MODELING OF ASYMMETRIC MEMBRANE FORMATION .2. THE EFFECTS OF SURFACE BOUNDARY-CONDITIONS

1988-05-20
An analysis is carried out to evaluate the effects of alternate surface boundary conditions on the predictions of our previously developed (Part I) pseudobinary diffusion model for membrane formation by the phase inversion process. Attention is addressed to a comparison of concentration profiles in the quenched film for a constant flux interface (CF) condition and a mass transfer rate (MT) interface condition. A numerical algorithm is developed to handle the MT condition based on an explicit, finite difference marching method. Comparison of concentration profiles with those obtained earlier for the CF boundary condition show that since results for both cases are very similar, either condition can be used in concentration profile calculations. Changes in bath conditions will mainly affect membrane formation through the changed solvent/nonsolvent flux ratio during quenching.
JOURNAL OF APPLIED POLYMER SCIENCE

Suggestions

Kinetics of polyurethane formation between glycidyl azide polymer and a triisocyanate
Keskin, S; Özkar, Saim (Wiley, 2001-07-25)
Kinetics of the polyurethane formation between glycidyl azide polymer (GAP) and a polyisocyanate, Desmodur N-100, were studied in the bulk state by using quantitative FTIR spectroscopy. The reaction was followed by monitoring the change in intensity of the absorption band at 2270 cm-l for NCO stretching in the IR spectrum, and was shown to obey second-order kinetics up to 50% conversion. The activation parameters were obtained from the evaluation of kinetic data at different temperatures in the range of 50-...
Physical Characterization of Inclusion Complexes of Triphenyl Phosphate and Cyclodextrins in Solution.
Zhang, N; Zane, CP; Chen, Y; Yıldırım, Erol; Hinks, D; Tonelli, AE; Vinueza, NR; Pasquinelli, MA (American Chemical Society (ACS), 2020-01-16)
The goal of this work is to provide physical insights into the formation and stability of inclusion complexes (ICs) in aqueous solution between cyclodextrins (CDs) and a common flame retardant, triphenyl phosphate (TPP). Quantum chemistry calculations reveal the possible energetically favorable geometries of TPP in their 1:1 IC form with α-, β-, and γ-CDs as well as their associated complexation, conformational, and interaction energies. High-resolution mass spectrometry (MS) and tandem MS were used with el...
Synthesis and characterization of epoxy based nanocomposites
Basara, G; Yılmazer, Ülkü; Bayram, Göknur (Wiley, 2005-11-01)
Epoxy-clay nanocomposites were synthesized to examine the effects of the content and type of different clays on the structure and mechanical properties of the nanocomposites. Diglycidyl ether of bisphenol-A (epoxy) was reinforced by 0.5-11 wt % natural (Cloisite Na+) and organically modified (Cloisite 3013) types of montmorillonite. SEM results showed that as the clay content increased, larger agglomerates of clay were present. Nano-composites with Cloisite 30B exhibited better dispersion and a lower degree...
Thermal characterization of glycidyl azide polymer (GAP) and GAP-based binders for composite propellants
Selim, K; Özkar, Saim; Yılmaz, Levent (Wiley, 2000-07-18)
Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to investigate the thermal behavior of glycidyl azide polymer (GAP) and GAP-based binders, which are of potential interest for the development of high-performance energetic propellants. The glass transition temperature (T-g) and decomposition temperature (T-d) of pure GAP were found to be -45 and 242 degrees C, respectively. The energy released during decomposition (Delta H-d) was measured as 485 cal/g. The effect of th...
Preparation and Characterization of Low Density Polyethylene/Ethylene Methyl Acrylate Glycidyl Methacrylate/Organoclay Nanocomposites
Coskunses, Fatma Isik; Yılmazer, Ülkü (Wiley, 2011-06-05)
The effects of organoclay type, compatibilizer, and the addition order of components during melt-blending process on the morphology and thermal, mechanical, and flow properties of ternary nanocomposites based on low-density polyethylene (LDPE) were investigated. As a compatibilizer, ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA), as organoclays Cloisites (R) 15A, 25A, and 30B were used. All samples were prepared by a corotating twin screw extruder, followed by injection molding. The highest incre...
Citation Formats
L. Yılmaz, “MODELING OF ASYMMETRIC MEMBRANE FORMATION .2. THE EFFECTS OF SURFACE BOUNDARY-CONDITIONS,” JOURNAL OF APPLIED POLYMER SCIENCE, pp. 1967–1979, 1988, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39175.