Orientation Development and Properties in Styrene/Maleic Anhydride Copolymers

Abstract

Styrene/maleic anhydride copolymers have been introduced com mercially for microwave food packaging applications. The conversion of the vis ibly transparent grades requires biaxial orientation of extruded sheet in order to render the sheet suitable for thermoforming. The optimum process condi tions must be defined to produce the desired level of molecular orientation for the particular thermoforming application. This article will discuss the sensi tivities of styrene/maleic anhydride copolymer structures and properties to molecular distributions, formulation modifications and processing variables.