Crystallization characteristics of polypropylene and low ethylene content polypropylene copolymer with and without nucleating agents

Zhang, Ruiyun; Zheng, Haifeng; Lou, Xiaolie; Ma, Dezhu

doi:10.1002/app.1994.070510106

Cited by 87 publications

(47 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values of b are larger than 1, which mean that the Avrami exponent n is always slight greater than the Ozawa exponent, m, as it has also been reported in literature. 36,37 Nucleation Activity…”

Section: Mo's Analysismentioning

confidence: 99%

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

Chen

2007

Polym J

View full text Add to dashboard Cite

ABSTRACT:A novel method was employed to modify the surface of carbon black (CB) by organic small molecules in a Haake Rheomix mixer. The investigations of Thermo Gravimetric Analysis (TGA), transmission electron microscopy (TEM), Flourier Transform Infrared spectroscopy (FT-IR) and X-ray Photoelectronic Spectroscopy (XPS) indicated that organic small molecules were grafted onto the surface of MCB and the particle size of MCB was reduced notably. Then the crystallization behavior of polypropylene (PP)/MCB composite as well as pure PP and PP/CB composite were investigated via differential scanning calorimeter (DSC), wide angle X-ray diffraction (WAXD) and optical polarizing microscope (POM). It was found that both CB and MCB can influence the crystallization behavior of PP and provide nucleation sites to the matrix. However, MCB accelerated the crystallization rate and increased the crystallization peak temperature of PP more evidently than CB did. In the case of non-isothermal crystallization, Jeziorny and Mo Equations were used to analyze the data of DSC and both could describe these systems. Finally, the nucleation activity of MCB was evaluated. It was proved that the nucleation activity of MCB was higher than that of CB at the same concentration.

show abstract

Section: Mo's Analysismentioning

confidence: 99%

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

Chen

2007

Polym J

View full text Add to dashboard Cite

show abstract

“…These observations are in good agreement with the characteristics of this compound, which has 16% of EPR phase 19 , dispersed in a polypropylene homopolymer matrix. The presence of the nucleating agent in one of the copolymers, PPcn, reduces the average spherulite size 20 , which tend to increases its impact strength in comparison with the unnucleated PPc 6 . Upon reducing the temperature the impact strength of the blends drops and the addition of up to 25% of elastomer has very little effect on the data.…”

Section: Izod Impact Strengthmentioning

confidence: 99%

Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer

2000

View full text Add to dashboard Cite

The effect of incorporating (C2-C8) ethylene-octene elastomer on the mechanical properties and morphology of polypropylene copolymers has been investigated employing two types of PP copolymer, with and without nucleating agent. The results were compared to the ones presented by a commercial PP heterophase (reactor impact modified PP/EPR). The addition of the elastomer increases the toughness of the blends but reduces their stiffness. PP blends in the low elastomer content region (< 20%) show low values of the Izod impact strength and both, elastomer content and impact strength, are directly proportional to the area under the β damping peak or its maximum intensity of the elastomer. The morphology is a continuous pattern of segregate elastomeric particles with average particle size in the range of 0.27 µm to 0.39 µm. The average particle size and particle size distribution plotted in log-normal distribution curves, increases slightly with the increase in the elastomer content. The reactor modified PP heterophase has a broader particle size distribution and an average particle size of 0.56 µm, at the lower limit but inside the range for good impact performance, as observed.

show abstract

“…The respective influence of nucleating agents (α or β) on the mechanical performances of heterophasic systems composed of an iPP matrix and an ethylene-propylene rubber (EPR) is still controversial, consequence of a lack of published experimental data. Whereas several studies have reported positive effects of nucleation on the fracture resistance of iPP/EPR blends [6][7][8][9][10][11][12], other contributions showed limited (for β-nucleation) [4,[13][14][15][16] or even negative (for α-nucleating agents) ones [4,17,18]. The goal of the present investigation was to identify potential coupling effect between the matrix crystalline structure induced by nucleation and the morphology of the rubbery phase in order to clarify this apparent contradiction.…”

Section: Introductionmentioning

confidence: 99%

On the influence of nucleation on the toughness of iPP/EPR blends with different rubber molecular architectures

Grein¹,

Gahleitner²

2008

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. The influence of α-and β-nucleating agents on the fracture performance of two different 32 wt% rubber modified isotactic Polypropylene (iPP) reactor blends is discussed as a function of the phase morphology of the investigated systems. Nucleation for systems with a large inter-particle distance was found to have only a limited impact on the temperature at which the ductile-brittle transition occurs, negative for α-nucleated blends, almost negligible for β-nucleated resins. For blends exhibiting a small inter-particular distance between their ethylene-propylene rubber (EPR) phase, toughness was promoted slightly by α-nucleation and to a large extent by β-nucleation as compared to a non-nucleated reference. These findings raise the importance of mechanistic synergies between the rubbery phase and the matrix to maximize the fracture resistance of blends.

show abstract

Crystallization characteristics of polypropylene and low ethylene content polypropylene copolymer with and without nucleating agents

Cited by 87 publications

References 17 publications

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer

On the influence of nucleation on the toughness of iPP/EPR blends with different rubber molecular architectures

Contact Info

Product

Resources

About