Effect of nematic interaction in the orientational relaxation of polymer melts

Doi, Masao; Pearson, Dale S.; Kornfield, Julie; Fuller, Gerry

doi:10.1021/ma00193a082

Cited by 73 publications

(79 citation statements)

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“…After speaking about these results at various conferences it was pointed out to me [14] that experimentally the coupling between segmental orientation of di¤erent chains has been known for long time ( [15], [16], [17] and references therein); it was attributed to nematic interactions between the backbones [18]. However, our current model has only excluded volume interactions, which produce all the coupling (in agreement with assumptions of ref.…”

supporting

confidence: 84%

Whither tube theory: From believing to measuring

Likhtman

2009

Journal of Non-Newtonian Fluid Mechanics

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supporting

confidence: 84%

Whither tube theory: From believing to measuring

Likhtman

2009

Journal of Non-Newtonian Fluid Mechanics

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“…This`orientational coupling' has also been seen in labelled NMR experiments (see below), and conjectured to arise from small nematic chain±chain interactions or, more directly, from the excluded-volume screening interaction [160]. In either case, the presence of such an interaction does not a ect the validity of the stress-optical law as a whole [161,162] (note that this is not the case when there is ®nite macroscopic nematic order [31]), but means that local identi®cation of contribution of segmental orientation to stress needs to be treated with caution.…”

Section: Birefringence and Dichroismmentioning

confidence: 69%

“…where u is the tangent vector of the primitive path, …t † is the shear rate and ½ d is the reptation timeÐwe recognize the double-contraction as proportional to the relative velocity of chain and tube in equation (161). The O…1 † number is necessary for the same reason as the equivalent constant c¸we introduced in linear response CR: the number of CR events required for each local tube reorientation is unknown.…”

Section: Convective Constraint Release (Ccr)mentioning

confidence: 99%

Tube theory of entangled polymer dynamics

McLeish

2002

Advances in Physics

827

1,122

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The dynamics of entangled¯exible polymers is dominated by physics general to many chemical systems. It is an appealing interdisciplinary ®eld where experimental and theoretical physics can work closely with chemistry and chemical engineering. The role of topological interactions is particularly important, and has given rise to a successful theoretical framework: the`tube model'. Progress over the last 30 years is reviewed in the light of specially-synthesized model materials, an increasing palette of experimental techniques, simulation and both linear and nonlinear rheological response. Our current understanding of a series of processes in entangled dynamics:`reptation',`contour length¯uctuation' and`constraintrelease' are set in the context of remaining serious challenges. Especial attention is paid to the phenomena associated with polymers of complex topology or`long chain branching'.

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“…[1][2][3] Later, it was found that the nematic interaction is expected also in miscible polymer blends. [4][5][6][7][8] Furthermore, even plasticizer molecules are found to orient to the stretching direction by the alignment of polymer chains.…”

Section: Introductionmentioning

confidence: 99%

Orientation birefringence of cross-linked rubber containing low-mass compound

Kiyama

Nobukawa

Yamauchi

2015

AIP Conference Proceedings

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Molecular orientation of low-mass compounds (LMCs) in a cross-linked rubber is studied in order to obtain the basic information on the dynamics of LMC molecules in a polymer beyond the glass transition temperature. A small amount of LMCs such as 4-cyano-4'-pentylbiphenyl (5CB), tricresylphosphate (TCP), and styrene-based tackifier (TF) is added into polybutadiene rubber (BR). After cross-linking reaction, the sheet samples are used to evaluate the orientation birefringence during stretching and stress relaxation. The rectangular films, cut out from the cross-linked sheets, are set in a uniaxial stretching machine equipped with an optical system to measure both birefringence and tensile stress simultaneously. It is confirmed that orientation birefringence is proportional to the stress for not only pure cross-linked BR, but also cross-linked BR containing an LMC in a wide range of strain. Even after stretching, the birefringence does not change as far as the sample is kept at a constant strain. The results suggest that the LMC molecules are forced to orient with polymer chains by the strong intermolecular orientation correlation. Because of the LMC orientation, the stress-optical coefficient CR is enhanced by the addition of 5CB and TCP, but depressed by TF. Therefore, the LMC doping can be used to control the birefringence of a retardation film.

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Effect of nematic interaction in the orientational relaxation of polymer melts

Cited by 73 publications

References 0 publications

Whither tube theory: From believing to measuring

Whither tube theory: From believing to measuring

Tube theory of entangled polymer dynamics

Orientation birefringence of cross-linked rubber containing low-mass compound

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