Novel molecular architectures from iptycene polymers

This thesis explored the incorporation of iptycenes into polymers as a means to enhance the mechanical properties. Iptycene structures were targeted because they possess a unique structural property called internal molecular free volume. When these bulky pendant groups are incorporated into the backbone of a polymer chain, they produce a novel chain architecture called molecular barbed wire. This molecular barbed wire architecture not only influences individual polymer chain dynamics but also induces lateral interactions between polymer chains through the minimization of internal molecular free volume. Work began by developing the concepts of internal molecular free volume and how to exploit its minimization. A formal definition for this property was created along with methods to identify and quantify its existence. Experimental results document the effects of introducing this property into polyesters and polycarbonates. Two specific novel inter-chain interactions were established: molecular threading and molecular interlocking. These steric interactions between polymers chains generate a non-bonded, network morphology and actively enhance the mechanical properties during deformation.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Tsui, Nicholas T. (Nicholas Tang)

Advisor dc:contributor.advisor

• Edwin L. Thomas.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/39544

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39544