Water-transport properties in polyetherimide blends with a liquid crystal polymer

Abstract

ABSTRACT:The effect of the addition of a liquid crystal polymer (Rodrun ® ) on the sorption and transport properties of water through films of a polyetherimide (PEI, Ultem 1000) was investigated. A Cahn electrobalance was employed for measuring the water uptake by the polymer samples. Sorption measurements were made with films of PEI, Rodrun, and heterogeneous PEI/Rodrun blends at different water activities at 30°C. In all cases, diffusion and sorption coefficients decreased when the amount of Rodrun increased. Values of the water-sorption isotherms were adjusted to different models. Permeabilities for the different samples were indirectly obtained using experimental values of the solubility and diffusion coefficients described above. Furthermore, permeabilities of the binary composite material were calculated on the basis of those of the pure components and some theoretical assumptions concerning blend morphology. Results were consistent with a Rodrun structure in the composite intermediate between a fibrillar and a laminar morphology.

Determination of the diffusion coefficients of organic solvents in polyepichlorohydrin: A comparative study of inverse gas chromatography and sorption methods

“…These data have been compared with those obtained with sorption measurements. Figure 7 shows an appropriate plot of sorption data38 used to calculate D from the slope at 40°C.…”

“…However, for quantitative values of D from CЈ, we need the value of q, and that is calculated from sorption data of toluene in PECH films. From an adequate treatment 38 of sorption experiments [see Fig. 2 and eq.…”

Nanomechanical and surface frictional characteristics of a copolymer based on benzoyl-1,4-phenylene and 1,3-phenylene

“…The PC M w measured by light scattering (absolute method) is reported as 26,300, while the relative M w determined by GPC using polystyrene standards is reported as 57,000 [23]. PEI relative M w measured by GPC using polystyrene standards is reported as 52,000 [24]; actual molecular weight is in the range of 20,000-30,000 [25]. Mica discs (9.9 mm diameter, Ted Pella, Inc.) were used as the substrate for PS and SRP films.…”

Effect of hygroscopic materials on water vapor permeation and dehumidification performance of poly(vinyl alcohol) membranes

“…The unique properties of Nafion are due to highly hydrophilic perfluorovinyl ether groups terminated with sulfonate groups incorporated onto its hydrophobic tetrafluoroethylene backbone. Therefore, to improve the water vapor permeability of a poorly permeable polymer, strong hydrophilic components are usually incorporated in the polymer matrix either under chemical (such as sulfonation, fluorination, block co‐polymer formation) or physical blending processes . Of these processes, physical blending processes are more preferable because they are more controllable, environmental friendly and inexpensive.…”

“…Therefore, to improve the water vapor permeability of a poorly permeable polymer, strong hydrophilic components are usually incorporated in the polymer matrix either under chemical (such as sulfonation, fluorination, block co-polymer formation 11,[14][15][16][17][18][19][20][21][22] or physical blending processes. 6,7,9,10,12,[23][24][25] Of these processes, physical blending processes are more preferable because they are more controllable, environmental friendly and inexpensive. Although there have been many reports on these processes, how hydrophilic components affect water permeation is still questionable.…”