Shaobo Dong,Yazhen Wang,Tianyu Lan,Jianxin Wang,Liwu Zu,Tianyuan Xiao,Yonghui Yang,Jun Wang
Polystyrene (PS) is widely used in our daily life, but it is flammable and produces a large number of toxic gases and high-temperature flue gases in the combustion process, which limit its application. Improving the flame retardancy of PS has become an urgent problem to be solved. In addition, in view of the disadvantage that small-molecule flame retardants can easily migrate from polymers during use, which leads to the gradual reduction of the flame retardant effect or even loss of flame retardant performance, and the outstanding advantages of ATRP technology in polymer structure design and function customization, we used ATRP technology to synthesize the high-molecular-weight bifunctional additive PFAA-DOPO-b-PDEAEMA, which has flame retardant properties and antistatic properties. The chemical structure and molecular weight of PFAA-DOPO-b-PDEAEMA were characterized by FTIR, 1H NMR, GPC, and XPS. When the addition of PFAA-DOPO-b-PDEAEMA was 15 wt %, the limiting oxygen index (LOI) of polystyrene composites was 28.4%, which was 53.51% higher than that of pure polystyrene, the peak of the heat release rate (pHRR) was 37.61% lower than that of pure polystyrene, UL-94 reached V-0 grade, and the flame retardant index (FRI) was 2.98. In addition, when the PFAA-DOPO-b-PDEEMA content is 15 wt %, the surface resistivity and volume resistivity of polystyrene composites are 2 orders of magnitude lower than those of polystyrene. This research work provides a reference for the design of bifunctional and even multifunctional polymers.
Using SI-ATRP technique, 1-vinylimidazole (VI) monomer was directly modified onto the surface of CMPS resin to prepare a chelating resin (PVI-g-PS) with imidazole ring as functional group. The adsorption properties of Cd(II), Ni(II), Pb(II) and Cu(II) were studied. It was found that with the increase in ATRP time and the amount of VIM, the graft ratio of VIM increased linearly, which indicated that the density of imidazole ring on the surface of resin increased. Adsorption experiments showed that the resin has good adsorption properties for Cd(II), Ni(II), Pb(II) and Cu(II). At pH 5.0, the static saturated adsorption amount of PVIM-g-PS for Cd(II), Ni(II), Pb(II) and Cu(II) was 2.82, 1.77, 1.22 and 0.83 mmol g −1 , respectively. The adsorption model could be described by Langmuir isothermal adsorption and the adsorption process accorded with quasi-first-order kinetic equation. In addition, the resin has good desorption rate and reusability. These findings suggest that the resin can be potentially applied to the efficient removal of heavy metal ions from wastewater.