The results of time‐resolved light scattering for the phase separation of epoxy/polyetherimide/anhydride blends show that the evolution of scattering vector qm follows a Maxwell‐type relaxation equation. The relaxation time may be suggested as the time taken for the diffusion of the epoxy‐anhydride n‐mers from the PEI‐rich phase by their relaxation movement, and the apparent activation energy of the relaxation movement is obtained.
Values of qm versus time at different temperatures. 相似文献
To study the efficiency of different mechanisms for reactive compatibilization of polypropylene/polystyrene blends (PP/PS blends), main chain or terminal-functionalized PP and terminal-functionalized PS have been synthesized by different methods. While the in-situ block and graft copolymer formation results in finer phase morphologies compared to the corresponding non-reactive blends, the morphology development in the ternary blend system PP/PS + HBP (hyperbranched polymer) is a very complex process. HBP with carboxylic acid end groups reacts preferably with the reactive sites of the oxazoline functionalized PS (PS-Ox) and locates mainly within the dispersed PS-Ox phase. A bimodal size distribution of the PS-Ox particles within the oxazoline modified PP (PP-Ox) matrix phase is observed with big PS-Ox particles (containing the HBP as dispersed phase) and small PS-Ox particles similar in size to the unimodal distributed particles in the non-reactive PP-Ox/PS-Ox blends. Factors influencing the morphology are discussed. 相似文献
In this work, the evolution of the morphology of polypropylene/polystyrene/poly(methyl metacrylate) (PP/PS/PMMA) blends to which graft copolymers polypropylene-graft-polystyrene (PP-g-PS) of 2 compositions (55/45 and 70/30), polypropylene-graft-poly(methyl metacrylate) (PP-g-PMMA), or styrene-block-(ethylene- co-butadiene)-block-styrene (SEBS) was added has been studied. The ternary blends morphologies were predicted using phenomenological models that predict the morphology of ternary blends as a function of the interfacial tension between the blend components (spreading coefficient and free energy minimization). All blends studied presented a core-shell morphology with PS as shell and PMMA as core. The addition of PP-g-PS or SEBS resulted in a reduction of the size of the PS shell phase and, the addition of PP-g-PMMA did not seem to have any effect on the diameter of PMMA. The difference observed between the different morphologies relied on the number of droplets of core within the shell. All the phenomenological models predictions corroborated the experimental results, except when PP-g-PMMA was added to the blend. 相似文献
