Yazhen Wang,Qing Yang,Liwu Zu,Shaobo Dong,Tianyu Lan
Graphical In this work, we successfully prepared PAM-b-DOPOAA block copolymers using the ATRP method. The analysis showed that the ATRP method can regulate the chain segment length and ratio of the resulting polymer with a narrow molecular weight distribution. The prepared block copolymers can be used as a good flame retardant antistatic agent. Polyacrylamide has been a hot topic of research in recent years, however, the preparation of block copolymers of polyacrylamide using ATRP method has been little studied. In this paper, polyacrylamide with reactive group bromine (PAM−Br) was synthesized by atom transfer radical polymerization (ATRP) using acrylamide (AM) as the monomer and water as the solvent, and polyacrylamide was used as the macromolecular initiator for the next reaction step. Then 9,10-dihydro-9-oxa-10-phosphafi-10-oxide (DOPO) was organically modified to obtain acrylate monomers with DOPO functional groups (DOPOAA), and a mixture of water and N, N-dimethylformamide (DMF) was used as the solvent to obtain PAM-b-DOPOAA block copolymers with controllable molecular mass and narrow molecular mass distribution. The effects of the molecular mass of the macromolecular initiator, polymerization time, and the molar ratio of catalyst to the ligand on the polymerization process were investigated. The structure and properties of the products were also characterized by 1 H-NMR, FTIR, XPS, DSC, TG, etc. The PAM-b-DOPOAA prepared by ATRP method can artificially design the length and ratio of the two chain segments, realizing one additive with two functions and the permanent existence of the function of polymer additives.
A facile method to endow porous membranes with high coverage of zwitterionic components on surface was described. The amphiphilic precursor poly(vinylidene fluoride)- graft - N , N -dimethyl aminoethyl methacrylate (PVDF- g -PDMAEMA) was firstly synthesized via ATRP method and then blended with PVDF to prepare flat membranes. The 3-bromopropionic and 1,3-propane sultone were then used as quaternization agent to transit the PDMAEMA into poly(zwitterions) through an surface reaction by treating membranes under a mild condition. The reaction kinetics was investigated, finding that 1,3-propane sultone was more reactive than the 3-bromopropionic. The X-ray photoelectron spectroscopy (XPS) confirmed that nearly 70% of PDMAEMA had been quaternized in 48 h for the 1,3-propane sultone, while only 62% of PDMAEMA was transited for the 3-bromopropionic in 96 h. The porosity determination indicated that the specific area had decreased obviously after the membranes being modified. Morphology changes were found to be responsible for the decreased water fluxes and increased retentions when zwitterions were formed. The successful modification was confirmed by the nice biocompatibility that no platelets adhesion as well as proteins deposition was observed on modified membranes.
危险品化学品经营许可证（带存储）