Improvement of the Thermal Stability of Polymer Bioblends by Means of Reactive Extrusion.

Poly(lactic acid) (PLA) and biosourced polyamide (PA) bioblends, with a variable PA weight content of 10-50%, were manufactured by melt blending in order to improve the behavior of PLA against thermal degradation. The effect of reactive extrusion on the thermal performance of PLA within bioblends was analyzed. The reactive extrusion was made by means of the addition of a styrene-acrylic multi-functional-epoxide oligomeric reactive agent (SAmfE), with the commercial name of Joncryl.

Implications of the Circular Economy in the Context of Plastic Recycling: The Case Study of Opaque PET.

The use of recycled opaque PET (r-O-PET, with TiO) as a reinforcement for the recycled polypropylene matrix (r-PP) was evaluated through the life cycle assessment according to different scenarios corresponding to two different recycled blends and considered two virgin raw plastic material as reference materials when comparing the environmental performance of the proposed treatments. The results indicate that the environmental performance was quite different for each blend, since the additional extrusion process required in scenario 2 (blend with TiO) causes all impact categories analysed to report higher values when compared with scenario 1 (blend without TiO). The stage that contributes the most corresponds to the different extrusion processes included in both recycling blends, representing at least 80% of the total for global warming.

Cellulose nanocrystals as nucleating agents for the strain induced crystallization in natural rubber.

Vulcanized natural rubber (NR)/cellulose nanocrystals (CNC) composites with a CNC content of up to 5 wt% using physical blending and dicumyl peroxide crosslinking were prepared. The tensile properties were investigated at slow and high strain rates. The slow strain rate tests revealed an increase of the elastic modulus concomitant with a decrease of strain at the crystallization onset while increasing the CNC fraction.

Ice-Template Crosslinked PVA Aerogels Modified with Tannic Acid and Sodium Alginate.

With the commitment to reducing environmental impact, bio-based and biodegradable aerogels may be one approach when looking for greener solutions with similar attributes to current foam-like materials. This study aimed to enhance the mechanical, thermal, and flame-retardant behavior of poly(vinyl alcohol) (PVA) aerogels by adding sodium alginate (SA) and tannic acid (TA). Aerogels were obtained by freeze-drying and post-ion crosslinking through calcium chloride (CaCl) and boric acid (HBO) solutions.

Innovative One-Shot Paradigm to Tune Filler-Polymer Matrix Interface Properties by Plasma Polymer Coating in Osteosynthesis Applications.

The present study aims to improve the interfacial bonding between hydroxyapatite particles (HAs) and polylactide (PLA) to enhance the mechanical performance and biocompatibility of bone implants based on HA/PLA. For this, one-shot surface functionalization of HA via plasma polymerization is developed. Taking advantage of acetylene plasma chemistry, the hydrophobicity of HA particles was finely tuned prior to their introduction into a PLA matrix via an extrusion process.

Orientation of Polylactic Acid-Chitin Nanocomposite Films via Combined Calendering and Uniaxial Drawing: Effect on Structure, Mechanical, and Thermal Properties.

The orientation of polymer composites is one way to increase the mechanical properties of the material in a desired direction. In this study, the aim was to orient chitin nanocrystal (ChNC)-reinforced poly(lactic acid) (PLA) nanocomposites by combining two techniques: calendering and solid-state drawing. The effect of orientation on thermal properties, crystallinity, degree of orientation, mechanical properties and microstructure was studied.

Structure and Properties of Reactively Extruded Opaque Post-Consumer Recycled PET.

The recyclability of opaque PET, which contains TiO nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed.

Extruded-Calendered Sheets of Fully Recycled PP/Opaque PET Blends: Mechanical and Fracture Behaviour.

This work presents the experimental results of the mechanical and fracture behaviour of three polymeric blends prepared from two recycled plastics, namely polypropylene and opaque poly (ethylene terephthalate), where the second one acted as a reinforcement phase. The raw materials were two commercial degrees of recycled post-consumer waste, i.e.

Impact of Titanium Dioxide in the Mechanical Recycling of Post-Consumer Polyethylene Terephthalate Bottle Waste: Tensile and Fracture Behavior.

This work provides an experimental analysis regarding the fracture behavior of recycled opaque PET (rPET-O) containing titanium dioxide (TiO) under plane stress conditions. For this purpose, a commercially post-consumer transparent colored/opaque PET flakes mix was processed using a semi-industrial extrusion calendering process. The manufactured rPET-O sheets had a TiO content of 1.

Effect of the Strain Rate on Damage in Filled EPDM during Single and Cyclic Loadings.

The effect of the strain rate on damage in carbon black filled Ethylene Propylene Diene Monomer rubber (EPDM)stretched during single and multiple uniaxial loading is investigated. This has been performed by analyzing the stress-strain response, the evolution of damage by Digital Image Correlation (DIC), the associated dissipative heat source by InfraRed thermography (IR), and the chains network damage by swelling. The strain rates were selected to cover the transition from quasi-static to medium strain rate conditions.

Effect of Chitin Nanocrystals on Crystallization and Properties of Poly(lactic acid)-Based Nanocomposites.

The crystalline phase of poly(lactic acid) (PLA) has crucial effects on its own properties and nanocomposites. In this study, the isothermal crystallization of PLA, triethyl citrate-plasticized PLA (PLA-TEC), and its nanocomposite with chitin nanocrystals (PLA-TEC-ChNC) at different temperatures and times was investigated, and the resulting properties of the materials were characterized. Both PLA and PLA-TEC showed extremely low crystallinity at isothermal temperatures of 135, 130, 125 °C and times of 5 or 15 min.

The Effect of Titanium Dioxide Surface Modification on the Dispersion, Morphology, and Mechanical Properties of Recycled PP/PET/TiO PBNANOs.

Titanium dioxide (TiO) nanoparticles have recently appeared in PET waste because of the introduction of opaque PET bottles. We prepare polymer blend nanocomposites (PBNANOs) by adding hydrophilic (hphi), hydrophobic (hpho), and hydrophobically modified (hphoM) titanium dioxide (TiO) nanoparticles to 80rPP/20rPET recycled blends. Contact angle measurements show that the degree of hydrophilicity of TiO decreases in the order hphi > hpho > hphoM.