Structure-Property Relationships of Isoprene-Sodium Styrene Sulfonate Elastomeric Ionomers

Polymers containing less than 10 mol % of ions (ionomers) have been studied in depth for their potential in producing polymers with tailored properties for specific applications. A small molar percentage of ions can be incorporated into a polymer to drastically enhance the properties of the polymer. An ionomer that has been studied is that of isoprene copolymerized with sodium styrene sulfonate (poly(I-co-NaSS)). Research has been performed relating to the synthesis and chemical characterization of the copolymers. However, an in depth study of the way the physical properties are affected by a change in ion concentration has not been presented. Thus, it is the goal of this thesis to synthesize a series of poly(I-co-NaSS) copolymers with varying levels of sulfonated styrene and characterize their physical properties. The poly(I-co-NaSS) polymers, containing a range of 1.15 to 4.74 mol % NaSS, were polymerized using free radical emulsion polymerization. The copolymer compositions were confirmed using combustion sulfur analysis. Dynamic light scattering indicated that large aggregates were present in solution. These aggregates were large enough that capillary intrinsic viscosities could not be measured. Small angle x-ray scattering (SAXS) and thermal analysis showed little change as the ion concentration was increased, while tensile, stress relaxation and adhesion properties were improved. The absence of changes in the SAXS patterns indicated that there was an absence of a well-defined ionic aggregate, while the mechanical properties showed evidence of electrostatic interactions. This can be at least partially attributed to ionic interactions on a smaller scale (doublets, triplets).

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Macromolecular Science and Engineering

Department dc:contributor.department

Macromolecular Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2017

Author dc:creator

• Blosch, Sarah Elizabeth

Chairs dc:contributor.committeechair

• Turner, S. Richard
• Moore, Robert Bowen

Committee members dc:contributor.committeemember

• Orler, Edward Bruce
• Riffle, Judy S.

• Ionomer
• isoprene
• sulfonated styrene
• morphology
• mechanical analysis
• structure-property relationship

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Dc Identifier Other

vt_gsexam:12260

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/86362