A WAXS/SAXS study on the deformation behavior of β-nucleated propylene–ethylene random copolymer subjected to uniaxial stretching

Zhang, Chunbo; Liu, Guoming; Jiang, Qianhong; Yang, Jian; Zhao, Ying; Wang, Dujin

doi:10.1039/c5ra04952k

Cited by 19 publications

(16 citation statements)

References 61 publications

(133 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There exist some exceptions where slight cavitations occur without whitening. These exceptions refer to the cavities generated in the samples with thinner lamellae or deformed at high temperature . Therefore, the techniques of USAXS, atomic force microscopy (AFM), and scanning electron microscopy (SEM) become necessary for determining the occurrence of cavities in these cases.…”

Section: Macroscopic Phenomena Of Cavitation‐induced Stress Whiteningmentioning

confidence: 99%

Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers

Men

2018

Macro Materials & Eng

View full text Add to dashboard Cite

Cavitation‐induced stress whitening in semi‐crystalline polymers during stretching significantly influences the physical properties of the materials. This review summarizes studies focusing on two different cavitation processes triggered at small and large strain regimes. The corresponding mechanisms of these two cavitation processes are discussed. For cavitation activated at small strain, there are two basic but distinctly different models with the initiation of cavities either in the amorphous phase or in the crystalline skeleton. For the cavitation triggered at a large strain regime, there are also two different arguments being either due to the defects located in the ends of micro‐fibrils or as a consequence of the fragmentation of load‐bearing inter‐fibril/micro‐fibril tie chains in highly oriented amorphous networks. A unified understanding of the cavitation processes during stretching semi‐crystalline polymers based on interpenetrated network model is proposed. Finally, this review outlooks future research topics for better understanding the cavitation mechanism to meet the industrial need.

show abstract

Section: Macroscopic Phenomena Of Cavitation‐induced Stress Whiteningmentioning

confidence: 99%

Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers

Men

2018

Macro Materials & Eng

View full text Add to dashboard Cite

show abstract

“…A number of reports have covered the influence of the β‐NA content on the mechanical properties of iPP and PPR . However, the quantitative correlation between the mechanical properties and β‐crystal content of PPR has not been established.…”

Section: Introductionmentioning

confidence: 99%

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Zhang

Liu

Jiang

et al. 2015

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Propylene‐based propylene–ethylene random copolymer (PPR) has been widely used in the production of hot‐water pipes. To further improve its toughness and thermal resistance, β‐nucleating agents (β‐NAs) are frequently incorporated. In this study, PPR containing 5.6 mol % ethylene units was modified by two kinds of β‐NAs, that is, calcium pimelate and N,N′‐dicyclohexylterephthalamide. The notched Izod impact strength of PPR increased with the addition of the β‐NAs. Drastically different toughening effects were found between the two β‐NAs. The structure of PPR with and without a β‐NA was investigated by calorimetry, X‐ray diffraction, and thermomechanical analysis. The results indicated that the relative fraction of β crystals (kβ) in the injection‐molded specimens was determined by the type and content of β‐NA. The relationship between kβ and the impact toughness was summarized. A critical value for kβ (0.68) was identified for the brittle–ductile transition of PPR. PPR with β‐NA having a kβ greater than 0.68 displayed a higher impact strength than the other mixtures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42930.

show abstract

“…. For CIM‐PPR, the orientation degrees of α crystal in the outer layers are apparently higher than that in the core region (0 and 1 mm), which is due to the stronger shear and faster cooling rate experienced in the outer layers . It is interesting that the orientation degree of α crystal is increased upon addition of 0.1 wt% Ca‐Pim, especially for the location of 4.5 mm, which is deduced from the narrower length of the diffraction arcs in Fig.…”

Section: Resultsmentioning

confidence: 85%

“…Polypropylene random copolymer (PPR) is prepared by copolymerization of propylene and α‐olefin. Compared with isotactic polypropylene homopolymer (iPP), the crystallizability of PPR is reduced due to the lower isotacticity with the incorporation of comonomers in the molecular chain; correspondingly its toughness is improved . Similar to iPP, PPR can also crystallize in three crystal forms, namely the monoclinic α‐form, the trigonal β‐form and the orthorhombic γ‐form, depending on the crystallization conditions such as crystallization temperature, shear strength, nucleating agent and cooling rate.…”

Section: Introductionmentioning

confidence: 99%

Synergistic enhancement of crystallization and mechanical performance of polypropylene random copolymer by strong shear and β‐nucleating agent

Zhang

Zhao

et al. 2017

Polymer International

Self Cite

View full text Add to dashboard Cite

Investigation of microstructure and properties is critical for the development and application of polymer materials. Polypropylene random copolymer (PPR) and -nucleated PPR are widely used in water pipe production. The effect of melt shear flow on the crystalline structure and mechanical properties of PPR containing -nucleating agent needs in-depth understanding. In this paper, we demonstrated the preparation of PPR and PPR containing 0.1 wt% calcium pimelate (Ca-Pim) samples by conventional injection molding (CIM) and oscillation shear injection molding (OSIM). The multilayer structures and morphologies of the samples were characterized by SEM, two-dimensional X-ray scattering and DSC. The mechanical properties and the microstructures of samples prepared by these two injection molding methods were compared. Compared with samples prepared by CIM, the stronger shear provided by OSIM induced the formation of a thicker layer of a shish-kebab structure and a higher content of crystals, and dramatically suppressed the -nucleating effect of Ca-Pim. The OSIM samples have more shish-kebab structures and higher crystallinities than CIM samples and therefore the former exhibit better rigidity than the latter. The crystals in the core layer and the thicker layer of shish-kebab structure endow OSIM-PPR/0.1 wt% Ca-Pim with excellent impact toughness.

show abstract

A WAXS/SAXS study on the deformation behavior of β-nucleated propylene–ethylene random copolymer subjected to uniaxial stretching

Cited by 19 publications

References 61 publications

Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers

Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Synergistic enhancement of crystallization and mechanical performance of polypropylene random copolymer by strong shear and β‐nucleating agent

Contact Info

Product

Resources

About