Polypropylene random copolymer in pipe application: Performance improvement with controlled molecular weight distribution

Yu, Lei; Wu, Tong; Tian, Chen; Yang, Feng; Xiang, Ming

doi:10.1016/j.tca.2013.11.009

Cited by 27 publications

(25 citation statements)

References 59 publications

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“…The reason was that the GF in matrix accelerated the molecular chain movement at low frequency but was obstacle to the movement at high frequency. Overall, the viscosities of 20 and 40 wt % GF reinforced PPR did not appear much difference from that of pure PPR and all of them had good processability …”

Section: Resultsmentioning

confidence: 88%

The influence of hoop shear field on the structure and performances of glass fiber reinforced three‐layer polypropylene random copolymer pipe

Deng

Jin

Zhao

et al. 2018

J of Applied Polymer Sci

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Three-layer pipe has many advantages over single layer one, especially for the pipe of glass fiber (GF) reinforced materials. But the hoop strength of the pipe produced via convention extrusion is poor because GFs orient along axial direction. In this work, a self-designed rotation extrusion system was adopted to extrude GF reinforced three-layer polypropylene random copolymer (PPR) pipe, in which a hoop shear field was applied to the polymer matrix and fibers in the middle layer. The structure and performance of pipes were investigated via scanning electronic microscope (SEM) and synchrotron two-dimensional wide-angel X-ray diffraction (2D-WAXD). Due to the hoop shear field, the orientation of GFs in middle layer deviated from axial direction. As a result, PPR pipes with enhanced hoop tensile strength were obtained. Because of the three-layer structure and the production process, the molecular chains of middle layer did not emerge distinct orientation after rotation shear, as shown in 2D-WAXD and SEM experimental results. This three-layer pipe rotation extrusion system offers a novel method for the modification of pipes in manufacture industry.

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Section: Resultsmentioning

confidence: 88%

The influence of hoop shear field on the structure and performances of glass fiber reinforced three‐layer polypropylene random copolymer pipe

Deng

Jin

Zhao

et al. 2018

J of Applied Polymer Sci

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“…According to the standard ISO 15874, the high-performance pipe material class PP-RCT is defined as a polypropylene random copolymer with distinct crystalline morphology and improved pressure and temperature resistance, allowing for the production of pipes for higher pressures or with thinner wall thicknesses at constant loads [2,3]. Indeed, beta-nucleated PP-R with its trigonal β crystal form and its fine spherulite structure is classified as PP-RCT material, and it is recommended for pressure pipes in hot water circulation systems and for other applications where materials with excellent impact strength, chemical resistance and crack growth resistance are required [1,4,5,6,7,8,9].…”

Section: Introductionmentioning

confidence: 99%

Chlorinated Water Induced Aging of Pipe Grade Polypropylene Random Copolymers

et al. 2019

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Polypropylene random copolymers (PP-R) are common materials for pressurized hot water pipes. In many pipe systems, potable water is disinfected by chlorine to prevent waterborne diseases. This paper deals with hot chlorinated water induced aging of two PP-R grades with varying morphology. One material had a conventional monoclinic α crystal form (PP-Rα), whereas the other was explicitly beta-nucleated resulting in a trigonal β crystal form with a fine spherulite structure (PP-Rβ). Micro-sized specimens with a thickness of 100 µm were used for aging experiments at 60 °C in chlorinated water with 5 mg/L free chlorine, and aging indicators were monitored for exposure times of up to 2000 h. On the other hand, superimposed mechanical-environmental tests were carried out by using cracked round bar specimens with a diameter of 14 mm to determine the fatigue crack growth (FCG) resistance of both PP-R grades at 60 °C in non-chlorinated and chlorinated water. PP-Rβ was found to outperform PP-Rα with an about 30% higher time-to-embrittlement value of 2000 h. Furthermore, PP-Rβ exhibited an enhanced FCG resistance in both non-chlorinated and chlorinated water. The effect of chlorine content on the deterioration of the FCG resistances was significantly more pronounced for PP-Rα.

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“…However, the low‐temperature impact toughness of PPR still needs to be improved. On the other hand, the processability and mechanical properties of PPR can be enhanced simultaneously by the broadening of the molecular weight (MW) distribution . Yu et al .…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, the processability and mechanical properties of PPR can be enhanced simultaneously by the broadening of the molecular weight (MW) distribution . Yu et al . found that through the fine broadening of the MW distribution, the tensile strength of PPR obviously increased, but the impact toughness improved slightly.…”

Section: Introductionmentioning

confidence: 99%

Dynamic mechanical properties, crystallization behaviors, and low‐temperature performance of polypropylene random copolymer composites

Yin

Wang

Zhang

et al. 2015

J of Applied Polymer Sci

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In this study, polypropylene random copolymer (PPR) composites were prepared by the addition of either three kinds of thermoplastic rubber (TPR) modifiers (types 2088A, 2095, and 2096) or an ethylene-octene copolymer (POE)/high-density polyethylene (HDPE; 2 :1 w/w) blend. Differential scanning calorimetry, wide-angle X-ray diffraction, and dynamic mechanical analysis were used to characterize the crystallization behaviors and dynamic mechanical properties of the PPR composites. The results indicated that PPR/POE/HDPE and PPR/TPR2088A had better comprehensive mechanical properties, especially the low-temperature toughness among all of the samples. The obtained PPR/POE/HDPE blends showed a high toughness and good stiffness in the temperature interval from 210 to 238C with the addition of only 10 wt % POE/HDPE. When the temperature continued to fall below 2108C, the PPR/TPR2088A composites exhibited a better impact toughness without a loss of too much stiffness. The good low-temperature toughness of those two composites was attributed to both the decrease in the crystallinity and the uniform dispersion, obvious interfacial adhesion, and cavitation ability of POE/HDPE and TPR2088A in the PPR matrix.

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Polypropylene random copolymer in pipe application: Performance improvement with controlled molecular weight distribution

Cited by 27 publications

References 59 publications

The influence of hoop shear field on the structure and performances of glass fiber reinforced three‐layer polypropylene random copolymer pipe

The influence of hoop shear field on the structure and performances of glass fiber reinforced three‐layer polypropylene random copolymer pipe

Chlorinated Water Induced Aging of Pipe Grade Polypropylene Random Copolymers

Dynamic mechanical properties, crystallization behaviors, and low‐temperature performance of polypropylene random copolymer composites

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