Theoretical Analysis of Butane Isomers Separation using Various Membrane Process Configurations

Polymer is among the favorite materials used for membrane separation as they are cheap, easily cast, low maintenance cost and commercially easy to get eventhough the material needs to be altered to meet the separation industry specific needs. There are two common issues in membrane preparation which are the produced sheet are too brittle and has no strength to withstand pressure during separation process and the porosity of the sheet sometimes not suitable with the gas kinetic diameter for the separation to occur. PEBAX or Poly ether block amide is the answer for the issues as this elastomer provides good mechanical strength from the hard segment of the crystalline poly amide block while the soft polyether will drive the separation process. This unique material can be casted either by phase inversion of the PEBAX itself with other polymer or by coating them on the other polymer substrate

A comparative experimental and molecular simulation study on the mechanical and morphological behaviors of adamantane-based polypropylene composites

The main objectives of this work were to construct and characterize polypropylene and adamantane (PP/ADM) nanocomposites experimentally and to identify their mechanical properties using molecular dynamics (MD) simulation. Samples with different contents of ADMs (0.5, 1, 2 and 4 weight percent (wt%)) were prepared using melt mixing method. It was observed that ADM nanofillers had significant effects on mechanical properties (Young’s modulus) of PP nanocomposites. Furthermore an appropriate simulation model was developed to find mechanisms of dispersion and aggregation of the ADMs and to predict bulk properties of the nanocomposite. While former researches claimed that homogeneous filler dispersion exists only at the intermediate level of interfacial interaction between polymer and nanoparticle, according to results of current study entropy has substantial influence on dispersion process. In other words, entropy which controls the interfacial parameters such as how ADMs attach to the polymer chains (either by chain end or middle of the backbone), is a determining agent in dispersion and aggregation mechanism. Consequently chains entropy plays a significant role in enhancement of the nanocomposites Young’s modulus. The trend of modulus alterations demonstrated that the entrance of ADMs at the chains contact point reinforced the polymer matrix and hence increased the modulus intensively. On the other hand, relative dispersion of ADMs and their small aggregates enhanced the modulus. However, ADMs aggregation caused by attaching to the joined ends, made a dramatic decline in Young’s modulus