Peroxydicarbonate modification of polypropylene and extensional flow properties

Lagendijk, R.P; Hogt, A.H.; Buijtenhuijs, Ab; Gotsis, A. D.

doi:10.1016/s0032-3861(01)00553-5

Cited by 157 publications

(148 citation statements)

References 11 publications

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“…Similar behavior have been already reported for investigating sparsely LCB-PE [Wang et al (2004)], polypropylene featuring low amounts of LCB [Lagendijk et al (2001); Auhl et al (2004)], and for LCB metalocene catalyzed PE (which is a blend of linear and branched chains) ]. Authors concluded that this technique was not enough sensitive to estimate slight changes in molecular dimensions between the very low amount of nonuniform branched structures and the dominant linear fraction.…”

Section: A Mw Characterizationsupporting

confidence: 80%

Using viscoelastic properties to quantitatively estimate the amount of modified poly(lactic acid) chains through reactive extrusion

Cailloux¹,

Santana²,

Maspoch³

et al. 2015

Journal of Rheology

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In this study, the dynamic viscoelastic properties of three structurally modified poly(lactic acid) (PLA) samples processed through reactive extrusion (REX) were analyzed. While classical chromatographic and spectroscopic techniques exhibited limited sensitivity to the presence of topological changes, rheological measurements confirmed the presence of nonuniform branched macromolecules, holding sparsely long chain branches. According to the processing conditions used, the flow activation energy and the thermorheologically simple behavior remained roughly unaffected for PLA-REX containing an amount of modified chains up to 24%. Distinctly separated relaxation processes in a broader transition zone were observed in the complex viscosity function (jg*(x)j) of all PLA-REX samples. The "extended Carreau-Yassuda" model and an extension of the Havriliak-Negami model, proposed in this work, were used to capture the main characteristics of jg*(x)j experimental data. Both fitted models were inverted to molecular weight distribution (MWD) spectrum using the numerical inversion technique of Shaw and Tuminello, and these were compared with size exclusion chromatography MWDs. It was shown that the resolution of the predicted bimodal MWDs was enhanced when the model used to fit jg*(x)j data was exempted from the Cox-Merz rule and included a complex time dependence.

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Section: A Mw Characterizationsupporting

confidence: 80%

Using viscoelastic properties to quantitatively estimate the amount of modified poly(lactic acid) chains through reactive extrusion

Cailloux¹,

Santana²,

Maspoch³

et al. 2015

Journal of Rheology

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“…This relation, however, is not very sensitive to small values of B n [1] and the method is not quantitative in this case.…”

Section: Measuring the Level Of Lcbmentioning

confidence: 87%

“…Because a branched chain is more compact in a solvent than a linear chain with the same molecular mass, the intrinsic viscosity of a branched polymer is lower than the one of the equivalent linear polymer. Therefore, if the intrinsic viscosity of the fractions is measured as they come out of the column, then LCB can also be inferred by GPC [1]. For this reason different sensors (usually three) are used simultaneously at the eluent to determine independently the molecular weight and the intrinsic viscosity of the fractions.…”

Section: Measuring the Level Of Lcbmentioning

confidence: 99%

“…However, the most efficient way to enhance the melt strength of polymers with linear chains is by grafting long chain branches (LCB) on them. It is expected that the position of iPP in the plastics market will become even more prominent if the elongational flow behaviour of its melt is improved [1].…”

Section: Introductionmentioning

confidence: 99%

“…These are mostly produced by grafting long chain branches on the PP linear backbone, either by electron beam (EB) irradiation [2] or in the melt by using peroxides with relative low decomposition temperature [1]. These methods produce LCB-PP with broadened molecular weight distribution and complex branch structures.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Long chain branching on linear polypropylene by solid state reactions

Borsig

Duin

Gotsis

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Polymer Cross‐Linkling

Ray

2011

Encyclopedia of Polymer Science and Technology

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Cross‐linking is a unique tool for polymer modification. Multidirectional chain extension of polymers resulting in the formation of network structure is defined as polymer cross‐linking. It hinders the free movement of polymer chains and restricts them from sliding past each other. Interconnection of the polymer chains generates elasticity in amorphous polymers and makes a polymer more resistant to heat, light, and other physical agencies. It enhances the dimensional stability, mechanical strength, and solvent resistance of a polymer. Cross‐linking may be accomplished either through polymerization of monomers with functionality greater than two (polycondensation) or by covalent bonding between preformed polymer molecules by irradiation, sulfur vulcanization, or miscellaneous chemical reactions. The degree of cross‐linking and regularity of the network are the two vital factors, which control the effects of cross‐linking on the properties of the polymers. Cross‐linking is carried out in elastomers, plastomers, and even on polymer blends to improve properties and to broaden the spectrum of applications. The present review describes different modes and kinetics of polymer cross‐linking as well as its effects on the properties of polymers.

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Peroxydicarbonate modification of polypropylene and extensional flow properties

Cited by 157 publications

References 11 publications

Using viscoelastic properties to quantitatively estimate the amount of modified poly(lactic acid) chains through reactive extrusion

Using viscoelastic properties to quantitatively estimate the amount of modified poly(lactic acid) chains through reactive extrusion

Long chain branching on linear polypropylene by solid state reactions

Polymer Cross‐Linkling

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