Loianno, Valerio (2018) Thermodynamics of Thermoplastic Polymers and their Solutions. [Tesi di dottorato]
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Valerio_Loianno_31.pdf Download (6MB) | Anteprima |
| Tipologia del documento: | Tesi di dottorato | ||||||
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| Lingua: | English | ||||||
| Titolo: | Thermodynamics of Thermoplastic Polymers and their Solutions | ||||||
| Autori: |
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| Data: | 10 Dicembre 2018 | ||||||
| Numero di pagine: | 136 | ||||||
| Istituzione: | Università degli Studi di Napoli Federico II | ||||||
| Dipartimento: | Ingegneria Chimica, dei Materiali e della Produzione Industriale | ||||||
| Dottorato: | Ingegneria dei prodotti e dei processi industriali | ||||||
| Ciclo di dottorato: | 31 | ||||||
| Coordinatore del Corso di dottorato: |
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| Tutor: |
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| Data: | 10 Dicembre 2018 | ||||||
| Numero di pagine: | 136 | ||||||
| Parole chiave: | polymer, sorption, thermodynamics | ||||||
| Settori scientifico-disciplinari del MIUR: | Area 03 - Scienze chimiche > CHIM/05 - Scienza e tecnologia dei materiali polimerici Area 02 - Scienze fisiche > FIS/03 - Fisica della materia Area 09 - Ingegneria industriale e dell'informazione > ING-IND/22 - Scienza e tecnologia dei materiali |
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| Depositato il: | 07 Gen 2019 23:41 | ||||||
| Ultima modifica: | 23 Giu 2020 14:18 | ||||||
| URI: | http://www.fedoa.unina.it/id/eprint/12614 |
Abstract
Glassy organic polymers are technologically important across the gamut of materials applications from structural (hyperbaric windows) to electronic (ionic conductors, surface coatings for printed circuit boards) to environmental (membranes for industrial gas separation). A formal description and understanding of the glass transition temperature is necessary in order to determine the configurational state and hence physical properties of the glass. Moreover, the non-equilibrium glassy state appears to be unstable: volume-relaxation studies of glassy materials have revealed that they undergo slow processes, which attempt to establish equilibrium. These types of retardation/ relaxation phenomena are called physical ageing. As well as pressure and temperature, sorption of a plasticizer may affect in several ways the membrane physical properties. Generally speaking structural rearrangement of the chains is enhanced and, consequently, the glass transition temperature decreases, physical ageing is usually speed up, the membrane is affected by swelling and/or plasticization and even crystallization can be activated. The research work focuses on the investigation of industrial polymers’ glassy – rubbery behaviour due to thermodynamic state variables change (e.g. temperature T, mechanical pressure P and solvent content ) within the polymer matrix. The goal is to obtain a fundamental insight of the sorption process on both macroscopic and microscopic levels. As a result several polymer—penetrant systems have been studied. Different techniques have been implemented to achieve this goal: dilatometry, MTDSC, gravimetry, manometry and in situ FTIR. The instruments used are: a PVT apparatus from GNOMIX®; a MDSC from TA Instruments®; four different handmade systems consisting of a CAHN microbalance from Thermo Fisher Scientific®, a QSM from RUSKA Co.®, a pressure decay system from MKS® and finally a FTIR from Perkin-Elmer®. All data have been modelled with statistical thermodynamic theories and empirical approaches . The study is divided as follows: the first chapter introduces the research goal and fields of application along with the theoretical background for membrane science; the second chapter reports the study conducted on the system PEI—CO2; the third chapter describes the results obtained on the PS—Toluene system; finally in the fourth chapter the results for the PPO—benzene system are given. The order in which these systems are presented is related to the increase of structural modifications as a result of polymer— penetrant interactions.
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