Cationic hyperbranched oligomer poly(N-acryloyl-1,2-diaminoethane hydrochloride) (HADE) was firstly synthesized by
Michael addition reaction. And then, a series of cationic flocculants poly(acrylamide/N-acryloyl-1,2-diaminoethane hydrochlorides) (PAM-HADEs) with hyperbranched structure was prepared from HADE as macro-monomer and acrylamide (AM).
The structures of PAM-HADEs were characterized by Fourier transform infrared spectrometry, 1H and 13C nuclear magnetic
resonance spectroscopy, gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time of flight
mass spectrometry (MALDI-TOF). And the properties were systematically evaluated by intrinsic viscosity, zeta potential
and hydrodynamic radius. The mechanism of the cationic hyperbranched copolymer used in water treatment was extensively
studied via a jar test in which the transmittance of the supernatant, settling time, and average floc size were used to evaluate
the flocculability. Compared with the linear flocculant poly (acrylamide/liner-N-acryloyl-1,2-diaminoethane hydrochloride)
(PAM-LADE), the novel hyperbranched polymeric flocculants exhibited outstanding flocculability which were reflected
by shorter settlement time, high transmittance and large floc size. The primary cause that PAM-HADEs owned excellent
flocculability is the more stretching configuration and less chains entanglement of PAM-HADEs in waste-water due to their
hyperbranched structure compared with that of the linear PAM-LADE which exhibited curly coil configuration. On the other
hand, abundant and exposed cationic terminal groups of PAM-HADEs originated from their hyperbranched structure also
hint higher flocculation capacity. At optimum dosages of the polymer, the transmittance of the supernatant is less at low and
high pH values, indicating that the natural pH (pH 7.29) of the suspension is the most appropriate pH for the flocculation

• A Novel Hyperbranched Polymeric Flocculant for Waste-Water Treatment