Mixing and structural properties of model polymer solutions : molecular theory and simulation /
Recent advances in new single-site catalysts continue to fuel an already growing polymer market. As the market increases, a better understanding of polymers becomes critical. The majority of this understanding has been acquired through experimentation. While important, experimentation may be expensi...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733675941&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Recent advances in new single-site catalysts continue to fuel an already growing polymer market. As the market increases, a better understanding of polymers becomes critical. The majority of this understanding has been acquired through experimentation. While important, experimentation may be expensive and time consuming. Thus, it is desirable to predict polymer properties from molecular level characteristics. While a large amount of work has been performed in the area of overall properties of pure and mixture fluids, little work has been done in the area of mixing properties. Our initial effort into this area includes investigating the ability of the compressible Flory, generalized Flory dimer, and interpolating equations of state to predict mixing properties of a model polymer system. In determining the accuracy of the equations, Monte Carlo simulations have been performed in the Gibbs ensemble. A problem in the simulation of these systems, limited access to sampling space, has occurred and an established remedy has been discussed. We have determined that the most effective solution to the problem is a combination of conventional moves and the established correction. Predictions of the overall pressure, osmotic pressure, activity coefficient and Flory Chi parameter have been compared with simulation results, good agreement occurs at high densities, long chain lengths, and high chain concentrations except for the compressible Flory equation of state which only provides qualitatively correct predictions for the mixing properties. The structure of the fluid also is discussed. An increase in the packing fraction results in chain contraction. The addition of a monomeric solvent causes solvation in low to medium packing fraction fluids. Because the addition of solvent increases the packing fraction, the chains also contract. The effect of increasing packing fraction is stronger than the addition of solvent. The monomeric solvent forms clusters over the range of densities. |
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| Item Description: | Vita. "Major Subject: Chemical Engineering". Includes one CD-ROM in back of book. |
| Physical Description: | xii, 144 leaves : illustrations ; 28 cm. + 1 CD-ROM. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 137-142). |