The control of the properties of polyethylene through its polymerisation
The control of the properties of polyethylene through its polymerisation
In order to understand correlations between structural
models of polymers and observed properties, various unusual polymerisations of
ethylene were carried out. A detailed description of the polymerisation
equipment and procedure is given. The effect of the major polymerisation
parameters is reported and a selection of our own polymers is described.
Molecular characterisation (light scattering, G.P.C. and
infrared) examination were made on our polymers as well as commercial ones.
Melt viscosity was studied using a cone and plate rheometer. Mechanical
property studies were made by impact and tensile experiments. Crystallisation
studies were made by density determination of the degree of crystallinity and
lamellar thickness by Raman Spectroscopy.
Molecular characterisation revealed that some samples
prepared here have relatively high molecular weight values (about 8 to 10 times
those of commercial grades used as comparisons). The melt and mechanical
properties are very different from the comparisons. Some of the differences can
be explained through molecular weight grounds alone but it is not sufficient.
It is known that an increase in molecular weight causes mechanical properties
to change because networks occur. This is due to molecular entanglements which
Inevitably occur in the longest chains. It is considered that the Improved
properties cannot fully be explained on this basis alone. It is suggested that
the explanation comes from the original polymerisation reaction. In order to
make the polymers^ polymerisation reactions were carried out such a way that
the growing chains could easily entangle with each other. It is suggested that
this idea should be further studied.
Some evidence was also found that some of the entanglements
are destroyed during the working up of the polymers after they have been made.
In the conclusion of the thesis, it is suggested that the
project has to be enlarged to maximise the presence of entanglements which
might lead to the creation of new polymeric grades which could even become gels
in the molten state.
University of Southampton
Mathieu, Philippe Jean-Marie
f7fa4df4-1b58-4c15-a559-e37c8fe071c7
1981
Mathieu, Philippe Jean-Marie
f7fa4df4-1b58-4c15-a559-e37c8fe071c7
Hendra, P.J.
c38c1fd1-6a9f-431d-a8ea-ac9961f4acbb
Mathieu, Philippe Jean-Marie
(1981)
The control of the properties of polyethylene through its polymerisation.
University of Southampton, Doctoral Thesis, 158pp.
Record type:
Thesis
(Doctoral)
Abstract
In order to understand correlations between structural
models of polymers and observed properties, various unusual polymerisations of
ethylene were carried out. A detailed description of the polymerisation
equipment and procedure is given. The effect of the major polymerisation
parameters is reported and a selection of our own polymers is described.
Molecular characterisation (light scattering, G.P.C. and
infrared) examination were made on our polymers as well as commercial ones.
Melt viscosity was studied using a cone and plate rheometer. Mechanical
property studies were made by impact and tensile experiments. Crystallisation
studies were made by density determination of the degree of crystallinity and
lamellar thickness by Raman Spectroscopy.
Molecular characterisation revealed that some samples
prepared here have relatively high molecular weight values (about 8 to 10 times
those of commercial grades used as comparisons). The melt and mechanical
properties are very different from the comparisons. Some of the differences can
be explained through molecular weight grounds alone but it is not sufficient.
It is known that an increase in molecular weight causes mechanical properties
to change because networks occur. This is due to molecular entanglements which
Inevitably occur in the longest chains. It is considered that the Improved
properties cannot fully be explained on this basis alone. It is suggested that
the explanation comes from the original polymerisation reaction. In order to
make the polymers^ polymerisation reactions were carried out such a way that
the growing chains could easily entangle with each other. It is suggested that
this idea should be further studied.
Some evidence was also found that some of the entanglements
are destroyed during the working up of the polymers after they have been made.
In the conclusion of the thesis, it is suggested that the
project has to be enlarged to maximise the presence of entanglements which
might lead to the creation of new polymeric grades which could even become gels
in the molten state.
Text
Mathieu 1981 Thesis
- Version of Record
More information
Published date: 1981
Identifiers
Local EPrints ID: 459841
URI: http://eprints.soton.ac.uk/id/eprint/459841
PURE UUID: fc12b67c-ba5b-49e3-91d6-326a343f5b8f
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Date deposited: 04 Jul 2022 17:19
Last modified: 16 Mar 2024 18:34
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Contributors
Author:
Philippe Jean-Marie Mathieu
Thesis advisor:
P.J. Hendra
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