Effect of ?-phase nucleating additives on structure and properties of blow extruded polypropylene

Radhakrishnan, S.; Tapale, M.; Shah, Nouman Ali; Rairkar, E.; Shirodkar, V. S.; Natu, H. P.

doi:10.1002/(sici)1097-4628(19970516)64:7<1247::aid-app1>3.0.co;2-j

Cited by 19 publications

(9 citation statements)

References 2 publications

(2 reference statements)

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“…The transformation is not reversible and occurs in the temperature range of 130–150 °C 34. There have been many investigations into the transformation of trigonal into monoclinic modification in iPP 30, 35. Garbarczyk et al put forward that the essential factors for the occurrence of β → α transiton is heating temperature and heating time.…”

Section: Resultsmentioning

confidence: 99%

“…On the other side, the increasing additive could lead to lower surface area and/or effective number of available sites of nucleation of the particular phase, due to the aggregation of the nucleating agent particles. 21,30 In our experiment, the disappearance of b crystalline form on increasing SB content in the matrix suggests that a nucleation is enhanced with respect to b nucleation when a larger number of SB domains is present in PP/SB blends. In this case, a greater number of a nuclei would be produced at the early stages than at lower SB proportions, and the growing fronts of these a spherulites could enclose other SB domains.…”

Section: Resultsmentioning

confidence: 99%

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Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent

Dong

Guo

et al. 2008

J Polym Sci B Polym Phys

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Sodium benzoate (SB), a conventional nucleating agent of α‐phase isotactic polypropylene (iPP) was discovered to induce the creation of β‐phase iPP under certain crystalline conditions. Polarized optical microscopy (POM) and wide angle X‐ray diffraction (WAXD) were carried out to verify the versatile nucleating activity of SB and investigate the influences of SB's content, isothermal crystallization temperature, and crystallization time on the formation of β‐phase iPP. The current experimental results indicated that, under isothermal crystallization conditions, SB showed peculiar nucleating characteristics on inducing iPP crystallization which were different from those of the commercial β form nucleating agent (TMB‐5). The content of β crystal form of iPP nucleated with SB (PP/SB) increased initially with the increase of crystallization temperature, nucleating agent (SB) percentage or crystallization time, reached a maximum value, and then decreased as the crystallization temperature, nucleating agent percentage or crystallization time further increased. While the content of β crystal form of iPP nucleated with TMB‐5 (PP/TMB‐5) showed a completely different changing pattern with the crystallization conditions. The obvious difference of the two kinds of nucleating agents on inducing iPP crystallization can be explained by the versatile nucleating ability of SB. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1183–1192, 2008

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent

Dong

Guo

et al. 2008

J Polym Sci B Polym Phys

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“…During crystallization in the presence of quinacridone pigment a structure containing a high amount of the β‐modification was observed. By addition of this pigment, films,16, 17 injection moldings,18 and fibers19 with high content of the β‐form were obtained. The nucleating efficiency of other pigments is less known.…”

Section: Introductionmentioning

confidence: 99%

Nucleating activity of the quinacridone and phthalocyanine pigments in polypropylene crystallization

Broda¹

2003

J of Applied Polymer Sci

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ABSTRACT:The nucleating ability of two organic pigments, quinacridone and phthalocyanine, in nonisothermal polypropylene (PP) crystallization was investigated. The investigations were carried out using DSC and polarizing microscopy. The efficiency of pigments in the nucleation process was determined in a simple test comparing the crystallization temperature of the PP-containing pigments with respect to the pure polymer. Both pigments revealed good nucleating activity. In the presence of pigments the increment of the crystallization temperature and the increase of nucleation rate were observed. The nucleating efficiency of pigments was confirmed in investigations of the obtained structure. The nucleating activity of pigments was explained by their features fulfilling several requirements for good nucleating agents.

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“…Of the abovementioned substances, quinacridone pigment is one of the most effective additives 26, 27. Through the addition of quinacridone pigment, injection moldings28–30 and films31–33 with high β‐form contents were obtained.…”

Section: Introductionmentioning

confidence: 99%

Influence of processing on structure of β‐nucleated poly(propylene) fibers

Broda

2003

J of Applied Polymer Sci

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Fibers colored with quinacridone pigment spun at low take-up velocities were obtained. The spun fibers, with a very high ␤-form content, were drawn at room temperature and at a temperature of 120°C at different draw ratios. They were then heat stabilized at different temperatures, ranging from 140 to 150°C for different time intervals. As a result of drawing, the transition from ␤ to mesophase, as well as that from ␤ to ␣, was observed. The ␤ to mesophase transition results from cold drawing at room temperature, while the ␤ to ␣ transition results from drawing at 120°C. In both cases, the significant decrease of ␤-form content occurs at the low draw ratio of 2. At higher draw ratios, the ␤-form content gradually decreases, and at a draw ratio of 7 the ␤-form disappears altogether. As a result of heat stabilization, the ␤ to ␣ transformation was observed. The first change of the ␤-form content was noticed at 140°C. For fibers stabilized at temperatures above 140°C, the decrease of the ␤-form content is more significant and increases with the increase of the stabilization temperature. At 150°C, a rapid drop of the ␤-form content occurs after only 3 min, and after a few more minutes the ␤-form disappears.

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Effect of ?-phase nucleating additives on structure and properties of blow extruded polypropylene

Cited by 19 publications

References 2 publications

Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent

Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent

Nucleating activity of the quinacridone and phthalocyanine pigments in polypropylene crystallization

Influence of processing on structure of β‐nucleated poly(propylene) fibers

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