| With the rapid development of industry, the improvement of standards of people’s life, the increasement of types and amount of waste water, the worse water pollution and the threaten of harmful microbials on human safety and health, it’s eager to realize clean and environmentally frinendly production and green and low-carbon industry. It is a question how to realize sustainable development and enhance industry competition ability. The concept of high value-added products has been advocated recently, and more and more people notice the potential commercial value of the polymer synthesized by pentaerythritol (PER). Initiator bromide pentaerythritol (Br-PER) was prepared by acrylating PER with 2-bromide butyl acyl bromine and the cationic oligomer monomer of guanidine (M-PHGH) was synthesized by grafting Poly(methylene guanidine hydrochloride) (PHGH) with maleic anhydride (MA) in this work. Furthermore, cationic antimicrobial star polymers of guanidine was prepared with M-PHGH and acrylamide (AM) as comonomers, Br-PER as initiator, copper based catalyst as catalyst,2,2’-pyridine as coordination reagent via atom transfer radical polymerization (ATRP) technique in liquid solution. FT-IR, TG,1H-NMR and other methods were used to characterize the structure and thermal stability of M-PHGH, Br-PER and star polymer. Meanwhile, minimum inhibition concentration test (MIC) was used to determine the minimum concentration of star polymer needed to kill Escherichia coli. (E. coli.) and weighing method was used to identify the reaction yield of star polymers. This kind of cationic star-shaped polymer is expected to be applied in the field of flocculation adsorption. Alkaline Ca-bentonite (2mmolCa/lgbentonite) was prepared by the reaction calcium hydroxide and activated clay. Cationic polymer modified alkaline clay has great potential to adsorb anionic dyes (xylenol orange), cationic dye(methylene blue) and chromium(Ⅳ). Cellulose adsorbed with cationic star polymer has obtained excellent antibacterial effect.The researches are as follows:1.The influence of time, reactant ratio, temperature on the reaction conversion of MA was investigated as well. As a result, the reaction conversion of MA can reach 92.4% when the reaction of MA and PHGH (1.2:1, mol/mol) was carried out at 45 ℃for 20 h. Furthermore, the structure characterization showed that MA had been successfully bonded on the chain of PHGH to get M-PHGH, and TG demonstrated that M-PHGH possesses a better thermal stability than PHGH.2. Cationic star polymers were synthesized with Br-PER as initiator, bpy as the coordination agent and CuBr as catalyst under the same temperature and the same reaction time, at different molar ratio of nonionic monomer AM and cationic monomer M-PHGH and at different mole ratio of AM, Br-PER and M-PHGH. The products were characterized by means of IR,1H-NMR, TG and Zeta potential analysis. After the test of the MIC and particle size of polymer, It showed that the reaction yield of star polymer was 75.89% when the reaction was proceeded with the mole ratio of bpy and CuBr was of 2:1, and Br-PER: M-PHGH:AM was of 1:12:240 at 60 ℃. But because of the solubility and the MIC of above products was not ideal, the mole ratio of Br-PER:M-PHGH:AM for 1:12:120 was chosen, at which MIC of the product was 6.25 ppm.3. Cationic polymer modified alkaline clay:(1).Removing the Cr6+ in the solution:optimum process conditions of adsorption was that adsorption process was carried out by shaking at 130 r·min-1 for 16 h at 30 ℃ with pH= 3-4, the adsorption amount of Cr6+ was increased from 0.37 mg·g-1 to 1.31 m·g-1. (2).Removing the dye in the solution:optimum process conditions of adsorption was a):for cationic dye(methylene blue), adsorption experiments were carried out by shaking at 150 r·min-1 for 80min at 30 ℃with pH= 8-9. Samples were centrifuged at 3500r·min-1 and then were collected. Adsorption amount of xylenol orange was improved from 154.74 mg·g-1 to 169.32 mg·g-1; b) for anionic dyes (xylenol orange), adsorption experiments were carried out by shaking at 150r·min-1 for 80min at 30 ℃ with pH= 2-3 and adsorption amount of xylenol orange was enhanced from 45.01 mg·g-1 to 49.21 mg·g-1. These results consistent with the result of Zeta potential charge of particle.4.The shake flask method was adopted to the qualitative analysis of the influence of cationic polymer modified cellulose effects on eE. coli growth inhibition rate. It can be clearly seen that the surface of the cellulose have multilayer adsorption by SEM observation. The cationic polymer modified celluloses have obvious absorption peaks of star polymers by the infrared analysis, which demonstates that the cationic polymer was adsorbed on the surface of cellulose successfully and render the cellulose antimicrobial (over 100% inhibition) to E.coil in the presence of 1.0% (wt) star polymer. |
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