Network defects in vulcanised rubber


The molecular weight of natural rubber is very high and must be reduced by mastication so that it has sufficient plasticity to enable the incorporation of compounding ingredients. Such a reduction in molecular weight increases the number of elastically ineffective chain ends which reduces the physical properties of vulcanisate. This thesis describes an attempt made to decrease the number of free chain ends by combining them with radical acceptors that will form vulcanisable end groups. These will form cross-links during the vulcanisation process and tie the free chain ends into the network. Such vulcanisates produce significantly better physical properties. A method to quantitatively assess the reduction in free chain ends has been developed. It is necessary to carry out the mastication process under nitrogen as competition from oxygen, which acts as a powerful radical acceptor, reduces the yield of reactive end groups. This improves a serious practical limitation on the method.

Divisions: College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry
Additional Information: (c) Gholam-Reza Bakhshandeh, 1979. Gholam-Reza Bakhshandeh asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately. Department: Chemistry
Institution: Aston University
Uncontrolled Keywords: Rubber,Defects,Mastication,Radical Acceptors
Last Modified: 08 Dec 2023 08:09
Date Deposited: 13 Jan 2011 11:47
Completed Date: 1979-05
Authors: Bakhshandeh, Gholam-Reza

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