No abstract

No abstract

Six novel perfluoroalkyl-activated bishalo monomers 4a,b−6a,b have been synthesized successfully using Pd(0)-catalyzed cross-coupling reaction of 4-chloro- or 4-fluoro-3-trifluoromethylphenylboronic acid with 1,4-dibromobenzene, 2,6-dibromopyridine, and 2,5-dibromothiophene. These monomers were converted to poly(arylene ether)s by nucleophilic displacement of the halogen atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight-average molar masses up to 3.52 × 105 g mol-1 in GPC. Displacement of the chlorine atoms from the analogous monomer structures by bisphenols was not successful in obtaining high molar mass products. These poly(arylene ether)s showed very high thermal stability even up to 536 °C for 5% weight loss in TGA in synthetic air. Comparatively low thermal stability for the thiophene ring containing polymers was attributed to the oxidation of the sulfur atom of the thiophene ring at high temperature in air, which destroyed the aromatic character of the thiophene ring. This was confirmed by investigating the thermal stability of these polymers in an inert environment. The polymers exhibit glass transition temperatures (T g) up to 234 °C in DSC. The glass transition temperatures taken as peak in tan δ in DMTA measurements are in good agreement with the DSC T g values. All the polymers are soluble in a wide range of organic solvents, e.g., CHCl3, THF, NMP, and DMF. Transparent thin films of these polymers cast from THF exhibited tensile strengths up to 70 MPa, a modulus of elasticity up to 2.69 GPa, and elongation at break up to 30% depending on their exact repeating unit structures.

This work describes the synthesis and characterization of a new series of semifluorinated sulfonated polytriazole copolymers (PTATSH‐XX) with varying degree of sulfonation and higher IEC. The copolymers have been prepared by click reaction using a combination of diazide monomers; a newly synthesized diazide monomer namely 4,4‐bis[3‐trifluoromethyl‐4(4‐azidophenoxy)phenyl]benzene (TAZ) and a commercially available diazide monomer namely 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt (DADSDB) with a bis‐alkyne monomer namely 4,4′‐(propane‐2,2‐diyl)bis((prop‐2‐ynyloxy)benzene) (BPEBPA). The copolymers are well characterized by FTIR and NMR spectroscopy and have exhibited good solubility and film forming abilities along with good thermal and chemical stability, low water uptake, good dimensional stability and high mechanical properties. The TEM micrographs of the copolymer membranes show good phase separated morphology with cluster size in the range 10–60 nm. The proton conductivity values of the copolymer membranes are found in the range of 15–90 mS cm−1 at 80°C and 16–97 mS cm−1 at 90°C. POLYM. ENG. SCI., 57:312–323, 2017. © 2016 Society of Plastics Engineers

A series of polytriazole copolymers were synthesized by the click polymerization of fluorinated dialkyne with a mixture of two different diazide monomers and the proton exchange membrane properties of the copolymers were investigated.