Search results for "Phosphazene"
showing 5 items of 15 documents
Effect of adding new phosphazene compounds to poly(butylene terephthalate)/polyamide blends. II: Effect of different polyamides on the properties of …
2006
Poly(butylene terephthalate) (PBT) and a sample of polyamide have been melt processed in the presence of two new phosphazene compounds, namely 2,2-dichloro-4,4,6,6-bis[spyro(2',2"-dioxy-1',1"-biphenyl)]cyclotriphosphazene (2Cl-CP) and 2,2-bis(2-methoxy-4-methyleneoxy-phenoxy)-4,4,6,6-bis[spyro(2',2"-dioxy-1',1"-biphenyl)]cyclophosphazene (CP-2EPOX). The blends were prepared by using polyamide 6 (PA6) and polyamide 6,6 (PA66) in 25/75 and 75/25 w/w compositions by using a co-rotating twin-screw extruder. The materials have been completely characterized from a mechanical, rheological, and morphological point of view. The results indicate that the additives used cause an increase of the ruptur…
Reactions Occurring during the Melt Mixing of Nylon 6 and Oxazoline−Cyclophosphazene Units
2009
Specific reactions of amino and carboxyl end groups of Nylon 6 with the reactive oxazoline groups belonging to a cyclophosphazene compound (referred as CP20XA) were carried out at 240 °C for different times, under inert atmosphere. Ny6 polymers terminated with one specific reactive chain end (-COOH or NH2) were reacted with different amounts of CP20XA to study the kinetic order of the reactions. All Ny6-CP20XA reacted products soluble in trifluoroethanol (TFE) were well characterized by MALDI-TOF MS, FT-IR and ( 1H and 13C) NMR techniques. The MALDI-TOF results show that the oxazoline rings react with the carboxyl chain ends of Ny6 following second-order kinetics. The reactions with amino c…
TI: Cyclophosphazenes as polymer modifiers
2003
The utilization of cyclophosphazenes as polymer modifiers is reviewed, with particular concern to their exploitation as versatile chain extenders, possibly for recycle problems, crosslinkers, to enhance mechanical properties of polymeric materials, branchers, to selectively introduce ramifications in linear polymers, and compatibilizers, to favor the formation of blends between originally incompatible organic macromolecules. The great versatility of the synthetic methods put forward for these substrates, together with the ease of controlling their modification, functionalization and reactivity are important parameters for the evaluation of which type of use is more feasible for these trimer…
On the Preparation and the Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene(co)acrylic Acid Copoly…
2006
Samples of HDPE and PA6 have been meltprocessed in the presence of two new phosphazene compounds, CP-2EPOX and CP-2OXA together with an ethylene/ acrylic acid copolymer. The blends have been prepared in an industrial twin-screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE-rich blend in the presence of CP-2EPOX. This result can be attributed both …
Cyclo- and Polyphosphazenes for Biomedical Applications
2022
Cyclic and polyphosphazenes are extremely interesting and versatile substrates characterized by the presence of -P=N- repeating units. The chlorine atoms on the P atoms in the starting materials can be easily substituted with a variety of organic substituents, thus giving rise to a huge number of new materials for industrial applications. Their properties can be designed considering the number of repetitive units and the nature of the substituent groups, opening up to a number of peculiar properties, including the ability to give rise to supramolecular arrangements. We focused our attention on the extensive scientific literature concerning their biomedical applications: as antimicrobial age…