Titre : |
Influence of crystal structure on thermo-mechanical properties of injection molded 𝛃-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 thermomécaniques
|
Index. 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 structure |
DOI : |
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 : |
Pdf |
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