SMA-4000 Styrene-Maleic Anhydride Copolymer

SMA-4000 is a highest styrene content (4:1 S:MA) and highest molecular weight among the low-acid-value grades, maximizing thermoplastic compatibility and heat resistance. As a Styrene-Maleic Anhydride (SMA) copolymer with CAS 9011-13-6, it contains reactive anhydride groups that can covalently bond to amine, hydroxyl, and epoxy-functionalized surfaces — making it an effective polymeric coupling agent and reactive compatibilizer for fiber-reinforced composites and polymer alloys.

In composite materials, SMA copolymers serve as interfacial compatibilizers between hydrophilic reinforcements (glass fiber, mineral fillers) and hydrophobic thermoplastic matrices such as PP, PE, ABS, and PA. Unlike silane coupling agents which operate at the fiber surface monolayer, SMA acts as a molecular bridge across the entire interphase zone — improving tensile strength, flexural modulus, and impact retention in fiber-reinforced compounds. Recommended loading is 1–5 wt% on total compound weight.

SMA-4000 is best suited for high-performance PA/PC alloys, high-temperature composite matrix modification, and reactive extrusion processes where minimal acid functionality is preferred. It is insoluble in CCl₄, chloroform, benzene, toluene, and methanol; soluble in THF, 1,4-dioxane, and DMF; and dispersible in alkaline aqueous solutions where it hydrolyzes to the corresponding anionic maleate polymer. Available in solid powder and solution forms. Shelf life: 3 years at room temperature in original sealed packaging.