COMPATIBILIZATION OF BLENDS OF POLYBUTADIENE AND POLY(METHYL METHACRYLATE) WITH POLY(BUTADIENE-BLOCK-METHYL METHACRYLATE)

Compatibilization of blends of polybutadiene and poly(methyl methacryl ate) with butadiene-methyl methacrylate diblock copolymers has been in vestigated by transmission electron microscopy. When the diblock copol ymers are added to the blends, the size of PB particles decreases and their size distribution gets narrower. In PB/PMMA7.6K blends with P(B- b-MMA)25.2K as a compatibilizer, most of micelles exist in the PMMA ph ase. However, using P(B-b-MMA)38K as a compatibilizer, the micellar ag gregation exists in PB particles besides that existing in the PMMA pha se. The core of a micelle in the PMMA phase is about 10 nm. In this ar ticle the influences of temperature and homo-PMMA molecular weight on compatibilization were also examined. At a high temperature PB particl es in blends tend to agglomerate into bigger particles. When the molec ular weight of PMMA is close to that of the corresponding block of the copolymer, the best compatibilization result would be achieved. (C) 1 998 John Wiley & Sons, Inc.