Characterization of Binary and Tertiary Blends of SBR, NBR, and PVC by Mid and Near IR Spectroscopy

摘要

NBR/PVC blends are widely used in hoses, gaskets, shoe soles, and as coatings in the electrical industry. In some applications, a small portion of the NBR in NBR/PVC blends is replaced by E-SBR to reduce raw material cost. NBR/SBR blends are used to compensate for the volume decrease in oil seal applications. The properties of these polyblends are sensitive to small variations in the amounts of the individual polymers used. To estimate the blend compositions with a reasonable accuracy, the elastomer industry needs a variety of analytical test methods that can be used under a variety of experimental conditions. In this study, the feasibility of using mid-IR and near-IR spectroscopy to estimate the amount of NBR, PVC, and SBR in blends that are composed of varying ratios of the three elastomers was investigated. In the mid-IR region, the amount of each elastomer in the blends was obtained from a plot of the absorbance ratio (Absorbance of the characteristic peak for SBR, PVC, or NBR/Absorbance of the C=C stretching vibration of polybutadiene) vs. the amount of each component in the blend. The polymeric composition of the blends was also determined by an FTIR with an ATR attachment using a calibration curve generated from a plot of the absorbance of the characteristic peak for each elastomer vs. the polymeric content of a series of standards. The calibration curve for near IR was developed from a partial-least-squares algorithm.