Fourier transform infrared analysis of polycarbonate/epoxy mixtures cured with an aromatic amine

Abstract

In our previous article, we established that polycarbonate (PC) can react with the diglycidyl ether of bisphenol-A (DGEBA) at 200ЊC through transesterification and addition reactions, resulting in degraded PC chains with phenolic end groups and also in PC/DGEBA copolymers. However, these reactions can be minimized or eliminated at lower temperatures, below 160ЊC. In this article, Fourier transform infrared analysis (FTIR) was used to study the curing kinetics of epoxies in the presence of PC. The curing agent was an aromatic amine, diaminodiphenyl methane (DDM). FTIR results showed that the presence of a small amount of PC promoted the amineepoxide reactions, probably due to the catalytic effect of the phenolic end groups in the PC chains. However, the PC did not alter the epoxy cure reaction mechanism. Two different blending processes were used to premix the PC and DGEBA, namely, solutionblending and melt-blending processes, in order to give different extents of prereactions. If a solution-blending process was used, PC tended to undergo crystallization during an early stage of cure. When a melt-blending process was used, no melting peak was observed in the thermograms of the differential scanning calorimeter (DSC) for the modified epoxies; PC chains bonded to DGEBA during prereaction at 200ЊC, thus inhibiting the crystallization of PC during cure.

Frequency dependent and surface characterization of DNA immobilization and hybridization

“…Fourier transform infrared spectra for GPS and DNA on standard glass microscope slides. 910 cm −1 , which is characteristic to the epoxy group (Don and Bell, 1998;Lee et al, 2003). Fig.…”

Synthesis and Characterization of Epoxy/MCDEA Networks Modified with Imidazolium‐Based Ionic Liquids

“…FTIR analysis constitutes a powerful tool for evaluating the cure reaction of epoxy pre-polymers [28][29][30][31][32][33] and was also employed in this study to monitor the reaction between DGEBA and IL. Figure 7 illustrates the spectra of [DiOImid][I] (curve A), DGEBA (curve B) and their blends containing 20 phr of IL prepared at room temperature (curve C) and at 100 8C for 10 min (curve D).…”

Combinatorial Approach to Characterizing Epoxy Curing

“…The base-line corrected FTIR spectra of eight discrete films in the 800 cm À1 to 953 cm À1 spectral region are shown in Figure 1. The peak at 916 cm À1 , which is associated with the epoxide ring absorbance of the DGEBA molecule, [9,11] decreases monotonically with increasing curing temperature. The gradual decrease of this peak reflects the reaction of epoxide rings to form ether linkages.…”

“…The CHT techniques for sample characterization need to be nondestructive and time efficient. Consequently, combinatorial approaches to materials science require the development of flexible techniques that work in unison to produce a complete picture of mechanical, [4] kinetic [5,6] or adhesive [7][8][9] processes.…”

“…[9][10][11] Transmission FTIR microspectroscopy has been applied previously to cross-sections of bilayers of epoxy blends. [12] FTIR-RM mapping is a non-contact, non-destructive method for characterizing surface chemical composition both qualitatively and quantitatively.…”