Interrogation of a fluoropolymer dispersion manufactured with a non-fluorinated polymerization aid for targeted and non-targeted fluorinated residuals by liquid chromatography high resolution mass spectrometry.

Recent advances in fluoropolymer polymerization have focused on replacing perfluorinated polymerization aids (PAs) with hydrocarbon-based alternatives. Hydrocarbon PAs are vulnerable to fluorinated radicals during polymerization, leading to the creation of hundreds of process-specific polyfluorinated residuals. These residuals, which include low molecular weight extractable or leachable impurities, are challenging to detect at trace levels.

Local and collective motions in precise polyolefins with alkyl branches: a combination of 2H and 13C solid-state NMR spectroscopy.

Branching out: The mobility of linear polymers changes upon branching, which has a pronounced effect on processability and drawability. Regularly branched model polyolefins were studied by advanced solid-state NMR spectroscopy, and twist defects around the branches in the crystalline regions are identified. For lower branch content, the twisting motions are decoupled; for higher content, collective motion is found (see picture).

Modeling branched polyethylene: copolymers possessing precisely placed ethyl branches.

A structural investigation of precise ethylene/1-butene (EB) copolymers has been completed using step polymerization chemistry. The synthetic methodology needed to generate four model copolymers is described; their primary and higher level structure is characterized. The copolymers possess an ethyl branch on every 9th, 15th, and 21st carbon along the backbone of linear polyethylene.

Modeling random methyl branching in ethylene/ propylene copolymers using metathesis chemistry: synthesis and thermal behavior.

The structure of random ethylene/propylene (EP) copolymers has been modeled using step polymerization chemistry. Six ethylene/propylene model copolymers have been prepared via acyclic diene metathesis (ADMET) polymerization and characterized for primary and higher level structure using in-depth NMR, IR, DSC, WAXD, and GPC analysis. These copolymers possess 1.