An efficient and facile method of grafting Allyl groups to chemically resistant polyketone membranes

Polyketone is a thermoplastic polymer known for its strong mechanical properties and chemical resistance. Such superiorities make it difficult to process and chemically modify for further functionalizations and applications. In this work, we introduce a novel method for functionalizing the alpha carbon of polyketone. We succeeded to attach allyl groups to the backbone of polyketone by a heterogeneous reaction between polyketone enolate and allyl bromide. Allylated polyketone is not soluble in common solvents. Since we started with a membrane of polyketone, there is no need to cast again. Further functionalization is possible through pending allyl groups via alkene addition reactions and ionic or radicalic polymerization. FTIR, elemental analysis, solid NMR, FT-Raman, SEM and XPS methods were employed to confirm the elemental composition, molecular structure and morphology. In addition, X-ray diffractometer (XRD), UV–Visible spectroscopy and thermal analysis were used to investigate the crystal structure, physical and electronic properties. Grafting pending allyl groups onto polyketone polymer chain. [Display omitted] •First chemical grafting method for heavy-molecular-weight polyketone (PK) polymers.•Carbonyl groups not interfered and only aliphatic part is mainly used for substitution.•Heterogenous reaction allowed a membrane of allylated polyketone (PK-allyl).•Further functionalization of PK-allyl polymer is possible via addition and polymerization.•Flexibility weakens, but membranes preserve thermal and apparent mechanical strength.