Sulfonyl azides—an alternative route to polyolefin modification

Abstract

Low-density polyethylene was modified to incorporate aniline moieties by reactive processing with 4-aminobenzenesulfonyl azide. Under melt-processing conditions, the loss of nitrogen produces a sulfonyl nitrene which, in the singlet state, interacts with the substrate primarily by C-H insertion. Polymeric blends prepared from aniline-grafted polyethylene and nylon-66 showed improved tensile and impact properties over and above nylon blended with virgin polyethylene.

Post‐Polymerization Modification of Materials using Diaryldiazomethanes: Changes to Surface Macroscopic Properties

“…If these processes were run at a lower temperature (120 °C), in which polymer degradation did not occur, only the more reactive polymer (polystyrene) was modified, and UHMWPE was recovered unchanged. These results were confirmed from a literature report which indicated that the successful modification of UHMWPE with sulfonyl azides could only be achieved at the elevated temperature and pressure conditions achieved by melt processing . We therefore considered sulfonyl azides to be unsuitable candidates for further development.…”

“…Literature precedent for the use of azides as labeling agents as precursors for the insertion of nitrenes specifically into amines and sulfur functional groups, but also non‐specifically, suggested that they may also be suitable for surface modification more generally. Our own work (Scheme ), however, indicated that, although successful modification of cross‐linked polystyrene could be achieved with the activated amino sulfonyl azides 2 (R = H), prepared using the literature method, low surface energy polymers, exemplified by ultra high molecular weight polyethylene (UHMWPE), could not, since the high thermolysis temperatures (170 °C) for conversion into the required nitrene generally led to concomitant polymer degradation. If these processes were run at a lower temperature (120 °C), in which polymer degradation did not occur, only the more reactive polymer (polystyrene) was modified, and UHMWPE was recovered unchanged.…”

Catalytic activity correlation of Ni(II), Co(II) and Pd(II) complexes to metal atom net charge

“…Polyolefins are among the most important forms of commercial plastics due to their low cost and versatile properties [1] . The discovery of catalysts for the synthesis of such materials remains a challenging problem [2] .…”

Cross-linking and modification of saturated elastomers using functionalized azides

“…[72][73][74][75][76][77][78][79][80][81][82][83] The azides were mixed into the polymers via simple milling or extrusion, as well as they could be dissolved in a polymer-containing solution. Modifications similar to cross-linking were performed using sulfonyl azide and azidoformate compounds.…”

“…More recently, different authors modified LDPE and SBR rubber using a mono-sulfonyl azide compound containing an aniline functionality, Scheme 2.16. 79,80 The mono-azides were also applied as silica coupling agent and for fibre/polyolefin modification. Overall, the largest problem, during the modification is that despite an increase in azide loading the changes in grafting efficiency are very small.…”