Molten bisphenol‐A polycarbonate—poly(ethylene terephthalate) blends. II. Kinetics of the exchange reaction.

Abstract

SynopsisThe kinetic aspects of the bisphenol-A plycarbonatepolyethylene terephthalate exchange reaction are studied. Though the overall mechanism of transesterification is reversible, the kinetics can be treated from a more simple model of two consecutive reactions, due to the decompoeition of the alkyl carbonate formed. T h e values of the kinetic parameters, similar to those obtained for the buphenol-A polycarbonatepolybutylene terephthalate transesterification, suggedt that the moat likely mechanism is a direct ester-ester interchange reaction which can also be catalyzed by additives such as titanium derivatives. PETPPC COFQLYESTER. REACTION 1where Ar-COO, Alk, and Ar' stand, respectively, for a terephthalate, an ethylene, and a bisphenol-A unit. However, the decompotition of aliphatic carbomtes, ati described in a previous paper,' leads to an equilibrium shift towards the right side. If we *Rr;search Associate of the National Fund for Scientific Resear&.

Transesterification reaction kinetics of poly(ethylene terephthalate/poly(ethylene 2,6‐naphthalate) blends

“…17 The most commonly used technique for studying the transesterification reaction is NMR. 24 -29 The work of Devaux and Godard et al [12][13][14][15]24,30 on PC/poly(butylene terephthalate) (PBT) and PC/PET blends shows that the reaction can be assumed to be a second-order reversible direct ester-ester interchange reaction. These results show that the rate constant (k) for PC/PET blends can be expressed as follows:…”

“…According to Devaux and Godard et al, [12][13][14][15]24,30 in terms of a direct ester-ester interchange, the overall reaction mechanism can be written as…”

Effects of composition and transesterification catalysts on the physico-chemical and dynamic properties of PC/PET blends rich in PC

“…Titanium tetrabutoxide and lead acetate hydrate were found to be the most active catalysts [10,11,[15][16][17][18]. Recently lanthanum acetyl acetonate hydrate and cobalt acetyl acetonate were used in PET/PC blending [19,20].…”

Reactive compatibilization of PC/PVDF polymer blends by zinc carboxylate containing poly(methylmethacrylate) ionomers

“…polycarbonate-g-poly(methyl methacrylate) copolymer, during the melt blending. In this respect, Rabeony et al [10], and Kyu et al [11] observed that PC could react with PMMA as result of transesterification between the ester groups of PMMA and the carbonate groups of PC, as it was also reported for other systems, such as PC and polyesters [12][13][14][15][16][17][18].…”

“…When PMMA contains acid groups, the carbonate bonds of PC can be acidolyzed [16]. This reaction has been thoroughly studied by Devaux et al [19] who proposed the following mechanism:…”