the formation of three stable triads; two corresponded to symmetrical and unsymmetrical aromaticcycloaliphatic esters, and the other corresponded to aromatic-cycloaliphatic ethers. The composition analysis confirmed that in PC/PCCD reactive blending, the exchange reaction predominantly occurred in the polymer main chains, and the influence of the end groups was insignificant. The effect of the catalyst concentration and PC/PCCD composition on the extent of the exchange reaction was also investigated. Thermal analysis by differential scanning calorimetry revealed that the ester-carbonate exchange enhanced the compatibilization of PC/PCCD, and a single glass-transition temperature was observed for the miscible blends.

Small‐molecule‐induced miscibility of isosorbide‐based polycarbonate with bisphenol A polycarbonate

“…However, the results show that BPA–PC was miscible with CHDM–PC because one T g was observed in the BPA–PC/CHDM–PC (50/50) blend. This finding agreed well with previous reports and showed that BPA–PC/poly(1,4‐cyclohexanedimethylene‐1,4‐cyclohexanedicarboxylate) blends were miscible in their amorphous domains with close solubility parameters.…”

Structural and Dynamic Studies on Amido-Bridged Rhodium and Iridium Complexes

“…Surprisingly, there are few papers that report the synthesis and characterization of PCCD polymers 2, 14, 20. In particular, only one paper21 reports the use of a PCCD prepared using CHDA as monomer. However, no information and details about the synthesis are provided in the paper 21…”

“…In particular, only one paper21 reports the use of a PCCD prepared using CHDA as monomer. However, no information and details about the synthesis are provided in the paper 21…”

Effect of exchange reactions and free radical grafting on the high‐speed reactive extrusion of poly(butylene succinate) and poly(propylene carbonate) blends

“…Three types of chemical reaction can take place between PPC and PBS: alcoholysis, acidolysis, and direct ester–carbonate exchange (transesterification), see Scheme . When these reactions occur at the interface of the components, they help to increase compatibility between the phases and thus the blend performance .…”

“…Several studies of the reactive functionalization of polycondensates demonstrate that the main reaction experienced by the system is transesterification, although degradation, additional polycondensation, gel formation, and pyrolysis can also occur during the process . The molecular changes and the potential degradation of the modified blends have been analyzed by spectroscopy (such as nuclear magnetic resonance [NMR] and Fourier transform infrared [FTIR]), viscosity analysis (dynamic mechanical analysis and rheology, gel permeation chromatography), morphological changes (transmission electron microscopy, scanning electron microscopy [SEM]) and mechanical testing . Even though the exchange reaction method has proven to be successful for many polymer blends, its use in manufacturing is limited as the process is purely empirical and hard to control.…”