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An effective a/b nucleating agent compoundfor the preparation of polypropylene / M. Dong in INTERNATIONAL POLYMER PROCESSING, Vol. XXXIII, N° 2 (05/2018)
[article]
Titre : An effective a/b nucleating agent compoundfor the preparation of polypropylene Type de document : texte imprimé Auteurs : M. Dong, Auteur ; Y. H. Xu, Auteur ; S. J. Zhang, Auteur ; Y. Lv, Auteur ; Y. Q. Bai, Auteur ; R. S. Chen, Auteur Année de publication : 2018 Article en page(s) : p. 164-170 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agent de nucléation
Cristallisation
Matières plastiques -- Propriétés mécaniques
Nucléation
PolypropylèneIndex. décimale : 668.4 Plastiques, vinyles Résumé : The crystallization behavior and mechanical properties were investigated by mixing the traditional α-form nucleating agent (sodium benzoate, SB) and commercialized β-form nucleating agent (TMB-5) in isotactic polypropylene (iPP). Mechanical properties were evaluated by universal testing machines. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were conducted to illustrate the crystallization behavior. Polarized optical microscopy (POM) was adopted to observe the crystal morphologies. The experimental results show that the weight ratio of two types of nucleating agents determines the final crystal structure and mechanical properties of iPP. When the weight ratio of [SB] : [TMB-5] is 4 : 1, the impact strength and flexural modulus of iPP reach a maximum value. Compared with the single component β-form nucleating agent, the compound nucleating agent exhibits significant synergistic effect and shows better mechanical properties. It is expected that this new nucleation system will have potential industrial applications. Note de contenu : - EXPERIMENTAL SECTION : Materials - Samples preparation - Characterization
- RESULTS AND DISCUSSION : Mechanical properties - Crystallization behavior - Crystalline morphologyDOI : 10.3139/217.3361 En ligne : https://drive.google.com/file/d/131Co1Duh22COhEIChTAQQueUxrwiRSva/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30564
in INTERNATIONAL POLYMER PROCESSING > Vol. XXXIII, N° 2 (05/2018) . - p. 164-170[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 19873 - Périodique Bibliothèque principale Documentaires Disponible Influence of crystal structure on thermo-mechanical properties of injection molded B-nucleated iPP / A. Hamza in INTERNATIONAL POLYMER PROCESSING, Vol. 36, N° 5 (2021)
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Titre : Influence of crystal structure on thermo-mechanical properties of injection molded B-nucleated iPP Type de document : texte imprimé Auteurs : A. Hamza, Auteur ; R. K. Arya, Auteur ; A. D. Palsodkar, Auteur ; G. R. Bhadu, Auteur ; S. J. A. Rizvi, Auteur Année de publication : 2021 Article en page(s) : p. 545-556 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agent de nucléation
Caractérisation
Matériaux -- Propriétés thermomécaniques
Matières plastiques
Matières plastiques -- Moulage par injection
Mélange
Polymères -- Propriétés thermomécaniques
Polymères isotactiques
Polypropylène greffé anhydride maléique
Structure cristalline (solide)
Thermodurcissables -- Propriétés thermomécaniquesIndex. décimale : 668.4 Plastiques, vinyles Résumé : Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent. Note de contenu : - EXPERIMENTAL : Materials - Melt compounding - Injection molding - Testing of molded specimens
- RESULTS AND DISCUSSION : Effect of concentration of β-nucleator on thermo-mechanical properties of iPP - Effect of coupling agent (PP-g-ma) on the efficiency of β-nucleator - Stretching induced (β-α) transformation in β-iPP
- Table 1 : Injection molding parameters
- Table 2 : Crystallinity of neat and 𝛽-iPP at different concentrations of 𝛃-nucleator (calculated from WAXD data)
- Table 3 : Crystallinity of neat- and 𝛃-iPP at different concentrations of 𝛃-nucleator (calculated from DSC first heating data)
- Table 4 : Results of DSC second heating scan for neat and 𝛃-nucleated iPP
- Table 5 : Crystallinity values of 𝛃-iPP with different concentration (wt.%) of PP-g-MA
- Table 6 : DSC-second melting and crystallization parameters for 𝛃-nucleated iPP containing coupling agent (PP-g-MA)
- Table 7 : Effect of stretching on crystallinity and crystal structureDOI : https://doi.org/10.1515/ipp-2020-4106 En ligne : https://drive.google.com/file/d/1fBkbI5UTQhKXftRExRvGTPuJb7sNbvIl/view?usp=shari [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=36521
in INTERNATIONAL POLYMER PROCESSING > Vol. 36, N° 5 (2021) . - p. 545-556[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 23735 - Périodique Bibliothèque principale Documentaires Disponible