Search results for "Polymer blend"
showing 10 items of 219 documents
Effect of block copolymer architecture on the interfacial tension between immiscible polymers
2007
The effect of block copolymer additives on the interfacial tension (σ) is studied for the systems polydimethylsiloxane/polyethyleneoxide (A/B) and polyethylmethylsiloxane/polypropyleneoxide by means of a sessile-drop and a pendant-drop-apparatus. Diblockcopolymers (A-block-B), triblockcopolymers (A-block-B-block-A) and “tooth-brush” like copolymers (A backbone, B brushes) served as additives.
Micromechanics of “raspberry” morphology in PPE/SAN polymer blends compatibilized with linear ABC triblock terpolymers
2015
Abstract The effect of compatibilization with a symmetrical polystyrene- block -polybutadiene- block -poly(methyl methacrylate) (SBM) triblock terpolymer on the morphological and mechanical properties (specifically toughness) of immiscible poly(2,6-dimethyl-1,4-phenylene ether)/poly(styrene- co -acrylonitrile) (PPE/SAN) blends with different blend (w/w) ratios is investigated. We study the effect of blend viscosity on the localization of the compatibilizer at the blend interface, influencing the mechanical properties of the macroscopic material. The impact of the specific morphology of the blends, known as “raspberry morphology”, on the final material will be explained using thermomechanica…
Synergistic effects of Janus particles and triblock terpolymers on toughness of immiscible polymer blends
2017
Abstract By influencing both the interfacial adhesion and the morphology, compatibilizers determine the mechanical properties of polymer blends. Here, we study the mechanical properties, in particular the fatigue crack propagation (FCP) of immiscible blends of poly(2,6-dimethyl-1,4-phenylene ether)/poly(styrene- co -acrylonitrile) (PPE/SAN), compatibilized with Janus nanoparticles (JPs) and linear polystyrene- block -polybutadiene- block -poly(methyl methacrylate) (SBM) triblock terpolymers. Synergistic effects of a mixture of both compatibilizers improve the FCP behavior and reveal the important role of interface stiffness and flexibility on the mechanical properties of polymer blends. The…
Extensional flow of HDPE/LDPE blends
1982
Elongational viscosity data, obtained through the converging flow analysis by Cogswell, are presented for two types of HDPE/LDPE blends at various compositions and different temperatures. The results relative to the homopolymer parents compare favourably with literature data obtained also with different and more sophisticated techniques. Those relative to blends show peculiar features for the two cases: when the newtonian viscosity of the LDPE is higher all the blends show a behaviour typical of the LDPE with a maximum in η el /η0 enhanced at small percentage of HDPE; when the newtonian viscosity of the LDPE is similar to that of the HDPE there is only a gradual change in the properties.
Controlled production of patchy particles from the combined effects of nanoprecipitation and vitrification
2017
Using molecular dynamics simulations, we study a simple and scalable method for fabricating patchy nanoparticles via the assembly of binary polymer blends under a rapid solvent exchange. Patchiness can be achieved by incorporating a glassy component, which kinetically traps the particle morphology along the path to the equilibrium configuration. Our simulations reveal that the number of surface patches increases for larger nanoparticles and for more asymmetric blend ratios, while the size distribution of the patches remains rather uniform. Other than multi-patch nanoparticles, Janus structures have been obtained for small nanoparticles. Further, ribbon structures with elongated surface doma…
Toward the Decarbonization of Plastic: Monopolymer Blend of Virgin and Recycled Bio-Based, Biodegradable Polymer.
2022
Decarbonization of plastics is based on two main pillars: bio-based polymers and recycling. Mechanical recycling of biodegradable polymers could improve the social, economic and environmental impact of the use of these materials. In this regard, the aim of this study was to investigate whether concentrations of the same recycled biopolymer could significantly affect the rheological and mechanical properties of biodegradable monopolymer blends. Monopolymer blends are blends made of the same polymers, virgin and recycled. A sample of commercially available biodegradable blend was reprocessed in a single-screw extruder until two extrusion cycles were completed. These samples were exposed to gr…
Effect of Polyhydroxyalkanoate (PHA) Concentration on Polymeric Scaffolds Based on Blends of Poly-L-Lactic Acid (PLLA) and PHA Prepared via Thermally…
2022
Hybrid porous scaffolds composed of both natural and synthetic biopolymers have demonstrated significant improvements in the tissue engineering field. This study investigates for the first time the fabrication route and characterization of poly-L-lactic acid scaffolds blended with polyhydroxyalkanoate up to 30 wt%. The hybrid scaffolds were prepared by a thermally induced phase separation method starting from ternary solutions. The microstructure of the hybrid porous structures was analyzed by scanning electron microscopy and related to the blend composition. The porosity and the wettability of the scaffolds were evaluated through gravimetric and water contact angle measurements, respective…
Janus Nanostructures from ABC/B Triblock Terpolymer Blends
2019
Lamella-forming ABC triblock terpolymers are convenient building blocks for the synthesis of soft Janus nanoparticles (JNPs) by crosslinking the B domain that is &ldquo
Joint Aqueous Solutions of Dextran and Bovine Serum Albumin: Coexistence of Three Liquid Phases
2014
The phase diagram of the system water/dextran (DEX)/BSA was measured as well as modeled. On the experimental side, cloud points were determined and the coexisting phases were analyzed. The theoretical calculations use an approach capable of describing solutions of chain polymers and of globular proteins with the same formalism. The required thermodynamic input comes from experiments concerning the binary subsystems, except for the polymer blend for which one interaction parameter had to be adjusted. Both sources of information yield the same essential features: the existence of a large composition area of immiscibility, starting from the subsystem DEX/BSA and extending well into the region …