The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-...The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-OXZ)] was synthesized by transforming the living free radical polymerization into ring-opening polymerization of 2-methyl-2-oxazoline.The obtained copolymers were characterized by SEC, IR and 1H NMR. The suitable polymerization conditions for block copolymer synthesis were studied.展开更多
By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the...By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the effects on sol particle growth and network &morphology control were discussed in detail, and then the model on sol particle growing was suggested on the basis of growth unit theory of anion coordinate polyhedron. The results showed that PEO PPO PEO additive limited particle growth but also restrained particle agglomeration and then made the SiO2 sol high stable. It was found that the action of EPE was similar to that of organic structure directing agent and made the sol cluster cross linked branch network.展开更多
文摘The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-OXZ)] was synthesized by transforming the living free radical polymerization into ring-opening polymerization of 2-methyl-2-oxazoline.The obtained copolymers were characterized by SEC, IR and 1H NMR. The suitable polymerization conditions for block copolymer synthesis were studied.
文摘By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the effects on sol particle growth and network &morphology control were discussed in detail, and then the model on sol particle growing was suggested on the basis of growth unit theory of anion coordinate polyhedron. The results showed that PEO PPO PEO additive limited particle growth but also restrained particle agglomeration and then made the SiO2 sol high stable. It was found that the action of EPE was similar to that of organic structure directing agent and made the sol cluster cross linked branch network.