Representation of the synthetic route for producing controlled star/linear polymer mixtures at large quantities.
MMD determined by GPC-DRI for the three sets of samples: (a) L40k, BL40-100, (b) BL60-67, BL60-71, BL60-85, BL60-100, and (c) L90k, BL90-35, BL90-47.
(a) Comparison between the MMD of sample BL60-67 measured by GPC-DRI (line) and by GPC-MALLS (symbols). (b) Comparison between the MMD of sample BL60-67 measured by GPC-DRI (line) and obtained by combining the GPC-MALLS data of the high molar mass molecules with the GPC-DRI data of the low molar mass linear chains (symbols).
Average RMS gyration radius determined by GPC-MALLS for the three sets of samples: (a) blends BL40-XX obtained from L40k parent polymer, (b) blends BL60-XX, and (c) blends BL90-XX. The sample L90k has been used as linear reference.
Experimental MMD of the linear parent L60k (—) and MMD of calculated double linear (◻), three-arm star polymers (●), and four-arm star polymers (☆) built from the linear parent MMD.
Decomposition of the MMD of the blend BL60-67 using the GPC-DRI data of the linear parent L60k. The blend MMD (△) is measured by (a) GPC-DRI, (b) GPC-MALLS, or (c) by the combination of both GPC-MALLS and GPC-DRI data.
The horizontal (, filled symbols, referred to left axis) and vertical (, empty symbols, referred to right axis) shift factors as a function of temperature for the different 1,4-PB linear polymers and star/linear blends. The reference temperature is . The solid line through the data represents the WLF fit (see text) and the dashed line through the data represents the usual temperature-density expression of Eq. (6).
Extended creep curves for the set of star/linear blends with parent L90k. Experimental conditions: L90k, ; BL90-35, ; BL90-47, . The slope 1 associated with the flow region is shown for comparison.
Master curves of storage and loss moduli at for (a) L40k and BL40-100, (b) BL60-67, BL60-71, and BL60-100, (BL60-85 was omitted for clarity), and (c) L90k, BL90-35, and BL90-47.
(a) Inverse of the cross-over frequency: comparison between the first (Sec. ???) and second methods (Sec. ???) for the determination of blends composition. Lines represent linear fit of the data on linearized scales (standard deviations are reported in the legend). (b) Zero-shear viscosity as function of the proportion of stars (second method). Dashed lines have been drawn to guide the eyes.
van Gurp–Palmen plots of the LVE data for (a) BL60-67, BL60-71, BL60-85, and BL60-100 and (b) BL40-100, BL60-67, BL60-100, BL90-35, and BL90-47. Data of the linear samples Lmono, L40k, and L90k have been added for comparison.
MMD of the branches of a four-arm star polymer divided into five slices of same proportion (by the dashed lines). Each of these slices is represented by its average molar mass in weight (see the continuous lines).
Comparison between predicted and experimental storage and loss moduli of the blend BL60-67 by considering (continuous lines) or not (dashed lines) the “solvent” effect coming from reptation of the linear chains in the fluctuations process of the star molecules.
Storage and loss moduli. Comparison between predictions (—) and experimental data for (a) the linear sample LMono ( △, ◻), (b) the linear sample L40k ( ◻, △), and (c) the linear sample L90k ( ◻, △).
Storage and loss moduli of sample BL60-67. Comparison between experimental data ( ◻, △) and predictions (—) based on the blend composition found from (a) the GPC-DRI data: 42% of linear chains, 6.6% of double linear chains, 13.6% of three-arm stars, and 37.8% of four-arm stars, (b) the GPC-MALLS data: 20.4% of linear chains, 33.5% of double linear chains, 0% of three-arm stars, and 46.1% of four-arm stars, and (c) the combination of GPC-DRI and GCP-MALLS data: 40% of linear chains, 8.3% of double linear chains, 8.5% of three-arm stars, and 43.3% of four-arm stars.
Storage and loss moduli. Comparison between predictions (—) and experimental data ( ◻, △) for (a) the blend BL60-71 [with and without (---) considering the reptation of the three-arm stars]. Its composition is of (linear, double linear, three-arm, four-arm) 31.5%, 5.8%, 34%, 28,7%, (b) the blend BL60-85 with a composition of 19.8%, 0%, 43.6%, 36.6%, (c) the blend BL60-100 with a composition of 5.7%, 12.6%, 61.8%, 20.9%, (d) the blend BL90-35 with a composition of 71.7%, 1.5%, 10.2%, 16.6%, (e) the blend BL90-47 with a composition of 47%, 11.5%, 18.7%, 22.8%, (f) the blend BL40-100 with a composition of 0%, 45.35%, 51.45%, 3.2%.
Molecular characteristics of the linear polymers used.
Molecular characteristics of the star/linear polymer blends used.
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