Synthesis and Assembly of Butyl Rubber–Poly(ethylene oxide) Graft Copolymers: From Surface Patterning to Resistance to Protein Adsorption

Abstract

The patterning of copolymers on surfaces is of interest both for a fundamental understanding of polymer assembly processes and for applications ranging from microelectronics to biomaterials. Graft copolymers can provide new opportunities to control polymer composition and architecture, thus opening possibilities for new assembly processes and patterns. In this work, the reaction of a butyl rubber derivative functionalized with activated carbonates along the polymer backbone was reacted with amine terminated poly(ethylene oxide) (PEO–NH2) to provide butyl rubber–PEO graft copolymers. The high efficiency of this reaction allowed for control of the PEO content by the number of equivalents of PEO–NH2 used and its molecular weight, providing a small library of graft copolymers. This approach also provided butyl rubber–PEO graft copolymers with unprecedentedly high PEO content. Thin films of the polymers, prepared by spin-casting were studied by a number of techniques including atomic force microscopy, polarized optical microscopy, profilometry, and confocal fluorescence microscopy following the adsorption of a fluorescent protein. Interestingly, as the PEO content of the copolymers increased, an evolution from complex micrometer scale to nanometer scale patterns was observed. This was accompanied by resistance of the surfaces to protein adsorption at high PEO content, demonstrating that function can evolve from the complex interplay of thermodynamic and kinetic factors governing the assembly of these thin films.

Synthesis, properties and degradation of polyisobutylene-polyester graft copolymers

“…Overall, these results are in agreement with previous reports of linear block copolymers of PIB and PCL, where the incorporation of longer PCL blocks and higher PCL content resulted in T m values similar to those of the bulk PCL . The observation of T m values lower than those of the bulk semicrystalline polymer for shorter polymer grafts and lower graft content is consistent with our previous observations for PIB–PEO graft copolymers . In the case of PDLLA, bulk PDLLA‐OH‐2800 is amorphous with a T g of 29 °C.…”

“…FTIR spectra of all of the graft copolymers had strong peaks at 2950 cm −1 corresponding to aliphatic C‐H bond stretching on both PIB and the polyester and at 1750 cm −1 corresponding to C=O bond stretching on the polyester (Figs S11 and S12). The molar masses of the graft copolymers could not be determined by SEC due to anomalous behavior of these PIB graft copolymers in SEC, which has been reported by our group and others . However SEC did confirm the absence of ungrafted polyester in the copolymers (Figs S13 and S14).…”

“…Utilizing our efficient chemistry for the preparation of graft copolymers from butyl rubber, we report here the synthesis and study of graft copolymers with PCL and PDLLA. While PCL is semicrystalline, the PDLLA stereochemical form of PLA is selected in order to study the influence of a glassy block.…”

Polyisobutylene‐paclitaxel conjugates with pendant carboxylic acids and polystyrene chains: Towards multifunctional stent coatings with slow drug release

“…58 As previously reported, PIB-MA can also be opened by hydroxyl-terminated polymers such as PS (PS-OH) and PEO. 40 While PIB-PEO graft copolymers have been extensively reported by our group and others, [28][29][30]32,59,65,66 PS was of particular interest due to the use of SIBS in stent coatings. Linear block copolymers of PIB with PS or polyalloocimene have been found to exhibit thermoplastic elastomeric (TPE) properties that are conducive to their application in stent coatings.…”

“…[21][22][23][24][25][26][27] While most of these reactions afford incomplete reactions or mixtures of different products and isomers, 25,26,[28][29][30] we have recently reported a clean and efficient epoxidationelimination sequence for introducing allylic alcohol groups to the backbone. 31 These alcohol groups were activated and functionalized to prepare graft copolymers [31][32][33] and have also been further derivatized to afford carboxylic acid groups. 34 The carboxylic acid groups imparted increased tensile strength, which was proposed to result from crosslinking through hydrogen bonding, 24,35,36 as well as enhanced adhesion to stainless steel as a result of binding between the carboxylic acid groups and the metal surface.…”