Effect of di‐n‐dodecyl phosphate on the transesterification reaction in a poly(butylene terephthalate)/polycarbonate blend

Abstract

ABSTRACT:The transesterification behavior of a poly (butylene terephthalate) (PBT)/polycarbonate (PC) blend with the addition of di-n-dodecyl phosphate was studied with differential scanning calorimetry (DSC) and infrared spectroscopy. The effects of triphenyl phosphate (TPP) and di-n-dodecyl phosphate on the suppression of transesterification were compared. The differences in the crystallization and melting temperatures during the two heating and cooling cycles in the DSC measurements were lower than those of the virgin PBT/PC blend, and di-n-dodecyl phosphate inhibited the formation of a random copolyester but did not suppress the formation of a block copolyester. The crystallization temperature of the PBT/PC blend in the presence of di-n-dodecyl phosphate was higher than that of the blend in the presence of TPP. Din-dodecyl phosphate was thus more effective than TPP in the inhibition of transesterification between PBT and PC.

PBT/PC Blends Compatibilized and Toughened via Copolymers in Situ Formed by MgO-Catalyzed Transesterification

“…And usually the PBT/PC blends may undergo three types of transesterification reactions: acidolysis (reaction between the carboxyl end groups of PBT and the carbonate groups of the PC), alcoholysis (reaction between the hydroxyl end groups of PBT and the carbonate groups of PC), and direct transesterification (reaction between the ester groups of PBT and the carbonate groups of PC). Generally, the direct transesterification is the major exchange reaction between PBT and PC . Progressive transesterification reactions lead to a transformation of the initial homopolymers into block copolymers and finally into random copolymers. − And these formed substances (“copolymers”) can act as compatibilizer for PBT and PC. ,, However, the copolymers formed via transesterification usually are limited, which made the interphase adhesion of PBT and PC poor.…”

“…Generally, the direct transesterification is the major exchange reaction between PBT and PC . Progressive transesterification reactions lead to a transformation of the initial homopolymers into block copolymers and finally into random copolymers. − And these formed substances (“copolymers”) can act as compatibilizer for PBT and PC. ,, However, the copolymers formed via transesterification usually are limited, which made the interphase adhesion of PBT and PC poor. So the commercial PBT/PC blends present unsatisfactory mechanical properties, especially the notched impact strength, for example, their notched impact strength is less than 10 kJ/m 2 when PBT is the dominant component.…”

“…Generally, the direct transesterification is the major exchange reaction between PBT and PC. 7 Progressive transesterification reactions lead to a transformation of the initial homopolymers into block copolymers and finally into random copolymers. 7−10 And these formed substances ("copolymers") can act as compatibilizer for PBT and PC.…”

Modification of the core–shell ratio to prepare PB-g-(MMA-co-St-co-GMA) particle-toughened poly(butylene terephthalate) and polycarbonate blends with balanced stiffness and toughness

“…[3][4][5][6][7][8] Poly(butylene terephthalate) (PBT) and polycarbonate (PC) are an important pair for polyester blends and they have been investigated in detail in recent years. [9][10][11][12][13][14][15] Most of the research on PBT/PC blends was focused on transesterication reactions, miscibility, crystallization properties and phase morphologies. The PBT/PC blends combine the excellent chemical resistance and easy processability of the PBT phase with the good dimensional stability and higher mechanical properties of the PC phase.…”

Study on the Reaction and Thermo-Physical Properties of PC and PBT Blend

“…The residual catalyst of PBT enforces the transesterification under the molten state [4]. The transesterification is the most important exchange reaction between PC and PBT [5]. The progressive transesterification finally forms into random copolymers.…”