Methyl Methacrylate Butadiene Styrene

(Impact Modified Styrene Methyl Methacrylate)

Properties

Methyl methacrylate-butadiene-styrene (MBS, MMBS), also known as impact modified styrene methyl methacrylate (SMMA), has rubber particles dispersed throughout its methyl methacrylate-styrene polymer matrix. It is a clear engineering and commodity thermoplastic that has excellent transparency1, high impact strength, good stiffness and good resistance to many chemicals. It is also easy to mold using standard equipment including calendering, extrusion, blow and injection molding and can be easily colored.

The properties of acrylic copolymers depend on their composition and morphology; the butadiene portion provides flexibility and high impact resistance whereas the methacrylate-styrene matrix provides strength, good dimensional stability, and creep resistance. Commerical grades possess very high toughness3, good low temperature performance and easy processability.

MMBS is widely used in the packaging, medical, household appliances and consumer goods industries. Important applications include (transparent and toughened) toys, reusable drinkware, office accessories, (industrial) housings and covers, and medical devices. Some special grades, the so-called MBS core-shell resins, find uses as impact modifiers (IM). Commerical grades are tailored to the needs of specific applications and are suitable for both thermoset and thermoplastic resins including polymethacrylate, polybutylene terephthalate, polyvinylchloride, and polycarbonate (PC) as well as its blends PC/ABS, PC/PET, and PC/PBT.

Manufacturers

Brand Names

1The refractive index of the plastic matrix and that of the rubber particles are typically adjusted to be equal so that MBS resins are fully transparent.2
2J. Takahashi, H. Watanabe, J. Nakamoto, K. Arakawa and M. Todo, Polymer Journal, 38 (8), pp. 835–843 (2006)
3Certain grades provide toughness comparable to some grades of polycarbonate.