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“The values are determined applying eqs 1, 4, and 7 to experimental data for 11 representative systems with a range of dynamic heterogeneities (AT,’s between ~10 aad 200 K). > PHB, PCL and PC are the Semicrystalline components. Table 2. Comparison of the R? Values and the Reduced y-Square 77/DoF Values

Table 2 “The values are determined applying eqs 1, 4, and 7 to experimental data for 11 representative systems with a range of dynamic heterogeneities (AT,’s between ~10 aad 200 K). > PHB, PCL and PC are the Semicrystalline components. Table 2. Comparison of the R? Values and the Reduced y-Square 77/DoF Values

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“The weight fraction of the semicrystalline component in a blend, above which its partial crystallization appears, is indicated. Table 1. Mixture Information and Curve-Fitting Results for the Parameters Incorporated in Eq 7*
“The weight fraction of the semicrystalline component in a blend, above which its partial crystallization appears, is indicated. Table 1. Mixture Information and Curve-Fitting Results for the Parameters Incorporated in Eq 7*
Figure 1. Compositional variation of blend T, for miscible binary polymer mix- tures, which obey or are very close to the ideal mass-additivity behavior (PTA + PVME and PECH + PHB) and blends that exhibit departure from it (PS + PPE- 3100 and PTT + PET).
Figure 1. Compositional variation of blend T, for miscible binary polymer mix- tures, which obey or are very close to the ideal mass-additivity behavior (PTA + PVME and PECH + PHB) and blends that exhibit departure from it (PS + PPE- 3100 and PTT + PET).
Figure 2. Compositional variation of blend T, for the miscible polymer blend PVE + PI. The deviation from linearity plot is shown in the insert.
Figure 2. Compositional variation of blend T, for the miscible polymer blend PVE + PI. The deviation from linearity plot is shown in the insert.
Figure 3. Linear fitting of the dependence between the principal parameter of the proposed equation, ao, and the parameters of (a) the Gordon-Taylor, ker, or (b) the Jenckel-Heusch equation, 6 [b = ap(Tgo — T,,1)]. The data in these plots involve miscible binary polymer blends for which parameter az is zero. Note that for blends with a; 4 0, the ratio ao(Tg2 — Tz1) is also nearly equal to b. The errors in the values are comparable to the size of the symbols unless other- wise indicated.
Figure 3. Linear fitting of the dependence between the principal parameter of the proposed equation, ao, and the parameters of (a) the Gordon-Taylor, ker, or (b) the Jenckel-Heusch equation, 6 [b = ap(Tgo — T,,1)]. The data in these plots involve miscible binary polymer blends for which parameter az is zero. Note that for blends with a; 4 0, the ratio ao(Tg2 — Tz1) is also nearly equal to b. The errors in the values are comparable to the size of the symbols unless other- wise indicated.
Figure 4. Compositional variation of blend T for the miscible polymer blends of (a) PEI + PBI and (b) PMMA + CAP. In each case, the deviation from line- arity plot is shown in the insert.
Figure 4. Compositional variation of blend T for the miscible polymer blends of (a) PEI + PBI and (b) PMMA + CAP. In each case, the deviation from line- arity plot is shown in the insert.
Figure 5. Compositional variation of T, for the mis- cible polymer blends PxaMS + PCHMA. rFarameter dg 1S zero 1n the alorementioned examples of polymer mixtures, in agreement with the assumed moderate complexity of their behav- ior. Nevertheless, there exist interesting cases of “anomalous” changes in the dynamics of mixtures with components of nearly equal T,. The intrigu- ing behavior involves either positive! >? or nega- tive’ departures from the mass-additivity rule, which are accompanied by blend T,s not interme- diate to those of the blend components. In an attempt to explain this phenomenon several sce- narios have been invoked; for example, either changes in volume due to blending (i.e., positive or negative excess volume), changes in the inter- molecular constraints, or nonrandom mixing. No matter the cause, this anomaly produces signifi- cant positive or negative values for az. Character- istic examples provide the miscible blends of poly(«-methyl styrene) (PaMS) with poly(cyclo- hexyl methacrylate) (PCHMA)*? and of PECH with PVME,” in which the 7, of some blends is above the highest neat component value (T',2). For example, in the PxaMS + PCHMA system (Fig. 5), the ao, b, and kgr values strongly depart from the linear ag versus kay and 6b versus ao dependences established by the data included in Figure 3. This behavior is consonant with the dis- tinctly nonzero value of our third parameter. Note that in this case also, the proposed equation
Figure 5. Compositional variation of T, for the mis- cible polymer blends PxaMS + PCHMA. rFarameter dg 1S zero 1n the alorementioned examples of polymer mixtures, in agreement with the assumed moderate complexity of their behav- ior. Nevertheless, there exist interesting cases of “anomalous” changes in the dynamics of mixtures with components of nearly equal T,. The intrigu- ing behavior involves either positive! >? or nega- tive’ departures from the mass-additivity rule, which are accompanied by blend T,s not interme- diate to those of the blend components. In an attempt to explain this phenomenon several sce- narios have been invoked; for example, either changes in volume due to blending (i.e., positive or negative excess volume), changes in the inter- molecular constraints, or nonrandom mixing. No matter the cause, this anomaly produces signifi- cant positive or negative values for az. Character- istic examples provide the miscible blends of poly(«-methyl styrene) (PaMS) with poly(cyclo- hexyl methacrylate) (PCHMA)*? and of PECH with PVME,” in which the 7, of some blends is above the highest neat component value (T',2). For example, in the PxaMS + PCHMA system (Fig. 5), the ao, b, and kgr values strongly depart from the linear ag versus kay and 6b versus ao dependences established by the data included in Figure 3. This behavior is consonant with the dis- tinctly nonzero value of our third parameter. Note that in this case also, the proposed equation
Figure 6. Comparison of the compositional variation of the glass transition temper- atures observed in miscible blends of PVME with (a) PVPh, (b) P2CS, and (c) PS. An unusual plot (observed only in PVME + PVPh) of the T,-deviation from the weighted-average blend T, is shown in the insert.
Figure 6. Comparison of the compositional variation of the glass transition temper- atures observed in miscible blends of PVME with (a) PVPh, (b) P2CS, and (c) PS. An unusual plot (observed only in PVME + PVPh) of the T,-deviation from the weighted-average blend T, is shown in the insert.
Figure 7. Compositional variation of blend T, for the miscible PMMA + PVPh polymer blend. The plot of the deviation from linearity is shown in the insert.
Figure 7. Compositional variation of blend T, for the miscible PMMA + PVPh polymer blend. The plot of the deviation from linearity is shown in the insert.
Journal of Polymer Science: Part B: Polymer Physics DOI 10.1002/polb
Journal of Polymer Science: Part B: Polymer Physics DOI 10.1002/polb
Figure 9. (a) Compositional variation of T, data (@) of Miwa et al.’* for PVME + PoCIS blends. (b) Effec- tive Ts (Ml) of components versus gpymr. Explanation in text.
Figure 9. (a) Compositional variation of T, data (@) of Miwa et al.’* for PVME + PoCIS blends. (b) Effec- tive Ts (Ml) of components versus gpymr. Explanation in text.
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EngineeringPolymer BlendsPolymer BlendIntermolecular Interaction
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