Polyisobutylene (PIB)-based polymer networks potentially useful as smart coatings for photovoltaic devices have been developed. Low molecular weight coumarin functional triarm star PIB was synthesized via a single step SN2 reaction of bromoallyl functional triarm star PIB with 4-methylumbelliferone or umbelliferone in the presence of sodium hydride. Quantitative end functionality was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. UVA (λmax = 365 nm) induced reversible photodimerization of the coumarin moieties resulted in cross-linked elastomeric films exhibiting self-healing behavior. The extent of photodimerization/photoscission was monitored by UV-vis spectroscopy. The low oxygen (1.9 × 10(-16) mol m m(-2) s(-1) Pa(-1)) and moisture (46 × 10(-16) mol m m(-2) s(-1) Pa(-1)) permeability of the cross-linked polymer films suggest excellent barrier properties of the cross-linked polymer films. The self-healing process was studied by atomic force microscopy (AFM). For this, mechanical cuts were introduced in the cross-linked PIB films through micromachining with an AFM tip and the rate of healing induced by UV, sunlight, or both was followed by taking AFM images of the film at different time intervals during the repair process.

Polyisobutylene‐based UV cured networks potentially useful as sealants were synthesized by photopolymerization of well‐defined polyisobutylene methacrylate (PIB‐MA), acrylate (PIB‐A) and vinyl ether (PIB‐VE) di‐ and trifunctional macromonomers. The kinetics of photocrosslinking were measured using an optical pyrometer apparatus and optimized with respect to different experimental parameters. PIB‐MA/A macromonomers displayed enhanced reactivity in radical photopolymerization in the presence of a bis(acylphosphine) oxide photoinitator. PIB‐VE macromonomers exhibited a high rates of photopolymerization with (4‐n‐octyloxyphenyl)phenyliodonium hexafluroantimonate as the photoinitiator. The rates as well as the ultimate monomer conversions were increased by increasing the irradiation light intensity. The inherent induction period associated with oxygen inhibition in the photopolymerization of PIB‐MA was significantly reduced by optimizing the choice of photoinitiator. A detailed investigation of the concentration of MA/A/VE end groups revealed the presence of a prominent saturation effect in the photopolymerization of PIB‐A, which was absent with PIB‐MA and PIB‐VE. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Azido end-functionalized polyethylenes (PE-N3, 2250 or 2500 g mol–1, Đ = 1.2, functionality higher than 88%) were reacted with alkyne end-functionalized or telechelic polyisobutenes (PIB-CCH: M n = 2400 g mol–1, Đ = 1.1; HCC-PIB-CCH: M n = 6900 g mol–1, Đ = 1.2, respectively) using the 1,3-dipolar cycloadddition reaction in a mixture of toluene and dimethylformamide at 110 °C. The reaction led to the quantitative formation of di- and triblock copolymers (PE-b-PIB and PE-b-PIB-b-PE) that were characterized by size exclusion chromatography and 1H NMR analyses. The original copolymer PE-b-PIB-b-PE that incorporates hard semicrystalline PE blocks and a soft PIB block was further studied by differential scanning calorimetry, optical microscopy, X-ray scattering, and dynamic mechanical analysis. It was shown that the crystallinity of PE segments was not perturbed by the PIB phase and that the T g of PIB was slightly raised because of chain motion restrictions due to PE crystallites. In addition, mechanical analyses showed that PE-b-PIB-b-PE behaved as a thermoplastic elastomer over a broad temperature range (0–110 °C) with a tensile strength of 4 MPa and an elongation at break of 16%. The use of blocks of higher molar mass should improve the copolymer nanostructuration.

b S Supporting Information ' INTRODUCTIONEpoxy resins are a versatile group of thermoset polymers possessing excellent combination of stiffness, strength, chemical resistance, insulating properties, adhesion to substrate, and environmental stability. Thus, these materials find widespread applications in the field of construction, electronics, adhesives, and coatings. 1 One of the important applications of epoxy resins

The syntheses of new polyisobutylene macromonomers with methacrylate, acrylate, vinyl ether, and glycidyl ether end-functionality have been accomplished using simple nucleophilic substitution reactions of bromoallyl end-functional polyisobutylene. Use of a phase transfer catalyst tetrabutylammonium bromide significantly increased the rate of substitution reactions. The macromonomers were characterized by 1 H, COSY, and 13 C NMR spectroscopic, GPC, and MALDI-TOF MS analyses. The end-functionality was calculated to be ∼2 in all the cases. The GPC-RI traces were identical to the precursor bromoallyl telechelic PIB, indicating the absence of side reactions affecting the chain length in the corresponding substitution reactions.