Property Deterioration in Reactive Elastomeric Terpolymer Modified Binders During Storage at Elevated Temperatures

Abstract

Abstract Polymer-modified binders are often stored and transported at elevated temperatures, where their properties may deteriorate if mishandled. This study investigates the effect of storage temperature, storage time, base binder, and PPA concentration on the conventional and rheological properties of commercial-grade reactive elastomeric terpolymer-modified binders (RET-MBs). To mimic practical storage conditions, RET-MB was contained in sealed metal tubes and stored in a forced convection oven at temperatures of 120, 135, 150, and 165°C for up to 14 days. The results show that the deterioration in conventional and rheological properties of RET-MB was noticeable even at a low storage temperature of 135°C. At temperatures of 150 and 165°C, significant erosion in properties was observed within the first three days of storage. After 7 days of storage at 150°C, the softening point, Tu, and % elastic recovery values decrease by 4°C, 3.5°C, and 46%, respectively. One PG-grade drop can occur after 3–7 days of storage at 150 and 165°C. FTIR analysis of the solution-cast films of RET polymer reveals a strong interaction of the epoxy ring with PPA molecules to form phosphate ester linkage during storage, due to which the interaction between RET polymer and binder molecules reduces, resulting in property erosion during storage. The results show that RET-MBs should be stored and transported at temperatures < 135°C.