Quasi-Hydrogen Bond and Charge-Trapping Effect Originating\nfrom Polar Side Group Lead to Significantly Suppressed Charge Transport\nin Polypropylene

How\nto fundamentally suppress charge transport is one of the essential\nissues in polymer dielectrics. This work reports significant charge\ntransport suppression by glycidyl methacrylate (GMA) side group modification\non polypropylene (PP). Experimental and computational investigations\ndiscover for the first time a quasi-hydrogen bond effect generated\nby carbonyl and epoxide of GMA in PP inter/intramolecular structure,\nwhile introducing trap energy levels within the HOMO–LUMO gap.\nThese energy levels suppress the leakage current of GMA-modified PP\nthanks to the charge-trapping effect. The quasi-hydrogen bond originating\nfrom the interaction between the high-polar GMA group and flexible\nPP chain raises the thermostability while averaging the electron distribution\nbetween hydrogen and acceptor oxygen, which is conducive to lessening\nelectric weak points, suppressing charge transport, and finally enhancing\nthe electrical breakdown strength. This work provides new thinking\non polymer dielectric design and charge transport regulation utilizing\nelectron structure and weak interaction at the molecular scale.