Di-azides cross-linked, iPP/EPDM-based thermoplastic vulcanizates
(2311-2320) European Polymer Journal 47  #12 (2011)
Zielińska et al, Netherlands, investigated two di-azidoformates: 4,4′-isopropylidenediphenyl azidoformate (4,4′DAF), and tri(ethylene glycol)-di(azidoformate) (GDAF), and one di-sulfonyl azide: 1,3-benzenedisulfonyl azide (1,3BDSA), as cross-linking agents for iPP/EPDM-based dynamically vulcanized thermoplastic vulcanizates (TPVs).  With respect to the production conditions of the investigated TPVs, the reaction temperature of the sulfonyl azide makes it the most suitable cross-linking agent.  (RDC 11/16/2011)

Using a polymer-supported azide ion in [2+3] cycloaddition reaction of azide ion with nitriles
(1977–1982)Journal of Applied Polymer  Science 123 #4 (2012)
Zarchi and Nazem of Yazd University, Iran, showed that the  [2+3] cycloaddition between various nitriles and crosslinked poly(4-vinylpyridine) supported azide ion proceeds smoothly in the presence of ammonium bromide or ammonium chloride in N,N-dimethyl formamide, to give the corresponding 5-substituted-1H-tetrazoles in good to high yields.  Conventional heating was used to promote reaction. It was found that using nitriles with electron-withdrawing groups result in bout higher yields and lower reaction times.   (RDC 11/2/2011)

051[2011]  Furan-based polysemiacylcarbazides by polyaddition of bis(furanic hydrazide)s with diisocyanates
e-Polymers(6/14/2011) (56)
[Abstract]
Ghorbel et al of the Université Pierre et Marie Curie, France, applied a solution polyaddition procedure to prepare furanic polyacylsemicarbazides based on 2,2-isopropylidene-bis(5-(2- furoyl) hydrazide) and aliphatic or aromatic diisocyanates.  . High MW soluble polymers were obtained after 12h reaction at 20°C with 0.2 M monomer solutions in dimethylacetamide. These furan-based polyacylsemicarbazides are thermally stable up to 290° C, but exhibit a complex thermal behaviour. This was explained by the cyclohydration of acylsemicarbazide groups into NH-substituted oxadiazoles, resulting in rigid and high melting polymers, less stable, however, than conventional aromatic polyoxadiazoles.  (RDC 6/14/2011)

Azidation of polyesters having pendent functionalities by using NaN3 or DPPA–DBU and photo-crosslinking of the azidopolyesters
(272-278) Polymer Journal 43 #3 (2011)
Abstract
Shibata et al Nagoya Institute of Technology, Japan, carried outdehydration polycondensation of bromosuccinic acid and methylsuccinic acid with 1,4-butanediol at 80 °C to synthesize aliphatic polyesters containing pendent bromo groups without dehydrobromination using scandium trifluoromethanesulfonate (Sc(OTf)3) as the catalyst. Azidation of the resultant polyesters was carried out readily in N,N-dimethylformamide at room temperature using sodium azide (Mn=8.3 × 103 (Mw/Mn=2.17)).  1H nuclear magnetic resonance analysis of the product revealed that 65% contained azide functionality, and dehydrobromination occurred in 35% during the azidation process.  On the other hand, azidation of poly(butylene bromoadipate-co-butylene methylsuccinate) (poly(BBA-co-BMS)) proceeded successfully under the same conditions to generate poly(butylene azidoadipate-co-butylene methylsuccinate) (poly(BAA-co-BMS)) without dehydrobromination (Mn=10.4 × 103 (Mw/Mn=2.71)). We successfully photo-crosslinked the resultant azidopolyester by ultraviolet irradiation and examined it using scanning electron microscope. We also described azidation of polyesters having pendent hydroxyl groups by using the ‘DPPA (diphenylphosphoryl azide)–DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) substitution strategy’ to produce water-soluble polyesters containing pendent azido groups (Mn=7.5 × 103 (Mw/Mn=2.25)). These azidopolyesters might be extremely useful not only for their derivatization by simple chemical modification but also for their effective utilization as photolithography material. (RDC 6/8/2011)

Azide-based Cross-Linking of Polymers of Intrinsic Microporosity (PIMs) for Condensable Gas Separation
(631–636)Macromolecular Rapid Communications 32 #8 (2011)|
Du et al, Canada, Saudi Arabia and South Korea, prepared cross-linked polymers of intrinsic microporosity (PIM)s for gas separation membranes, by a nitrene reaction from a representative PIM in the presence of two different diazide cross-linkers.  The homogenous membranes were cast from THF solutions of different ratios of PIM to azides.  The resulting cross-linked structures of the PIMs membranes were formed at 175 °C after 7.5 h.  These resulting cross-linked polymeric membranes showed excellent gas separation performance and can be used for O2/N2 and CO2/N2 gas pairs, as well as for condensable gases, such as CO2/CH4, propylene/propane separation. Most importantly, and differently from typical gas separation membranes derived from glassy polymers, the crosslinked PIMs showed no obvious CO2 plasticization up to 20 atm pressure of pure CO2 and CO2/CH4 mixtures.  (RDC 5/26/2011)