Preparation and phase behavior of blends of polysulfone‐based polymers with phosphorous‐containing smectic‐A liquid crystals

Abstract

Preparation and experimental studies on the phase transitions and morphology of novel polymer-dispersed liquid crystal (PDLC) mixtures of polysulfone UDEL-3000 (PSU) or its derivatives (chloromethylated polysulfone or polysulfone containing lateral phosphaphenanthrene substituent) and a phosphorus-containing liquid crystalline polymer (LCC) that exhibit isotropic/nematic/smectic-A mesophase transition were performed. The mesomorphic properties of PDLC have been investigated by differential scanning calorimetry and polarizing optical microscopy. Mesophases structures were also investigated by X-ray diffraction measurements, the diffraction pattern being in close dependence on the polysulfone structure and PDLC composition. The effect of the phosphorus content on the thermal properties was evaluated by thermogravimetric analysis. The results reveal that the composites were stable up to 3378C in air showing initial decomposition temperatures in the range of 337-3688C and a 10% weight loss in the range of 357-3978C. The presence of P in the structure of LCC leads to higher char yields at 7008C, for PDLCs composites, increasing with the content of phosphorus-containing polymer. POLYM. ENG.

Thermal Degradation Studies of Poly(2-ethyl hexyl acrylate) in the Presence of Nematic Liquid Crystals

“…TGA analyses were per-formed to quantify the amount of E7 encapsulated in the polymer particles [41]. The prep-aration and experimental studies of phase transitions and morphology of new PDLC sys-tems based on Udel-3000 polysulfone (PSU) or its derivatives (chloromethylated PSU or PSU with a phosphaphenanthrene side substituent) and a phosphorus-containing LC polymer (LCP) were evaluated by Tachita et al [42]. These researchers showed that the presence of the phosphorus atom in the structure of the LCP and also in the polymer matrix, based on phosphorylated PSU, improved the key properties such as flame retardancy, thermal stability, and so on.…”

Luminescent guest–host composite films based on an azomethine dye in different matrix polymers

“…The first polymer is polysulfone, recognized as good insulator, transparent, which has high light transmittance, hydrolytic stability, resistance at heat and chemicals, biocompatibility and so on. All these properties enable it to be used in many applications, as pure polymer or as matrix for composite materials [17][18][19][20].…”

Miscibility behavior of epoxy thermosets loaded with an oligophosphonate

“…The utilization of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) or its derivatives has been shown to significantly enhance the flame retardancy of epoxy resins . Our group has been focused on the design and synthesis of phosphorus‐containing monomers and/or polymers, especially derivatives of DOPO, exhibiting excellent flame retardant properties . The main advantage of such systems is that the flame retardancy can be improved at concentration lower than 3 wt % phosphorus.…”