Influence of nucleants on the formation of shear-induced structures in polypropylene

Gahleitner, Markus; Wolfschwenger, Johannes; Fiebig, Joachim; Neißl, Wolfgang

doi:10.1002/1521-3900(200208)185:1<77::aid-masy77>3.0.co;2-w

Cited by 11 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7(b)], which shows that higher shear rate causes more molecular chain orientation and increases the amount of thread-like crystal. This phenomenon was also observed by Gahleitner et al 25 and Wang et al 26 in other semicrystalline polymers like PE when subjected to shear flow. Based on our results, we suggest that the higher melting peak is correlated with the formation of thread-like structures.…”

Section: Thermal Melting Behavior Of Pps After Shearsupporting

confidence: 80%

“…A great effort1, 7, 21–29 has been made to study the role of higher molecular weight or longer molecular chains in the shear induced crystallization of polymers, and has suggested that the longer molecular chains can greatly accelerate the formation of shish‐kebab structures under shear. More recently, Kimata et al,30 Housmans et al31 and Zhao and coworkers32, 33 suggested that the shish structure consists of both long‐ and short molecular chains.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effect of molecular weight on crystallization of semirigid poly(phenylene sulfide) under shear flow

Zhang

2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

Isothermal crystallization of poly(phenylene sulfide) with three molecular weights (M w ¼ 22k, 48k, and 52k, respectively) under shear condition has been investigated. It appears that shear can induce all these three PPS samples to form a thread-like crystal structure which consists of the numerous stable nuclei that align tightly in the direction of shear. Crystallization kinetics of PPS has been greatly influenced by shear flow. Higher shear rate and long shear time can lead to decrease of spherulite growth rate of PPS. Also, the spherulite growth rate of PPS is affected by supercoolings and molecular weight. For the lower molecular weight (M w ¼ 22k), the spherulite growth rate is independent on the shear rate and shear time; while for the higher ones (M w ¼ 48k and 52k), with the increasing of shear rate, the spherulite growth rate of PPS increases to reach maximum at first, and then decreases. The lower the crystallization temperature is, the more the spherulite growth rate changes, showing that higher orientation of molecular chains can be obtained more easily with increased supercooling. A model has been proposed to explain the mechanism of thread-like crystal formation under shear flow.

show abstract

Section: Thermal Melting Behavior Of Pps After Shearsupporting

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Effect of molecular weight on crystallization of semirigid poly(phenylene sulfide) under shear flow

Zhang

2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Moreover, the higher main melting peak intensity increases with the shear rate, which shows that higher shear rate causes more molecular chains' orientation and increases the amount of shish-kebab-like fibrillar crystal. This phenomenon was also observed by Gahleitner et al [71] and Hsiao et al [46] in other semicrystalline polymers like PE when subjected to shear flow. They proposed that the shear-induced shish-kebab precursor consisted of macrokebabs and microkebabs, and the outer macrokebabs melt first and then the inner microkebabs when the temperature was increased.…”

Section: Melting Behavior Of Fibrillar Crystalsmentioning

confidence: 99%

Shear-induced crystallization of poly(phenylene sulfide)

Zhang

et al. 2008

Polymer

View full text Add to dashboard Cite

“…As to morphology, many studies concerning the influence of (intense) flow on nucleated polymers suggest that particles enhance the orienting effect of shear to a certain extent 21, 28–30, 33–37. The extent of this “synergistic” effect may be linked with the intensity of the contact between the particles and their matrix 38.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Calcium‐Stearate‐Coated Calcium Carbonate and Talc on the Quiescent and Flow‐Induced Crystallization of Isotactic Poly(propylene)

D’Haese

Goderis

Puyvelde

2011

Macro Materials & Eng

View full text Add to dashboard Cite

The influence of Ca‐stearate‐coated CaCO3 and talc on the quiescent and flow‐induced crystallization of iPP is studied using different methods. Comparison of rheometry and DSC shows that rheometry is an interesting tool to monitor crystallization kinetics. It is observed that the Ca‐stearate coating degrades at commonly used annealing temperatures, influencing the crystallization behavior of the CaCO3‐containing polymer. WAXD indicates that the CaCO3 does not significantly influence the degree of crystallinity. As shear intensifies, both the pure and particle‐containing polymers crystallize faster; however, their behavior also becomes increasingly similar. There are indications that shear influences the organization of the CaCO3 aggregates. magnified image

show abstract

Influence of nucleants on the formation of shear-induced structures in polypropylene

Cited by 11 publications

References 0 publications

Effect of molecular weight on crystallization of semirigid poly(phenylene sulfide) under shear flow

Effect of molecular weight on crystallization of semirigid poly(phenylene sulfide) under shear flow

Shear-induced crystallization of poly(phenylene sulfide)

The Influence of Calcium‐Stearate‐Coated Calcium Carbonate and Talc on the Quiescent and Flow‐Induced Crystallization of Isotactic Poly(propylene)

Contact Info

Product

Resources

About