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In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate– co -acrylic acid- co -diallyldimethylammonium chloride) (P(SS- co -AA- co -DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS- co -AA- co -DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS- co -AA- co -DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS- co -AA- co -DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS- co -AA- co -DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS- co -AA- co -DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS- co -AA- co -DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.

In this study, a type of polymeric fluorescence brightener (PFB) with a triazine–stilbene structure was synthesized through a three‐step condensation reaction, and the performance of this PFB on antiyellowing was also investigated by the whiteness of paper coated with the as‐prepared PFB. Fourier transform infrared spectra revealed that the chlorine atom (·Cl) was substituted by a poly(vinyl alcohol) (PVA) group ([CH2CHOH]n). According to the UV aging experiment, the PFB not only enhanced the whiteness of the paper but also improved the anti‐UV aging properties [compared to those of VBL 4′‐double‐(6‐diethanolamine‐4‐sulfanilic acid‐1,3,5‐triazine‐2‐amino)‐stilbene‐2,2′‐disulfonic acid sodium, a type of commonly used fluorescent whitening agent as a light stabilizer and fluorescent brightening agent]. Moreover, the results of UV–visible spectra indicated that the substitution of PVA suppressed the isomerization of trans conformers to cis conformers under UV light irradiation; this was attributed to the big space steric hindrance of PVA in the as‐prepared samples being restricted the isomerization reaction. Meanwhile, the solubility of the as‐prepared sample was also improved because more hydroxyl groups were introduced into the PFB with the substitution of PVA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45536.