The solution of plastics prediction problems by thermoanlytical techniques

Often the first step in the solution of problems concerning the use of plastics involves the detailed characterization of a particular resin. Typically, a commercial plastic is composed not only of the basic resin but also of many additional additives. These additives may be such things as impact modifiers, plasticizers, flame retardants, and molding lubricants. In our laboratory we have developed thermoanalytical techniques for the determination of the morphology and composition of these multiphase materials. Specifically, we have quantitatively analyzed an ABS resin for not only the amount of SAN and BD but also the concentration of a molding lubricant (ML) in the resin. The concentration of BD and SAN was estimated calorimetrically from Δ C p measurements at T g , and the ML level was calculated from Δ H f determinations. In addition, the shifts in T g of both the BD and SAN phases of the ABS were studied as a function of diluent concentration. The diluents in these resins are residual monomers or other “impurities”.