Chemistry

Permanent URI for this community

https://hdl.handle.net/2440/4284

Browse

Browsing Chemistry by Author "Abdala, A."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    ItemMetadata only
    Model associative polymer networks generated by inclusion interaction between polymers with cyclodextrin and hydrophobic grafts
    (American Chemical Society, Division of Polymer Chemistry, Inc., 2004) Xuhong, G.; Abdala, A.; Prud'homme, R.; Lincoln, S.; Khan, S.
  • No Thumbnail Available
    ItemMetadata only
    Novel associative polymer networks based on cyclodextrin inclusion compounds
    (Amer Chemical Soc, 2005) Guo, X.; Abdala, A.; May, B.; Lincoln, S.; Khan, S.; Prud'homme, R.
    A new routine to synthesize α- and β-cyclodextrin (CD)-modified PAA and a novel associative polymer networks based on mixture of CD-modified and hydrophobically-modified (HM) poly(acrylic acid) (PAA) were described. It was shown that the inclusion interactions between CD and hydrophobe grafts in PAAs lead to stronger associations and solution viscosities than purely hydrophobic interactions at the same polymer concentration. The cyclodextrin inclusion is strictly binary, and its strength can be tuned by the choice of CD and hydrophobic species. The screening of the association between hydrophobically modified PAA by free α- or β-cyclodextrins occurs at approximately a stoichiometric ratio of cyclodextrin to hydrophobe.
  • No Thumbnail Available
    ItemMetadata only
    Rheology control by modulating hydrophobic and inclusion associations in modified poly(acrylic acid) solutions
    (Elsevier, 2006) Guo, X.; Abdala, A.; May, B.; Lincoln, S.; Khan, S.; Prud'homme, R.
    The rheology of modified poly(acrylic acid) (PAA) solutions can be tuned by controlling the inclusion interactions between α-cyclodextrins and alkyl hydrophobes. We demonstrate three modes of control: (1) using free cyclodextrins (CD) to displace hydrophobe-hydrophobe association in hydrophobically modified poly(acrylic acid) (HMPAA) polymers-which reduces fluid viscosity, (2) using competitive inclusion interactions where stronger SDS:CD binding can be used to 'unmask' CD:hydropobe inclusion interactions-which increases viscosity, and (3) employing HMPAA inclusion interactions with CD groups grafted to PAA chains (CDPAA)-which produces higher viscosities than purely hydrophobic association systems at the same concentration. The inclusion association between alkyl side-group in HMPAA and CD, either free or grafted onto PAA, obeys a 1-to-1 stoichiometry at low polymer concentrations (<1 wt%). In contrast to purely hydrophobically associating polymers, the CD:hydrophobe interaction is only binary, and, therefore, these associated networks should be ideal model systems to test theoretical predictions for associative fluids. © 2006 Elsevier Ltd. All rights reserved.