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Nanostructured glassy-crystalline blends were obtained by reactive blending of poly(methyl methacrylate) (PMMA), or of poly(methyl methacrylate)-b-poly-(n-butyl acrylate)-b-poly(methyl methacrylate) (MBM) triblock copolymer, with polyamide-6 (PA). The PMMA chain, or block, contains a low fraction of glutaric anhydride units which are strongly reactive toward the terminal amino group of PA. Under the blending conditions the grafting reaction is very efficient leading to a high fraction of graft copolymer. When the PA is short, Mn = 2500, nanostructured blends are obtained with both PMMA and MBM while for longer PA, Mn = 15000, nanostructures form only with the triblock MBM copolymer. The intrinsic property of MBM to self-organize in lamellar-like morphology seems to favour the nanostructure formation in the final blend. The resulting materials exhibit unique properties such as transparency, creep resistance and solvent resistance.

Reactive blending is used as a tool for the synthesis of graft copolymers of poly(methyl methacrylate) and polyamide-6 (PMMA-g-PA). The grafting reaction occurs between the amino end group of PA and glutaric anhydride units randomly distributed along the PMMA backbone. The anhydride units are formed by thermal treatment (typically above 180 °C) of a precursor PMMA bearing a low fraction of methacrylic acid units (5 or 10 mol %). With this method, it is possible to control the amount of anhydride units without degradation or cross-linking of the PMMA chains. The resulting blends with PA are characterized by size exclusion chromatography in benzyl alcohol at 130 °C and selective extraction of ungrafted PMMA chains. Combining these techniques, we were able to estimate the fraction and the average composition of the graft copolymers synthesized in situ during the blending process. High fractions of graft copolymer (35−75 wt %) are obtained in all the blends studied in this work. A higher amount of graft copol...

Nanostructured blends of poly(methylmethacrylate) and polyamide-6 (PMMA/PA6) were prepared by reactive blending. The grafting reaction occurs between the amino end-group of PA6 and glutaric anhydride units randomly distributed along the backbone of PMMA. Short PA6 grafts were used to facilitate reaction at the interface. Very fine morphologies were obtained after blending. Annealing the blends above the melting point of polyamide reveals that the amount of anhydride present on PMMA chains controls self assembly of the blends and stability of the copolymer at the interface. In some cases, stable swollen lamellar assemblies were achieved. These materials exhibit interesting properties such as transparency, creep resistance and solvent resistance.