Polyamide 6 (PA6) suffers from fast degradation in humid conditions due to hydrolysis of amide bonds, which limits its durability. The addition of nanotubular fillers represents a viable strategy for overcoming this issue, although the additive/polymer interface at high filler content can become privileged site for moisture accumulation. As a cost-effective and versatile material, halloysite nanotubes (HNT) were investigated to prepare PA6 nanocomposites with very low loadings (1-45% w/w). The roles of the physicochemical properties of two differently sourced HNT, of filler functionalization with (3-aminopropyl)triethoxysilane and of dispersion techniques (in situ polymerization vs. melt blending) were investigated. The aspect ratio (5 vs. 15) and surface charge (-31 vs.-59 mV) of the two HNT proved crucial in determining their distribution within the polymer matrix. In situ polymerization of functionalized HNT leads to enclosed and well-penetrated filler within the polymer matrix. PA6 nanocomposites crystal growth and nucleation type were studied according to Avrami theory, as well as the formation of different crystalline structures (α and γ forms). After 1680 h of ageing, functionalized HNT reduced the diffusion of water into polymer, lowering water uptake after 600 h up to 90%, increasing the materials durability also regarding molecular weights and rheological behavior.
PA6 and halloysite nanotubes composites with improved hydrothermal ageing resistance : role of filler physicochemical properties, functionalization and dispersion technique / V. Sabatini, T. Taroni, R. Rampazzo, M. Bompieri, D. Maggioni, D. Meroni, M.A. Ortenzi, S. Ardizzone. - In: POLYMERS. - ISSN 2073-4360. - 12:1(2020 Jan), pp. 211.1-211.19.
|Titolo:||PA6 and halloysite nanotubes composites with improved hydrothermal ageing resistance : role of filler physicochemical properties, functionalization and dispersion technique|
SABATINI, VALENTINA (Primo) (Corresponding)
TARONI, TOMMASO TANCREDI ALESSANDRO (Secondo)
ORTENZI, MARCO ALDO (Penultimo)
ARDIZZONE, SILVIA (Ultimo)
|Parole Chiave:||Functionalizing agent; Halloysite nanotube; Hydrothermal ageing; In situ polymerization; Melt blending; Nanocomposite; Polyamide 6; Polymorphism|
|Settore Scientifico Disciplinare:||Settore CHIM/04 - Chimica Industriale|
Settore CHIM/02 - Chimica Fisica
Settore CHIM/03 - Chimica Generale e Inorganica
|Data di pubblicazione:||gen-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.3390/polym12010211|
|Appare nelle tipologie:||01 - Articolo su periodico|