Composition Dependence of the Interaction Parameter in Isotopic Polymer Blends

Londono, J. D.; Narten, A. H.; Wígnall, G. D.; Honnell, Kevin G.; Hsieh, E. T.; Johnson, Timothy W.; Bates, Frank S.

doi:10.1021/ma00088a029

Cited by 121 publications

(227 citation statements)

References 5 publications

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“…Similar downturn composition dependencies of the interaction parameter have been observed for other isotopic mixtures. [47][48][49] The results reported here are in good agreement with values from Beaucage et al for isotopic symmetric equimolar mixtures of linear H/D PDMS. In that work, interaction parameters were evaluated from the SANS profiles as a function of molecular weight and temperature, and this made it possible to establish a general relationship between , M w , and T:…”

Section: Interaction Parameterssupporting

confidence: 91%

Conformation of Cyclics and Linear Chain Polymers in Bulk by SANS

Arrighi¹,

Gagliardi²,

Dagger³

et al. 2004

Macromolecules

123

132

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Small-angle neutron scattering (SANS) has been used to investigate the conformation of linear and cyclic poly(dimethylsiloxane)s (PDMS) in chemically identical, undiluted blends. SANS measurements have been carried out on (1) linear hydrogenous (H) mixed with linear deuterated (D) PDMS and (2) cyclic H mixed with cyclic D PDMS. The conformational behavior of the cyclic and linear polymers is studied over a wide range of molar mass and composition. Isotopic blends of linear PDMS are shown to adopt conformations that agree well with theoretical predictions for Gaussian random-coil polymers and confirm previous SANS studies. As expected for chains obeying Gaussian statistics, the mean radii of gyration, R g, scale with the weight-average molar mass as Rg ∝ Mw 0.5 . A detailed study of H/D cyclic PDMS mixtures is presented, and we demonstrate that, since Rg ∝ Mw 0.4 , highly flexible cyclic polymers in the melt adopt an even more compact conformation than that of unperturbed rings. This behavior confirms previous predictions based on computer simulations and theoretical studies. The results are in excellent agreement with computer simulations and theoretical predictions reported in the literature.

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Section: Interaction Parameterssupporting

confidence: 91%

Conformation of Cyclics and Linear Chain Polymers in Bulk by SANS

Arrighi¹,

Gagliardi²,

Dagger³

et al. 2004

Macromolecules

123

132

View full text Add to dashboard Cite

show abstract

“…In all three 50/50 mixtures, the associated parameters were consistent within the uncertainty with a weak nonideality due to the isotope effect. [37][38][39][40][41] …”

Section: Isotopic Blendsmentioning

confidence: 99%

Entropically driven phase separation of highly branched/linear polyolefin blends

Chen

Lodge

Bates

2000

J. Polym. Sci. B Polym. Phys.

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“…One such parameter is f. For a number of polymer blends, experimental evidence has suggested that f is an important parameter which directly contributes to the definition of w AB . In general this observation has been limited to two classes of blends: LCST systems, [4] as discussed above, and isotopic polymer blends [5]. The rationale for this deviation from FHT is related to local effects which invalidate the meanfield assumptions used to derive Eq.…”

Section: Effect Of Mixture Composition On Polymer Miscibilitymentioning

confidence: 99%