https://cyberleninka.org/article/n/768408.pdf

Mechanical properties of graphene and graphene-based nanocomposites

Thermal stability and flame retardancy of polyurethanes

https://hal.archives-ouvertes.fr/hal-01087663/document

Structuration, selective dispersion and compatibilizing effect of (nano)fillers in polymer blends

https://espace.library.uq.edu.au/view/UQ:08f48a6/UQ08f48a6_OA.pdf

Degradation and stabilization of polyurethane elastomers

Biodegradable polymer blends consisting of poly(L-lactic acid) (PLLA) and poly(butylene succinate) (PBS) were prepared in the presence of dicumyl peroxide (DCP). The effects of DCP content on the mechanical properties, thermal and rheological behavior, phase morphology as well as the toughening mechanism of the blends were investigated. The notched Izod impact strength of PLLA/PBS (80/20) blend significantly increased after the addition of 0.05–0.2 phr DCP, but the strength and modulus monotonically decreased with increasing DCP content. PBS acted as a nucleating agent at the environmental temperature below its melting temperature and accelerated the crystallization rate of PLLA but had little effect on its final degree of crystallinity. The degree of crystallinity of PBS and the cold crystallization ability of PLLA gradually reduced with increasing DCP content. The addition of DCP induced an increase in viscosity of the blends at low frequencies as well as finer dispersion of PBS particles and better interfacial adhesion between PLLA and PBS, indicating the in situ compatibilization occurred between the two components. The optical clarity of PLLA/PBS blends was significantly improved after the addition of DCP, which was in accordance with the crystallization behavior and phase structure of the blends. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

Toughening modification of PLLA/PBS blends via in situ compatibilization

Degradation of polymer blends: A brief review

This work reports a study on the effect of multiple reprocessing on the properties of poly(lactic acid) (PLA) filled with graphene nanoplatelets (GnP) compared to the melt reprocessed neat polymeric matrix. In particular, morphological, X-Ray Diffraction and Micro-Raman analyses, intrinsic viscosity measurements, thermal, rheological and mechanical tests were carried out on materials reprocessed up five times by means of a single screw extruder. The results indicated that the presence of GnP decreased the degradation rate as a function of the reprocessing cycles in comparison with the neat PLA that, on the contrary, showed a more drastic reduction of the molecular weight. Moreover, the reprocessing improved the particle dispersion and reduced the presence of GnP aggregates.

/pdf/reprocessing-of-pla-graphene-nanoplatelets-nanocomposites-1ytjuc70sm.pdf

Reprocessing of PLA/Graphene Nanoplatelets Nanocomposites

Compatibilized polyamide 6/polyethylene blend–clay nanocomposites: Effect of the degradation and stabilization of the clay modifier

Polymer composites containing natural fibers are receiving growing attention as possible alternatives for composites containing synthetic fibers. The use of biodegradable matrices obtained from renewable sources in replacement for synthetic ones is also increasing. However, only limited information is available about the creep behavior of the obtained composites. In this work, the tensile creep behavior of PLA based composites, containing flax and jute twill weave woven fabrics, produced through compression molding, was investigated. Tensile creep tests were performed at different temperatures (i.e., 40 and 60 °C). The results showed that the creep behavior of the composites is strongly influenced by the temperature and the woven fabrics used. As preliminary characterization, quasi-static tensile tests and dynamic mechanical tests were carried out on the composites. Furthermore, fabrics (both flax and jute) were tested as received by means of quasi-static tests and creep tests to evaluate the influence of fabrics mechanical behavior on the mechanical response of the resulting composites. The morphological analysis of the fracture surface of the tensile samples showed the better fiber-matrix adhesion between PLA and jute fabric.

Creep Behavior of Poly(lactic acid) Based Biocomposites

The rising concerns in terms of environmental protection and the search for more versatile polymer-based materials have led to an increasing interest in the use of polymer composites filled with natural organic fillers (biodegradable and/or coming from renewable resources) as a replacement for traditional mineral inorganic fillers. At the same time, the recycling of polymers is still of fundamental importance in order to optimize the utilization of available resources, reducing the environmental impact related to the life cycle of polymer-based items. Green composites from biopolymer matrix and wood flour were prepared and the investigation focused on several issues, such as the effect of reprocessing on the matrix properties, wood flour loading effects on virgin and reprocessed biopolymer, and wood flour effects on material reprocessability. Tensile, Dynamic-mechanical thermal (DMTA), differential scanning calorimetry (DSC) and creep tests were performed, pointing out that wood flour leads to an improvement of rigidity and creep resistance in comparison to the pristine polymer, without compromising other properties such as the tensile strength. The biopolymer also showed a good resistance to multiple reprocessing; the latter even allowed for improving some properties of the obtained green composites.

Maria Chiara Mistretta

Papers

Degradation of polymer blends: A brief review

Reprocessing of PLA/Graphene Nanoplatelets Nanocomposites

Compatibilized polyamide 6/polyethylene blend–clay nanocomposites: Effect of the degradation and stabilization of the clay modifier

Creep Behavior of Poly(lactic acid) Based Biocomposites

Mechanical, Thermomechanical and Reprocessing Behavior of Green Composites from Biodegradable Polymer and Wood Flour