Chain conformation and average degree of polymerization of the sequences in copolyesters

Olbrich, E.; Chen, D.; Lindner, Peter; Zachmann, H. G.; Benoît, H.

doi:10.1016/0921-4526(89)90694-7

Cited by 3 publications

(2 citation statements)

References 3 publications

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“…The activation energy calculated from this relation is 141.9 kJ mol"1, in fair agreement with that obtained for the lower molecular weight polymer. From the data for the lower molecular weight polymer reported here, we obtained k = 1.48 X 1014 exp(-20.90 X 103/T) (9) Evidently, the rate constant for the transesterification reaction of the higher molecular weight LCP is considerably smaller than that for the low molecular weight polymer. The dependence of the two rate constants on the reaction temperature calculated from eqs 8 and 9 is shown in Figure 5.…”

Section: Resultsmentioning

confidence: 56%

A neutron scattering investigation of the transesterification of a main-chain aromatic polyester

MacDonald¹,

McLenaghan²,

Mclean³

et al. 1991

Macromolecules

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Section: Resultsmentioning

confidence: 56%

A neutron scattering investigation of the transesterification of a main-chain aromatic polyester

MacDonald¹,

McLenaghan²,

Mclean³

et al. 1991

Macromolecules

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“…They are given by the sum of the degrees of polymerization of all PET blocks ^pphb, respectively. This yields an average b value (b2) = (h2)/ = Xpet52pet "* (1 -Xpet)52phb (12) where xpEt is the mole fraction of PET given by npet/n and = mpet + ß is the average degree of polymerization of the copolyester. As &phb obviously has to be larger than ¿>pet> eq 11 leads to a monotonic increase of (b2) with increasing PHB content.…”

Section: Resultsmentioning

confidence: 99%

Chain conformations in copolyesters of poly(ethylene terephthalate) and poly(p-hydroxybenzoic acid) as determined by small-angle neutron scattering

Olbrich¹,

Chen²,

Zachmann³

et al. 1991

Macromolecules

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Small-angle neutron scattering (SANS) experiments were performed on blends of deuterated and nondeuterated copolyesters of poly(ethy1ene terephthalate) (PET) and poly@-hydroxybenzoic acid) (PHB). The PET content varied between 80 and 60 mol % , the sample containing 60 mol ' ?6 being liquid crystalline. Depending on the time of melting during sample preparation, transesterification took place to various degrees resulting in samples in which the molecules contained deuterated and nondeuterated blocks of various lengths. The average degree of polymerization and radius of gyration of these blocks were measured and the length of the statistical element b was calculated as a function of composition. The transition from the amorphous to the liquid-crystalline state did not lead to an additional increase in b. From this it was concluded that, in the nematic state, the molecules are not elongated. From the length of the statistical element, the average degree of polymerization of the PHB sequences could be estimated.

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Theory of Markov chain copolymerization in terms of an intermonomer correlation coefficient and the arrangement of monomers along the polymer chain

Stribeck

1992

Polymer

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Chain conformation and average degree of polymerization of the sequences in copolyesters

Cited by 3 publications

References 3 publications

A neutron scattering investigation of the transesterification of a main-chain aromatic polyester

A neutron scattering investigation of the transesterification of a main-chain aromatic polyester

Chain conformations in copolyesters of poly(ethylene terephthalate) and poly(p-hydroxybenzoic acid) as determined by small-angle neutron scattering

Theory of Markov chain copolymerization in terms of an intermonomer correlation coefficient and the arrangement of monomers along the polymer chain

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