Herein, a novel ultra-high salt hydrophobic associated polymer, UUCPAM, was prepared using acrylamide, acrylic acid, 2-acrylamide-2-methyl propane sulfonic acid and the hydrophobic monomer UUC. Polymerization exothermic test results indicated that the increase in the hydrophobic monomer content led to an increase in the exothermic time, which is considerably conducive to the formation of hydrophobic structures. The scanning electron microscopy and transmission electron microscopy studies showed that the polymer had complex network structures and that this phenomenon was considerably obvious in NaCl solution. The fluorescence probe experiment verified that the critical association concentration of this polymer decreased with an increase in the hydrophobic monomer. Rheology studies indicated that the polymer had good temperature and shear resistance in NaCl solution. Moreover, the apparent viscosity of the polymer remained above 80 mPa s when 0.3 wt% UUCPAM was added at 170 s⁻¹ in 20 000 mg L⁻¹ NaCl solution at 90 °C. The storage modulus that indicated strong elasticity increased with an increase in the polymer concentration. Meanwhile, the number of hydrophobic micro-zones increased, thus forming dense network structures. Therefore, the polymer was found to have excellent salt resistance and extensive application prospects.

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.

Polylactic electrospun porous fibres have been widely used in tissue engineering scaffolds. However, the application of linear polylactic is limited due to its poor hydrophilicity, which leads to phase separation and has been seldom used in porous fibre preparation. Instead, branching polylactic acts as a new effective method to prepare porous fibres because it can increase polylactic polar property and make it easy to be formulated in the following application. In the current study, we prepared an ultra-high molecular weight of high branching polylactic with glycerol as the initiator by controlling the ring-opening polymerization time, adding amount of catalyst and glycerol. The structure, molecular weight and thermal properties of copolymers were tested subsequently. The result showed that the surface of the high branching polylactic films is smooth, hydrophilic and porous. This branching polylactic formed electrospun porous fibres and possessed a strong adsorption of silver ion. Our study provided a simple and efficient way to synthesize branching polylactic polymer and prepare electrospun porous fibres, which may provide potential applications in the field of biomaterials for tissue engineering or antibacterial dressing compared with the application of linear polylactic and 3-arm polylactic materials.