Reactive Compatibilization of Polycarbonate and Poly(methyl methacrylate) in the Presence of a Novel Transesterification Catalyst SnCl₂·2H₂O

Abstract

We compare the effectiveness of various known organometallic transesterification catalysts with a novel SnCl(2)·2H(2)O transesterification catalyst in the formation of homogeneous PC/PMMA blends with single T(g). It is shown that SnCl(2)·2H(2)O works more efficiently than the other organometallic transesterification catalysts. Even 0.1% (wt/wt) of SnCl(2)·2H(2)O is enough to establish an interaction between PC and PMMA phases, leading to the formation of a homogeneous PC/PMMA blend with single T(g) and single degradation temperature. FTIR, (1)H NMR, and XRD studies provide evidence of the formation of PC-g-PMMA graft copolymer, which acts as a compatibilizer between the PC and PMMA phases. A significant improvement in the optical transparency of the PC/10PMMA blend prepared using SnCl(2)·2H(2)O catalyst as compared with PC/10PMMA without any catalyst is observed. There is also a change in the morphology from granular in uncompatibilized blends to lamellar in the compatibilized blends.

The Morphological properties of SnCl2·2H2O-modified PC/PMMA blends

“…Besides, the TGA results show that there is approximately 10 % residual mass that might be due to the small molecular residue which has contained benzene. The result is in accordance with Singh's study of the reactive compatibilization of polycarbonate and poly (methyl methacrylate) in the presence of SnCl 2 ·2H 2 O[18].…”

“…The possible explanation may be that SnCl 2 ·2H 2 O has promoted the ester-exchange reactions between PC and PMMA and formed the PC-g-PMMA graft copolymer [17]. The reaction scheme shown in Scheme 1 is in accordance with the study of Singh et al [18] When the SnCl 2 ·2H 2 O content reaches 0.100 % (wt) (Fig. 2f), there is not a clear and distinct PMMA dispersed phase observed, because PMMA is fully converted to PC-g-PMMA copolymer which cannot be dissolved in acetone.…”

Synthesis of luminescent polycarbonate grafted with methyl methacrylate/europium complex using supercritical CO2 technology as a green chemistry method

“…The PC-g-MMA/Eu(TTA) 3 AA samples were labeled by considering the time of impregnation used in each experiment. In the spectra of the polymers, it is observed two new bands at 1464 and 1597 cm -1 , owing to b-diketone ligand present in europium complex [23]. It was also observed an increase in the intensity of the bands at 1187 cm -1 (C-O stretching vibration of[CH 3 O-groups), at 1015 cm -1 (C-H asymmetrical stretching of[CH 2 groups), and at 761 cm -1 (C-H stretching vibration of[CH 2 groups).…”

“…However, the decrease in the thermal stability of PC8 and PC10, occurred in two steps of degradation, and corresponds to both PMMA and PC. The occurrence of two-step degradation indicates a lower interaction between the PC/MMA/Eu(TTA) 3 AA phases, which is attributed to the larger amount of grafted MMA/ Eu(TTA) 3 AA [23]. In such a case, there is a sharp decrease of degradation temperature (*100°C) that can be attributed to higher ratio of grafted monomers in the PC, which increased the amount of radicals during grafting process causing more points of breakage on the PC chains, and also suggests still formation of larger chains of MMA/ Eu(TTA) 3 AA polymers which hinder the interaction of grafted PMMA chains with PC chains.…”

Improving transparency of incompatible polymer blends by reactive compatibilization

“…The transparency of the blends can be improved if the dispersed phase is sufficiently small. However, the results are seldom attributed to the difficulty in reducing the domain size to a sufficiently small value [10,11].…”