Surface modification of wheat gluten films for improved water resistance
2010 (English)In: ACS National Meeting Book of Abstracts, 2010Conference paper (Refereed)
Renewable packaging materials are of interest for a more sustainable environment, and wheat gluten (WG) is one of the most interesting candidates to replace petroleum-based oxygen-barrier polymers for packaging applications. This is due to its attractive combination of flexibility and strength, high gas (especially O 2) barrier properties under low humidity conditions and renewability. The main drawback of WG, as with most biopolymers, is its water and moisture sensitivity. The aim of this study was therefore to improve the hydrophobicity of WG films by means of surface modification while maintaining the excellent O 2 barrier properties. The surface modification work included a combination of electrospinning of WG fibers and different plasma surface modifications. The latter involved He plasma treatment for crosslinking the WG film prior to the deposition of electrospun WG fibers, O 2/Ar plasma etching of the WG films with and without electrospun WG fibers for increasing the surface roughness, and plasma polymerization of hexamethyldisiloxane (HMDSO) and other hydrophobic precursors for hydrophobicity. The plasma polymerization trials were performed both at reduced and atmospheric pressure conditions. The aim of the combined work was to maximize the hydrophobicity by combining a suitable nano-microstructure of the WG fibers with the hydrophobicity of the plasma-deposited coatings. The surface modification work was mainly evaluated by means of water contact angle measurements (hydrophobicity), Scanning Electron Microscopy (surface structures), Water Vapor Transmission Rate (WVTR) (moisture barrier) and Oxygen Transmission Rate (OTR) measurements (oxygen barrier). The surface modification work resulted in significantly improved hydrophobic properties of the WG films. The initial water contact angle increased from 65 to 110-130 degrees, depending on the combinations of electrospinning and plasma modification conditions. The plasma coatings prepared at ambient conditions resulted in slightly lower contact angles compared the plasma coating prepared at reduced pressure. The WVTR and OTR measurements are still in progress and will be reported at the meeting.
Place, publisher, year, edition, pages
, ACS National Meeting Book of Abstracts, ISSN 0065-7727
IdentifiersURN: urn:nbn:se:kth:diva-150078ScopusID: 2-s2.0-79951469223OAI: oai:DiVA.org:kth-150078DiVA: diva2:746182
240th ACS National Meeting and Exposition, 22 August 2010 through 26 August 2010, Boston, MA, United States
QC 201409122014-09-122014-08-292014-09-12Bibliographically approved