A Study of Structure-Property Relations in Rigid Polyurethane Foams

In this thesis, the relationship between the chemical structure of reactants, the processing of the foam and the resultant morphology of water blown rigid polyurethane foam have been studied. Chemical variations were systematically made and the morphology and diffusion properties of the foam investi...

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Main Author: Megat-Yusoff, Puteri Sri Melor
Format: Thesis
Published: 1996
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spelling my-utp-ep.7902010-03-18T00:44:28Z A Study of Structure-Property Relations in Rigid Polyurethane Foams 1996-11-04 Megat-Yusoff, Puteri Sri Melor Q Science (General) TP Chemical technology QD Chemistry In this thesis, the relationship between the chemical structure of reactants, the processing of the foam and the resultant morphology of water blown rigid polyurethane foam have been studied. Chemical variations were systematically made and the morphology and diffusion properties of the foam investigated. The chemical variations include polyol arm length, polyol/monol content, water level, type of catalysts and type of isocynates. Various techniques were employed throughout the study: adiabatic temperature rise method to analyse the reaction kinetics, Fourier Transform Infra Red spectroscopy to simultaneously monitor polymerization and microphase separation behaviour, static small angle x-ray scattering, environmental scanning electron microscopy and interference optical microscopy to characterize the final foam morphology and gravimetry diffusion measurements to assess the CO2 diffusion coefficient of the water blown rigid polyurethane foams. The findings have highlighted the dependence of chemical formulations on morphology which in turn determined the observed diffusional property. Shorter polyol arm length, least amount of monol and higher isocynate functionality resulted in smaller cell diameter, thinner cell membrane and higher concentration of hydrogen bonded urea. These in effect gave rise to a denser, rigid structure characterized by a higher value of fractal dimension. A higher fractal dimension value would indicate a lower diffusion coefficient signifying a better thermal insulation property. 1996-11 Thesis http://eprints.utp.edu.my/790/ phd University of Manchester Institute of Science & Technology (UMIST) Materials Science Centre
institution Universiti Teknologi PETRONAS
collection UTP Institutional Repository
topic Q Science (General)
TP Chemical technology
QD Chemistry
spellingShingle Q Science (General)
TP Chemical technology
QD Chemistry
Megat-Yusoff, Puteri Sri Melor
A Study of Structure-Property Relations in Rigid Polyurethane Foams
description In this thesis, the relationship between the chemical structure of reactants, the processing of the foam and the resultant morphology of water blown rigid polyurethane foam have been studied. Chemical variations were systematically made and the morphology and diffusion properties of the foam investigated. The chemical variations include polyol arm length, polyol/monol content, water level, type of catalysts and type of isocynates. Various techniques were employed throughout the study: adiabatic temperature rise method to analyse the reaction kinetics, Fourier Transform Infra Red spectroscopy to simultaneously monitor polymerization and microphase separation behaviour, static small angle x-ray scattering, environmental scanning electron microscopy and interference optical microscopy to characterize the final foam morphology and gravimetry diffusion measurements to assess the CO2 diffusion coefficient of the water blown rigid polyurethane foams. The findings have highlighted the dependence of chemical formulations on morphology which in turn determined the observed diffusional property. Shorter polyol arm length, least amount of monol and higher isocynate functionality resulted in smaller cell diameter, thinner cell membrane and higher concentration of hydrogen bonded urea. These in effect gave rise to a denser, rigid structure characterized by a higher value of fractal dimension. A higher fractal dimension value would indicate a lower diffusion coefficient signifying a better thermal insulation property.
format Thesis
qualification_level Doctorate
author Megat-Yusoff, Puteri Sri Melor
author_facet Megat-Yusoff, Puteri Sri Melor
author_sort Megat-Yusoff, Puteri Sri Melor
title A Study of Structure-Property Relations in Rigid Polyurethane Foams
title_short A Study of Structure-Property Relations in Rigid Polyurethane Foams
title_full A Study of Structure-Property Relations in Rigid Polyurethane Foams
title_fullStr A Study of Structure-Property Relations in Rigid Polyurethane Foams
title_full_unstemmed A Study of Structure-Property Relations in Rigid Polyurethane Foams
title_sort study of structure-property relations in rigid polyurethane foams
granting_institution University of Manchester Institute of Science & Technology (UMIST)
granting_department Materials Science Centre
publishDate 1996
_version_ 1747837933160759296