Rheological behavior of blends from a linear and a long-chain branched polypropylene

Stange, Jens; Uhl, Claudia; Münstedt, Helmut

doi:10.1122/1.2008297

Cited by 119 publications

(122 citation statements)

References 31 publications

Supporting

Mentioning

117

Contrasting

Order By: Relevance

“…If the sample has been prepared by blending two samples of different types, it is useful to know the blending ratio in addition to the polymerization mechanisms by which the two initial samples were created, so that the ensemble of molecules can potentially be constructed [345]. Once we are able to describe the molecules parametrically (using a few parameters), we can apply molecular models based on the tube theory.…”

Section: Model-driven Data-analysis Methodsmentioning

confidence: 99%

Analytical Rheology of Polymer Melts: State of the Art

Shanbhag

2012

ISRN Materials Science

View full text Add to dashboard Cite

The extreme sensitivity of rheology to the microstructure of polymer melts has prompted the development of "analytical rheology," which seeks inferring the structure and composition of an unknown sample based on rheological measurements. Typically, this involves the inversion of a model, which may be mathematical, computational, or completely empirical. Despite the imperfect state of existing models, analytical rheology remains a practically useful enterprise. I review its successes and failures in inferring the molecular weight distribution of linear polymers and the branching content in branched polymers.

show abstract

Section: Model-driven Data-analysis Methodsmentioning

confidence: 99%

Analytical Rheology of Polymer Melts: State of the Art

Shanbhag

2012

ISRN Materials Science

View full text Add to dashboard Cite

show abstract

“…It was found that the foaming behavior of linear PP could already be improved with respect to higher expansion ratios and reduced cell coalescence by the addition of LCB-PP at contents of 20-30 wt %. 14 The crystallization behavior of crystalline polymers is greatly influenced by the molecular structure and crystallization conditions. LCB-PP exhibits unique crystallization behavior in terms of a shorter crystallization time and varied crystalline morphologies as compared to linear PP.…”

Section: Introductionmentioning

confidence: 99%

Crystallization behavior and crystallization kinetic studies of isotactic polypropylene modified by long‐chain branching polypropylene

Fan

Dong

2009

J of Applied Polymer Sci

View full text Add to dashboard Cite

In this article, we discuss the crystallization behavior and crystallization kinetics of isotactic polypropylene (iPP) modified by long-chain-branching (LCB) high-melt-strength iPP over a wide composition range, that is, LCB-iPP from 10 to 50 wt %. Over the entire range we investigated, the presence of LCB-iPP accelerated crystallization in both the isothermal crystallization process and nonisothermal crystallization process, even when the LCB-iPP content was as low as 10%, and both crystallization processes were enhanced more significantly as the LCB-iPP content increased. Hoffman-Lauritzen theory analysis revealed that the fold-free energy decreased effectively with the occurrence of the LCB structure, although the growth rate of spherulites was depressed, as shown by polarized optical microscopy. Meanwhile, the regime III-regime II transition temperature was about 15higher for all of the LCB-iPP compositions than that of iPP because the LCB structure reduced the mobility of the polypropylene chains. Furthermore, the c-form crystal structure was favored by LCB compared to the b form, which was supported by wide-angle X-ray diffraction.

show abstract

“…Thus, the modified polymer resisted up to the elongational deformation without failure for the complete test durations. Considering the wide polydispersity for the modified PLA, this gives rise to the assumption that the effect of the branching structure on the strain hardening dominates [28,29]. Depending on the number of branches and molecular weight, entanglement density may be increased or decreased by branching.…”

Section: Uniaxial Extensional Experimentsmentioning

confidence: 99%

Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

2015

View full text Add to dashboard Cite

This study was dedicated to the blown film extrusion of poly(lactic acid), which mainly presents poor shear and elongation viscosities, and its blends. In order to enhance its melt strength, two main routes were selected (i) a structural modification through chain extension and branching mechanisms by adding a reactive multifunctional epoxide (named Joncryl) and (ii) blending with poly(butylene adipate-co-terephtalate), named PBAT in presence (or not) of Joncryl. The effects of the reactive agent on the shear and elongation rheology, morphological, and interfacial properties of the blends were systematically investigated. A decrease of the interfacial tension has been also demonstrated according to the deformed drop retraction method (DDRM). Hence, the role of Joncryl as a compatibilizer was highlighted. Consequently, finer morphology of the dispersed phase was obtained. Furthermore, the impact of the two modification routes on the blown film extrusion ability of PLA has been studied. Based on the improved shear and elongational rheological properties, a great enlargement of the blowing processing window of PLA modified with Joncryl was demonstrated. Indeed, with the addition of Joncryl into OPEN ACCESSPolymers 2015, 7 940 PLA-PBAT blends, a reduction of the instability defects has been detected. Finally, the induced crystalline structure and the thermo-mechanical properties of blown films were shown to be improved.

show abstract

Rheological behavior of blends from a linear and a long-chain branched polypropylene

Cited by 119 publications

References 31 publications

Analytical Rheology of Polymer Melts: State of the Art

Analytical Rheology of Polymer Melts: State of the Art

Crystallization behavior and crystallization kinetic studies of isotactic polypropylene modified by long‐chain branching polypropylene

Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

Contact Info

Product

Resources

About