New miscible elastomer blends from acrylate rubber and fluorocarbon rubber

摘要

Blends of acrylate rubber (ACM) and fluorocarbon rubber (FKM) were studied for their miscibility, using infrared (IR) spectroscopy, nuclear magnetic resonance (H-1 NMR) spectroscopy, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC). The IR studies indicated a band shift of the carbonyl group of ACM towards lower frequency, with an enthalpy of interaction in the range of 1-2 kcal/mol, corresponding to the value of weak hydrogen bonding or strong dipole-dipole type of interaction between the C=O and -CF3 groups in the blend. H-1 NMR spectra showed a peak shift of the -CH proton of ACM towards lower delta values due to a decrease in the deshielding effect. The blends were found to be miscible in all composition ranges, showing a single sharp tan delta (max) corresponding to the glass-transition temperature in DMTA. The presence of strong specific interaction was supported by an increase in mechanical properties of the blends showing maximum interaction in 30/70 (w/w) of ACM/FKM blend. [References: 27]