Molecular order at polymer surfaces via X-ray photoelectron spectroscopy

Molecular order in surfaces is probed for several different repeat unit Spectroscopy (XPS) is chemistries. X-ray Photoelectron used, particularly with angular dependence, to obtain the compositional gradient information from the top 6 run of the surface. It is found that all materials investigated present some kind of preferential and reproducible ordering effect. The ordering ef feet can be present in different forms, such as preferential segregation of a crystalline block to the surface, segregation of a component of different crystalline structure to the surface or orientation of a backbone segment of the polymer towards the surface of the specimen. Polyethylene terephthalate shows an increasing amount of crystalline cyclic oligomer at the surface as the degree of crystallinity of the matrix increases. Block copolyesters unsaturated blocks present containing saturated and the saturated blocks preferentially segregated toward the surface. Crystalline ethylene/chlorotrifluoroethylene alternating copolymer shows the preferential orientation of ethylene groups closer to the surface. The linear polyurethanes studied reveal the surfaces enriched with soft segments, whereas no enrichment was observed for a crosslinked polyurethane.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Engineering

Department dc:contributor.department

Materials Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1984

Author dc:creator

• Barragan, Leonardo C. Lopez

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/76408

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/76408