A bromine-containing poly(arylene ether sulfone) was synthesized from a(4-bromo)phenylhydroquinone monomer.A phosphonated derivative was prepared based on above brominated polymer using palladium-catalyst.Aimed at improving the properties for fuel cell applications,a composite membrane was obtained by incorporating sulfonic acid-functionalized polysilsesquioxane into the phosphonated polymer through a sol-gel processing.Both phosphonated membrane and its hybrid membranes show good thermal and dimensio-nal stability.The hybrid membrane has low methanol permeability of 1.07×10-7 cm2/s and proton conducti-vity of 0.06 S/cm at 80 ℃.
A novel aromatic polyethersulfone bearing a(3-methoxy)phenyl group(PPES-OMe)was synthesized via an aromatic nucleophilic substitution reaction.A hydroxyl-containing polyethersulfone(PPES-OH)was successfully obtained via a demethylation reaction of PPES-OMe.A series of nano-hybrid materials could be prepared with sol-gel method and FTIR results suggested the chemical bond formed between the hydroxyl group of PPES-OH and TEOS.Nano-size SiO2 particles were observed to disperse uniformly in the polyethersulfone matrix by SEM.It was found that all the films based on these materials were flexible.
A novel type of crosslinkable poly(aryl ether sulfone)(PAES) bearing an allyl pendant(PES-OAllyl) was synthesized by a grafting reaction of hydrophenyl-containing PAES(PES-OH) and allyl bromide. PES-OH was prepared by a demethylation reaction of a methoxyphenylated PAES(PES-OCH3) in the presence of pyridine/hydrochlo- ride. The PES-OCH3 was synthesized by an aromatic nucleophilic substitution of bis(4-chlorophenyl)sulfone and (p-methoxy)phenylhydroquinone. Both DSC and solubility investigation were used to study the crosslinking behavior of PES-OAllyl. After heat treatment, the glass transition temperature(Tg) value of PES-OAllyl sharply increased from 165 ℃ to 227 ℃. Meanwhile, PES-OAllyl changed from a soluble polymer to an insoluble thermoset. In addition, TGA(thermogravimetric analysis) result suggests that the thermal stability of the crosslinked product was improved. All the data prove that the crosslinked PES-OAllyl could be a potential solvent-resistance high-performance material.
YU Yun-wu XING Yan GUO Mei-mei LIU Bai-jun JIANG Zhen-hua
