INTERMACROMOLECULAR COMPLEXATION DUE TO SPECIFIC INTERACTIONS .3. MISCIBILITY AND COMPLEXATION OF PBMA AND PS(OH)

The structural changes as a function of OH concentration in the blend system of poly(n-butyl methacrylate) (PBMA) and hydroxyl-modified poly styrene (PS(OH)) are investigated by a non-radiative energy transfer t echnique and viscometry. It is shown that, for blends cast from toluen e, only 1 mol% OH concentration in PS(OH) is capable of rendering PS(O H) miscible with PBMA. When the OH concentration in PS(OH) increases t o 18 mol%, complexation is able to take place between PS(OH) and PBMA. This indicates that by progressively increasing the hydrogen bonding interaction, PS(OH)/PBMA blends can achieve immiscibility-miscibility- complexation transitions successively. For blends cast from tetrahydro furan (THF), miscibility is achieved when OH concentration increases t o 2.8 mol%, and no complexation occurs even at OH concentration as hig h as 24 mol%. In addition, the glass transition temperatures for THF-c ast blends are lower than those of the corresponding blends cast from toluene. The high glass transition temperatures for blends cast from t oluene can be attributed to an extensive degree of interpolymer hydrog en bond formation.