Uso di idrotalciti in compositi a matrice PLA preparati nel fuso

Progress in Understanding of the Interactions between Functionalized Polyolefins and Organo-Layered Double Hydroxides

The dispersion of organo-layered double hydroxides (O-LDH) in functionalized polyolefins (POs) is investigated. Two different polyethylene matrices (maleic anhydride (MAH) and diethyl maleate functionalized) are tested and a hydrogenated fatty acid modified LDH is used. The attention is focused on evidencing the interaction between the functional groups of the polymer and the O-LDH through FT-IR. Moreover, a combination of solvent fractionation, morphological, and rheological characterizations enables to gain a deeper insight into the structure of these composites. In particular, the formation of bridging bonds between the particles and MAH functionalized macromolecules is assumed, possibly…

Functionalized poly(butylene succinate) by nitroxide radical coupling

In recent years there has been a growing interest in developing sustainable alternatives to oil-based plastics. In particular, biodegradable aliphatic polyesters, such as poly(lactic acid) (PLA) and poly(butylene succinate) (PBS), are becoming increasingly important due to their valuable properties including thermoplastic processability and thermo-mechanical properties. Nonetheless, these materials present several drawbacks, such as the lack of reactive functionalities that are limiting their applications, versatility and successful use as commodity plastics. In this work it was investigated for the first time a new method of preparation of functionalized PBS by a post-polymerization approa…

Advanced nanofillers for polymers: antioxidants immobilized in layered clays

Effects of phenolic-like intercalated layered double hydroxides on poly(lactic acid) based nanocomposites

Two phenolic-like antioxidants (AOs), 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate and 6-hydroxy-2,5,7,8-tetrametilcromano-2-carboxylate anions, were intercalated by anion exchange in layered double hydroxides (LDHs). The two AO-LDHs were dispersed by ultrasound-assisted solution mixing in poly(lactic acid) (PLA) and the thermal oxidation stability of the composites was evaluated following the variation of the molecular weight by SEC, after a controlled aging process, and determining the oxidation induction time (OIT) by DSC. The results evidenced that the intercalation of both the AO molecules within the LDH galleries prevent their own thermal and thermo-oxidative degradation as well a…

Recycling ground tire rubber (GTR) scraps as high-impact filler of in-situ produced polyketone matrix

Grafting of polymer chains on the surface of carbon nanotubes via nitroxide radical coupling reaction

Poly(butylene succinate)/MWCNTs nanocomposites with improved dispersion and with nanotubes embedded/immobilized into the polymer matrix were here prepared by an alternative "grafting to" method based on thenitroxide radical coupling reaction. Poly(butylene succinate) (PBS) was grafted on the surface of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) modified multi-walled carbon nanotubes (MWCNTs) via a nitroxide radical coupling reaction. TEMPO functionalized MWCNTs (MWCNTs-g-TEMPO) were synthesized using the Cu(I)-catalyzed azide/alkyne click chemistry approach and the covalent bond of the nitroxide moieties onto the MWCNTs was confirmed via electron paramagnetic resonance (EPR) spectroscopy.…