Effect of the composition ratio of pimelic acid/calcium stearate bicomponent nucleator and crystallization temperature on the production of β crystal form in isotactic polypropylene

2007 ◽  
Vol 107 (2) ◽  
pp. 958-965 ◽  
Author(s):  
Qiang Dou
Keyword(s):  
Isotactic Polypropylene ◽  
Crystallization Temperature ◽  
Crystal Form ◽  
Calcium Stearate ◽  
Pimelic Acid ◽  
Composition Ratio ◽  
Effect Of The Composition

scholarly journals Nucleating agents based on graphene and graphene oxide for crystallization of the β-form of isotactic polypropylene

2019 ◽  
Vol 55 (4) ◽  
pp. 1436-1450 ◽  
Author(s):  
Jan Broda ◽  
Marcin Baczek ◽  
Janusz Fabia ◽  
Dorota Binias ◽  
Ryszard Fryczkowski
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Isotactic Polypropylene ◽  
Reduced Form ◽  
Pimelic Acid ◽  
Nucleating Agents ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
Reduced Graphene ◽  
Carboxylic Groups

Abstract During the investigations, functionalization of graphene oxide synthesized using modified Hummers’ method and its reduced form was performed. Mixtures of graphene oxide and reduced graphene oxide with pimelic acid and calcium hydroxide were prepared for functionalization. During the reaction, the molecules of pimelic acid were attached to the surface of graphene sheets. By forming links between the carboxylic groups of pimelic acid and graphene oxide, the durable connection was achieved. The functionalized graphene oxide and the reduced graphene oxide were used as additives in isotactic polypropylene crystallization. The influence of additives on crystallisation in non-isothermal conditions was examined using polarized optical microscopy and differential scanning calorimetry. The effect of the additives on the polypropylene structure was analysed using wide-angle X-ray scattering. For both functionalized compounds, the nucleating ability towards β-form of polypropylene was detected. Both additives showed the increase in the nucleation rate and promotion of growth of the β-form crystals. Nucleation efficiency similar to other nucleating agents used in the crystallization of the β-form of polypropylene was revealed.

scholarly journals Isothermal Crystallization and Rheology Properties of Isotactic Polypropylene/Bacterial Cellulose Composite

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1284 ◽  
Author(s):  
Bo Wang ◽  
Fu-hua Lin ◽  
Xiang-yang Li ◽  
Zhong-wei Zhang ◽  
Xiao-rong Xue ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Storage Modulus ◽  
Isotactic Polypropylene ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Complex Viscosity ◽  
Isothermal Crystallization Kinetics ◽  
Interfacial Compatibility ◽  
And Storage ◽  
Better Than

Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing. Esterification modified BC (CO) and Maleic anhydride grafted polypropylene (MAPP) added as a compatibilizer was both used to improve the interfacial compatibility of the iPP/BC composites. The rheology and isothermal crystallization behavior of the composites was tested and discussed. The result shows that the complex viscosity and storage modulus of the composite significantly increase in the rule iPP, iPP/BC2, iPP/CO2, and M-iPP/BC3, which indicates that the compatibility of the composite increases as this rule. According to the isothermal crystallization kinetics result, the crystal growth mode of iPP was not affected by the addition of BC and the interfacial compatibility. The spherulite growth rate of the iPP/BC composite increases with increasing crystallization temperature. Especially, the value decreases as the same rule with the complex viscosity and storage modulus of the composite at the same isothermal crystallization temperature. These results suggest that the interface compatibility of iPP/BC composites is greatly improved and the interface compatibility of the M-iPP/BC3 is better than the iPP/CO2.

Crystal form and orientation of isotactic polypropylene samples prepared by vibration-injection molding

2007 ◽  
Vol 106 (3) ◽  
pp. 1456-1461 ◽  
Author(s):  
Jie Zhang ◽  
Tai Zeng ◽  
Ji Zhu ◽  
Yanwei Lei ◽  
Kaizhi Shen ◽  
...  
Keyword(s):  
Injection Molding ◽  
Isotactic Polypropylene ◽  
Crystal Form

scholarly journals The Friction of Structurally Modified Isotactic Polypropylene

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7462
Author(s):  
Natalia Wierzbicka ◽  
Tomasz Sterzyński ◽  
Marek Nowicki
Keyword(s):  
Isotactic Polypropylene ◽  
Heterogeneous Nucleation ◽  
Total Content ◽  
Mold Temperature ◽  
Pimelic Acid ◽  
Reciprocating Motion ◽  
Shore Hardness ◽  
Β Phase ◽  
Forming Temperature ◽  
Injection Molded

The purpose of studies was to analyse an impact of heterogeneous nucleation of modified isotactic polypropylene (iPP) on its tribological properties. The iPP injection molded samples, produced by mold temperature of 20 and 70 °C, were modified with compositions of two nucleating agents (NA’s), DMDBS creating α-form and mixture of pimelic acid with calcium stearate (PACS) forming β–phase of iPP, with a total content 0.2 wt.% of NA’s. A polymorphic character of iPP, with both, monoclinic (α) and pseudo-hexagonal (β) crystalline structures, depending on the NA’s ratio, was verified. The morphology observation, DSC, hardness and tribological measurements as test in reciprocating motion with “pin on flat” method, were realized, followed by microscopic observation (confocal and SEM) of the friction patch track. It was found that Shore hardness rises along with DMBDS content, independent on mold temperature. The friction coefficient (COF) depends on NA’s content and forming temperature—for upper mold temperature (70 °C), its value is higher and more divergently related to NA’s composition, what is not the case by 20 °C mold temperature. The height of friction scratches and the width of patch tracks due to its plastic deformation, as detected by confocal microscopy, are related to heterogeneous nucleation modified structure of iPP.

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