Dynamic mechanical spectroscopy block copolymers

Marie et al. [49] also studied the in-situ block copolymer formation via reactive blending of functionalized homopolymers. In their work, blends were characterized by SEM, DSC and dynamic mechanical spectroscopy (DMS). It should be noted that their blends (PA-6/PDMS and PS/PDMS) were composed totally using functionalized homopolymers. The different reactions under investigation were amine(NH2)/anhydride(An), amine(NH2)/epoxy(E) and carboxylic acid(COOH)/epoxy(E) (Fig. 5). 

Effects of addition of a compatibilizing block copolymer, poly(styrene-b-methyl methacrylate), P(S-b-MMA) on the rheological behavior of an immiscible blend of PS with SAN were studied by dynamic mechanical spectroscopy [Gleisner et al., 1994]. Upon addition of the compatibilizer, the average diameter of PS particles decreased from d = 400 to 120 nm. The data were analyzed using weighted relaxation-time spectra. A modified emulsion model, originally proposed by Choi and Schowalter [1975], made it possible to correlate the particle size and the interfacial tension coefficient with the compatibilizer concentration. It was reported that the particle size reduction and the reduction of occur at different block-copolymer concentrations. 

---