Abstract. Intrinsic fluorescence method was applied to study the miscibility and interactions of thermoplastic phenol formaldehyde resin (TPF) / poly(!-caprolactone) (PCL) blends. The characteristic intrinsic fluorescence emission of TPF at 313 nm showed the very good sensitivity to monitor the macromolecular chain motion in the TPF/PCL blends. The glass transition (T g ), crystallization (T c ), and melting transition point (T m ) of TPF/PCL blends were measured by the temperature dependence of intrinsic fluorescence intensities upon heating or cooling process. Interestingly, when TPF/PCL " 5/5, besides a T g for the amorphous phase of blend, another transition at temperature a little higher than T g of PCL can be observed by intrinsic fluorescence method. This microheterogeneity can be explained by the so-called 'rigid amorphous phase' (RAP) due to the good flexibility and the strong self-association of PCL chains in amorphous phase. Besides, the analysis of the dependence of T g on the content of PCL suggests that this microheterogeneity can attenuate the interactions between TPF and PCL chains and result in a lowering of T g s of blends. In view of the simplicity and sensitivity of measurement as well as affordability of instrument, intrinsic fluorescence proved to be an effective means for characterization of microstructural variation in polymer blends.

Abstract.Intrinsic fluorescence was applied to quantitatively describe the interfacial adhesion of nanoparticles in polystyrene/poly(vinyl methyl ether) (PS/PVME) blends. Due to the aggregation of aromatic rings on PS chains, the temperature dependence of excimer fluorescence intensity (I 324 ) showed the high sensitivity to the phase separation process. Consistent with Ginzburg thermodynamic model, it was found that the addition of spherical hydrophilic nanoparticles shifted the phase separation temperature to higher temperatures due to the aggregation of silica into PVME chains leading to the free energy reduction and slowing down the phase separation dynamics. A certain composition of polymer blend, i.e. 2/8, was focused on to shed light on the dynamic of spinodal decomposition (SD) phase separation by using decomposition reaction model. It was shown that the addition of nanoparticles to polymer blends resulted in the deviation of linear relationship between the initial SD phase separation rate (R p0 ) and thermodynamic driving force (!f SD ). Besides, for PS/PVME (2/8) with 2 vol% silica nanoparticles, the apparent activation energy of phase separation (E a ) was 196.61 kJ/mol, which was higher than that of neat PS/PVME (2/8) blend (E a = 173.68 kJ/mol), which strongly confirmed the interfacial adhesion effect of silica nanoparticles as compatibilizers.