POLYISOBUTYLENE-TOUGHENED POLY(METHYL METHACRYLATE) .2. SMALL-ANGLE X-RAY-SCATTERING ANALYSIS OF MICRODOMAIN MORPHOLOGY OF A SERIES OF PMMA-L-PIB NETWORKS

A series of new polyisobutylene (PIB)-toughened poly(methyl methacrylate)s (PMMA) consist of PIB domains covalently bonded to a PMMA matrix. The broad maxima observed in the small-angle X-ray scattering (SAXS) profiles indicate microphase-separated materials containing PIB microdomains dispersed within a PMMA matrix. SAXS was used to determine the effect of PIB molecular weight (M(n)BAR) and weight percent (wt %) on the long period (L, repeat distance of electron density variation) in the materials. L and the maximum intensity of the scattering peak were found to increase with increasing M(n)BAR and wt % PIB, indicating larger dispersed PIB microdomains. The good agreement between measured and calculated values of the mean square electron density fluctuation, [eta2] normalized with respect to the 18K5 sample, indicates that the overall compositions of the PMMA-l-PIB networks are close to targeted values.