University of Technology of Compiègne, France
University of Technology of Compiègne, France

Time filter

Source Type

Yu X.,The University of AkronAkron | Li Y.,The University of AkronAkron | Dong X.-H.,The University of AkronAkron | Yue K.,The University of AkronAkron | And 5 more authors.
Journal of Polymer Science, Part B: Polymer Physics | Year: 2014

Giant surfactants are polymer-tethered molecular nanoparticles (MNPs) and can be considered as a subclass of giant molecules. The MNPs serve as functionalized heads with persistent shape and volume, which may vary in size, symmetry, and surface chemistry. The covalent conjugation of MNPs and polymer tails affords giant surfactants with diverse composition and architecture. Synthetic strategies such as "grafting-from" and "grafting-onto" have been successfully applied to the precise synthesis of giant surfactants, which is further facilitated by the emergence of "click" chemistry reactions. In many aspects, giant surfactants capture the essential features of small-molecule surfactants, yet they have much larger sizes. They bridge the gap between small-molecule surfactants and traditional amphiphilic macromolecules. Their self-assembly behaviors in solution are summarized in this Review. Micelle formation is affected not only by their primary chemical structures, but also by the experimental conditions. This new class of materials is expected to deliver general implications on the design of novel functional materials based on MNP building blocks in the bottom-up fabrication of well-defined nanostructures. © 2014 Wiley Periodicals, Inc.


Szanka I.,Hungarian Academy of Sciences | Szanka A.,Hungarian Academy of Sciences | Kennedy J.P.,The University of AkronAkron
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2015

Novel rubbery wound closures containing various proportions and molecular weights of polyisobutylene (PIB) and poly(2-octyl cyanoacrylate) [P(OctCA)] for potential clinical use were designed, synthesized, characterized, and tested. Homo-networks were prepared by crosslinking 3-arm star-shaped PIBs fitted with terminal cyanoacrylate groups, [Ø(PIB-CA)3], and co-networks by copolymerizing Ø(PIB-CA)3 with OctCA using N-dimethyl-p-toluidine (DMT). Neat Ø(PIB-CA)3, and Ø(PIB-CA)3/OctCA blends, upon contact with initiator, polymerize within seconds to optically transparent strong rubbery co-networks, Ø(PIB-CA)3-co-P(OctCA). Homo- and co-network formation was demonstrated by sol/gel studies, and structures and properties were characterized by a battery of techniques. The Tg of P(OctCA) is 58 °C by DSC, and 75 °C by DMTA. Co-networks comprising 25% Ø(PIB-CA)3 (Mn=2400 g/mol) and 75% P(OctCA) are stronger and more extensible than skin. Short and long term creep studies show co-networks exhibit high dimensional stability and <6% creep strain at high loading. When deposited on porcine skin co-networks yield hermetically-adhering clear rubbery coatings. Strips of porcine skin coated with co-networks could be stretched and twisted without compromising membrane integrity. The co-network is nontoxic to L-929 mouse fibroblasts. © 2015 Wiley Periodicals, Inc.


Szanka I.,Hungarian Academy of Sciences | Szanka A.,Hungarian Academy of Sciences | Kennedy J.P.,The University of AkronAkron
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2015

The polymerization of 2-octyl cyanoacrylate (OctCA) initiated by five N-bases [N,N-dimethyl-p-toluidine (DMT), pyridine (Pyr), triethyl amine (Et3N), azobicyclo[2.2.2]octane (ABCO), and diazobicylo[2.2.2]octane (DABCO)] was investigated. Our main objective was to assess the suitability and relative reactivity of these initiators for neat OctCA polymerization as wound closure adhesives. Methodologies were developed to determine stir-stop and set times of OctCA polymerization and to use these quantities to assess initiation reactivity. According to these studies Et3N, ABCO, DABCO, and Pyr are most reactive initiators, while DMT is much less reactive. Polymerizations were much faster in the presence of small amounts of tetrahydrofuran than toluene, indicating solvent polarity effects. Initiator reactivity is discussed in terms of structural parameters. NMR and MALDI-TOF analyses of low molecular weight P(OctCA) prepared with DMT did not show evidence for the expected aromatic head group proposed by earlier investigators, which suggests complex initiation mechanism. © 2015 Wiley Periodicals, Inc.

Loading The University of AkronAkron collaborators
Loading The University of AkronAkron collaborators