Search results for "Polymer blend"
showing 10 items of 219 documents
Effect of adding wood flour to the physical properties of a biodegradable polymer
2008
Wood flour/polymer composites (WPC) gained a significant interest during the last decades, due to several advantages related to the use of a natural-organic filler rather than an inorganic-mineral one. However, most of the studies have been performed on composites based on polyolefin matrices. A further step is the use of biodegradable polymers instead of traditional ones. In this work, wood flour (WF), under the form of short fibers, with two different sizes (coarse and fine) was added to a corn starch based biodegradable polymer of the Mater-Bi family. The effect of WF size, WF content, thermal treatment on the mechanical properties was investigated. The tensile mechanical tests showed an…
The Impact of Janus Nanoparticles on the Compatibilization of Immiscible Polymer Blends under Technologically Relevant Conditions
2014
Several hundred grams of Janus nanoparticles (d ≈ 40 nm) were synthesized from triblock terpolymers as compatibilizers for blending of technologically relevant polymers, PPE and SAN, on industry-scale extruders. The Janus nanoparticles (JPs) demonstrate superior compatibilization capabilities compared to the corresponding triblock terpolymer, attributed to the combined intrinsic properties, amphiphilicity and the Pickering effect. Straightforward mixing and extrusion protocols yield multiscale blend morphologies with "raspberry-like" structures of JPs-covered PPE phases in a SAN matrix. The JPs densely pack at the blend interface providing the necessary steric repulsion to suppress droplet …
Controlled Delivery of Gentamicin Antibiotic from Bioactive Electrospun Polylactide-Based Ultrathin Fibers
2011
The purpose of this study was to generate ultrathin fibers based on polylactide (PLA) biopolyester with antimicrobial controlled release capacity to treat bacterial infections. To achieve this objective, gentamicin antibiotic was encapsulated into pure PLA fibers, a blend of PLA–collagen and coaxial fibers containing a skin of PLA and a core of collagen using the electrospinning technique. The morphology of the gentamicin-loaded fibers and the antibiotic distribution within the fibers were examined by SEM and TEM. The drug delivery profile of the different electrospun fibers was analyzed using a spectrophotometric method. The performance for treating common possible post-surgical infections…
Compatibilization of Polypropylene/Polyamide 6 Blend Fibers Using Photo-Oxidized Polypropylene.
2018
The use of polyamide/polyolefin blends has gained importance and concern for years, but they also show some issues to be adequately addressed, such as the incompatibility between the two components. This is usually overcome by using suitable compatibilizers, typically based on functionalized polyolefins. However, there is only little information about the use of a degraded polyolefins to induce compatibilization. This is even truer, as far as polyamide 6/polypropylene (PA6/PP) blends are concerned. In this work, compatibilization of PA6/PP blends by using small amounts of photo-oxidized PP was investigated
Stabilizing organic photocathodes by low-temperature atomic layer deposition of TiO2
2017
Organic semiconductor light absorbers are receiving attention for their potential application in photoelectrochemical (PEC) cells for renewable fuels generation. Key to their advancement is precise control of the interfaces between charge-selective contacts, absorber layers, and electrocatalysts, while maintaining compatibility with an aqueous electrolyte environment. Here we demonstrate a new process for low-temperature atomic layer deposition (ALD) of TiO2 onto a P3HT:PCBM polymer blend surface for stable high-performance organic PEC photocathodes. This ALD TiO2 layer provides three key functions: (1) formation of an electron-selective contact to the polymer to enable photovoltage and pho…
Injection moldability and properties of compatibilized PA6/LDPE blends
2004
An ethylene-acrylic acid copolymer (EAA), either alone or combined with a low molar mass bis-oxazoline compound (PBO), has been used as a compatibilization promoter for blends of polyamide-6 (PA6) with low-density polyethylene (LDPE). The effect of compatibilization on blend processability in injection molding operations and on the properties of the molded specimens has been studied. In the absence of compatibilization, the injection molded articles were shown to have low-quality surface appearance and poor mechanical properties. Both these characteristics were appreciably improved as a result of reactive compatibilization of the blends with EAA and, even more, with the EAA-PBO couple. In f…
Reactive blending of a functionalized polyethylene with a semiflexible liquid crystalline copolyester
1996
Reactive blends (50/50 w/w) of a low molar mass polyethylene containing free carboxylic groups (PEox) and a semiflexible liquid crystalline polyester (SBH 1 : 1 : 2, by Eniricerche) have been prepared at 240 degrees C in a Brabender mixer, in the presence of Ti(OBu)(4) catalyst, for different mixing times (15, 60, and 120 min). In order to prove the formation of a PE-g-SBH copolymer, the blends have been fractionated by successive extractions with boiling toluene and xylene. The soluble fractions and the residues have been analyzed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG and DTG), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM)…
Reactive compatibilization of PA6/LDPE blends with an ethylene–acrylic acid copolymer and a low molar mass bis-oxazoline
2003
Abstract A sample of polyamide-6 (PA) was blended with low density polyethylene (LDPE) in the 80/20 wt/wt ratio, either without and with 2 phr of an ethylene–acrylic acid copolymer (EAA), Which was known to behave as a compatibilizer precursor, and the effect of the addition of small amounts (0.2 or 0.35 phr) of a fourth component, 2,2′-(1,3-phenylene)-bis(2-oxazoline) (PBO), was investigated. The reactions of PBO with EAA, PA and their blends were studied by recording as a function of time the torque applied to the blending apparatuses and by studying the solubility behavior of the products in formic acid. The PALDPE blends were prepared in a co-rotating twin screw extruder and were charac…
Comparative Study of Different Maleic Anhydride Grafted Compatibilizer Precursors toward LDPE/PA6 Blends: Morphology and Mechanical Properties
2005
The study deals with the effectiveness of maleic anhydride grafted styrene-b-ethylene-co-propylene copolymer (SEPMA) as compatibilizer precursor (CP) for blends of low density polyethylene (LDPE) with polyamide-6 (PA). The CP was produced by grafting MA onto SEP in the melt. The specific interactions between the CP and the blends components have been investigated through characterizations of the binary LDPE/CP and PA/CP blends. The compatibilizing efficiency of the MA-grafted SEP, as revealed by the thermal properties and the morphology of the compatibilized blends, has been shown to be excellent. The morphology, as well as the mechanical properties of the compatibilized with SEPMA 75/25 w/…
Morphology and mechanical properties of extruded ribbons of LDPE/PA6 blends compatibilized with an ethylene-acrylic acid copolymer
2003
Two grades of low density polyethylene (LDPE) were blended with polyamide-6 (PA) in the 75/25 and 25/75 wt/wt ratios and shaped into ribbons with a Brabender single screw extruder. An ethylene-acrylic acid copolymer (EAA) was used in the 2 phr concentration as a compatibilizer precursor (CP). The morphology of the ribbons and its evolution during high temperature annealing were investigated by scanning electron microscopy (SEM). The results confirmed that EAA does actually behave as a reactive compatibilizer for the LDPE/PA blends. In fact, in the presence of EAA, the interfacial adhesion is improved, the dispersion of the minor phase particles is enhanced and their tendency toward fibrilla…