IN-SITU POLYMER BLENDS VIA CHAIN TRANSFER LIVING POLYMERIZATION (CTLP)

In-situ polymer blends of polystyrene (PS)/poly(methyl methacrylate) ( PMMA) with controlled and variable different compositions and molecula r weights were found to be successfully synthesized by ''chain transfe r living polymerization (CTLP)'' methodology by a combination of size- exclusion chromatographic analysis, differential scanning calorimetry (DSC), UV/Vis and H-1 NMR spectroscopy, and optical microscopic analys is. The PMMAs prepared in tetrahydrofuran (THF) in the presence of pol ystyrene exhibit highly syndiotactic stereoregularity (over 70 mol-%) and a glass transition temperature over 120 degrees C. A dispersed mor phology was found even for blends with over 31 vol.-% of the weight fr action of one component due to the discrepancy in the molecular weight s of two components in the PS/PMMA blends. A ternary polymer blend sys tem having PS/PMMA/PS -block- PMMA can be generated by control of the concentration of fluorene as the chain transfer agent in the CTLP.