The competition between crystallization and demixing in polymer blends. IV. Detection of composition inhomogeneities around growing spherulites

Crystallization kinetical and morphological peculiarities in binary crystalline/crystalline polymer blends

“…The formation of dendritic or compact spherulites is determined by the competition between the displacement rate v c of the crystal growth front (i.e., the spherulite growth rate) and the diffusive displacement rate of the macromolecules 1,76,77,79 [ Fig. 2(a)].…”

“…1,67,79,84 They allow the estimation of the chain diffusion coefficient in the melt. 76,77,80 It is demonstrated by Figure 2(b) that the crossover between regimes I and III moves to lower T c (1) with increasing content in NCC.…”

“…69,76,77 Besides, theoretical con- HIGHLIGHT siderations were performed to simulate the distributions. 1,67,79,84 They allow the estimation of the chain diffusion coefficient in the melt.…”

“…The profile around an isolated spherulite may reach 50 lm into the melt, and the composition of NCC at the spherulite surface may be twice that of the initial composition or of the melt far from that surface. 76,77,80 The composition within the spherulites-overall as well as in its amorphous regionsmay correspondingly drop far below the initial composition. 80,85 In some cases, the composition changes at the crystallization site may cause a turn over of crystal modification and such of spherulite habit.…”

Phase Behavior of Poly(methyl methacrylate)/Poly(vinylidene fluoride) Blends with and without High-Pressure CO2

“…Figure 2.An illustrative phase diagram of the d8-PMMA/ PVDF system derived from the thermal characteristics of the present blend, in conjunction with critical temperatures (dashed lines) approximated by values previously reported 7,8,21,22. Homogeneous and heterogeneous regions are labeled as 1Φ and 2Φ, respectively, and the temperatures at which the data in Figure1awere collected are denoted by (O).…”